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ECOLOGY Community- a group of different species that live together in one area

Ecosystem- An ecosystem includes all of the organisms as well as the climate, soil, water, rocks, and other nonliving things in

an area.

Biosphere –all organisms and the part of Earth where they exist.

Biota –collection of living things Hydrosphere – collection of Earth’s water bodies, ice and water vapor Geosphere- features of Earth’s surface – such as continents and the sea floor – and everything below Earth’s surface. Climate – average long-term weather pattern of a region.

Biome- a major regional or global community of organisms.

Estuary-partially enclosed body of water found where a river flows into the ocean Biotic- factors are living things such as plants, animals, fungi, and bacteria

Abiotic- factors are nonliving things, such as temperature, moisture, wind, rocks, and sunlight

Biodiversity- the variety of living things or different number of species in an ecosystem

Keystone species- a species that has an unusually large effect on its ecosystem

Producers- organisms that make their own food

Autotroph- Producers are also called this

Consumer- organisms that get their energy by eating other organisms, including plants and animals.

Heterotrophs- consumers are also called this

Chemosynthesis- producers in the ocean floor that are bacteria or prokaryotes that can make their own food, using

chemicals

Food chain- shows the feeding relationships for a single chain of producers and consumers. Herbivores- are organisms that eat only plants

Carnivores-are organisms that eat only animals

Omnivores-are organisms that eat both plants and animals

Detritivores-are organisms that eat dead plant and animal matter

Decomposers- are detritivores that break down plant and animal matter into simpler compounds

Specialists- organisms that have a very selective diet and eat only certain things Generalists- organisms that eat a variety of different organisms.

Trophic level-each link in a food chain is a level of feeding or trophic level

Producers are the bottom trophic level

Primary consumers- herbivores that eat producers

Secondary consumers –carnivores that eat herbivores

Tertiary consumers- carnivores that eat secondary consumers

Food Web- shows the complex network of feeding relationships and the related flow of energy

Biogeochemical cycle- the movement of a particular chemical through the living and nonliving parts of an ecosystem

Nitrogen fixation- process by which certain types of bacteria can turn nitrogen gas into ammonia

Energy pyramid- a diagram that compares the energy used by producers, primary consumers, and other trophic levels.

Habitat- includes all of the living and nonliving components of the environment in which an organism lives

Ecological niche- how a species lives within its habitat or the role that it plays within the habitat

Competitive exclusion-states that when two species are competing for the same resources, one species will be better

suited to the niche, and the other species will either be pushed into another niche or will become extinct.

Ecological equivalent- species that occupy similar niches but live in different geographical regions.

Symbiosis- a close ecological relationship between two or more organisms of different species.

Biology Condensed EOCT Study Guide Mrs. Silver

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Mutualism- is an interaction in which both organisms benefit.

Commensalism- is a relationship in which one organism benefits and the other organism neither benefits nor is harmed

Parasitism- a relationship in which one species benefits and the other is harmed.

Population density- a measurement of the number of individuals living in a

defined space. Population density = number of individuals divided by the area (units squared).

Survivorship curve- is a diagram that shows the number of organisms that survive

over time, starting from birth.

Type I survivorship curve- Most live to be old (Large mammals and humans)

Type II survivorship curve- Chance of dying is the same for all ages (birds, small

mammals and reptiles)

Type III survivorship curve- Only a few live to old age, most die at birth

(invertebrates, fish, amphibians, and plants)

Carrying capacity- the maximum number of individuals of a particular species that the environment can support.

Density Dependent Limiting Factors- limiting factors for population that are affected by the population density

(competition, predation, parasitism, and disease).

Density Independent Limiting Factors- limiting factors for population that does not depend on the density of

individuals in the area (unusual weather, natural disasters-volcanoes, hurricanes, flooding or human activities)

Succession- a sequence of changes that recreates a damaged community or creates a new community in an area that was

not inhabited before.

Primary Succession- begins on bare rock (after volcano)

Pioneer species- the first organisms that move into an area

Secondary Succession- the regrowth of a damaged ecosystem in which the soil is still intact.

Nonrenewable resource- natural resource that is used more quickly than it can be formed.

Renewable resource- resource that replenishes itself quickly enough so that it will not be used faster than it can be

produced

Ecological footprint- amount of land necessary to produce and maintain enough food, water, shelter, energy, and waste.

Pollution- anything that is added to the environment and has a negative effect on the environment or its organisms.

Smog- air pollution in which gases released from burning fossil fuels form a fog when they react with sunlight.

Particulate- microscopic bits of dust, metal, and unburned fuel produced by industrial processes.

Acid rain- precipitation produced when pollutants in the atmosphere cause the pH of rain to decrease.

Greenhouse effect- normal warming effect produced when gases, such as carbon dioxide and methane, trap heat in Earth’s

atmosphere.

Global warming- worldwide trend of increasing average temperatures.

Indicator species- species whose presence in an ecosystem gives clues about the condition of that ecosystem.

Biomagnification- condition of toxic substances being more concentrated in tissues of organisms higher on the food chain

than ones lower in the food chain.

Habitat fragmentation- process by which part of an organism’s preferred habitat range becomes inaccessible

Introduced species- species that is not native and was brought to an area as a result of human activities

Sustainable development- practice of not using natural resources more quickly than they can be replenished.

Umbrella species- species whose being protected under the Endangered Species Act leads to the preservation of its habitat

and all of the other organisms in its community.

Relationships among organisms, populations, communities, ecosystems, and biomes Ecology is the scientific study of the interactions between living things and their environment.

Ecologist is a scientist who studies ecology.

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Biosphere includes all organisms and the environments in which they live

Biotic factors the living organisms in an ecosystem Plants Climate, Animals Light, Bacteria Soil Water

Abiotic Factors nonliving factors in an ecosystem

Niche: the role that a species plays in its community and includes not only what an organism eats, but also where it feeds and

how it affects the energy flow in an ecosystem.

Habitat: the place where the organism lives

Populations — A population includes all the organisms in the same species in a given area at one time who compete for

food, water, mates, and other resources. Ecologists study the relationships between populations and the environment, focusing on population size, density, and rate of growth.

Population density is the number of organisms living in a given area.

Many insects have juvenile stages that require very different resources from their adult counterparts. This minimizes competition within a population.

Communities — A community is a collection of populations that interact with each other in a

given area (does not live independently of other species) where balance is important. Ecologists study the interactions between the different populations in a community and the impact of additions to or losses of species within communities.

Growth Rate This change in population size is known as. A growth rate can be positive, negative,

or zero. If a population is provided with ideal conditions, it will

increase in number

Exponential Growth (J curve) As long as these ideal conditions continue, as the population grows larger the rate of

growth increases.

Logistic Growth (S curve) as the population increases, the resources that are available become limited, and the

growth of the population slows and begins to stabilize.

Carrying Capacity: the point at which the population becomes stable. 2 factors help stabilize it at that size.

o density-dependent (competition, predation, parasitism, and crowding/stress) and

o density-independent limiting factors (Weather, fires, droughts/floods, human activities):

Ecosystems — An ecosystem includes all biotic and abiotic factors within a given area. Factors that affect

that may disrupt an ecosystem. is the interactions among the populations in a community and the physical surroundings of the community.

Terrestrial ecosystems are those found on land.

Aquatic ecosystems are in either fresh or salt water.

Salt water ecosystems are also called marine ecosystems.

Biomes A group of ecosystems in same region with similar types of vegetation governed by similar climates

The ecosystem’s Energy flow (one direction) Sun: primary source of this energy is the

producers (plants and bacteria): harness the Sun’s energy to make energy-rich molecules

photosynthesis uses the Sun’s energy to convert carbon dioxide and water into glucose and oxygen.

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Glucose is the molecule that provides all organisms with a source of energy.

autotrophs, Producers are also called - meaning “self-feeding” because they do not need other organisms.

consumers animals need to eat other organisms to obtain energy and matter

heterotrophs, (consumers) meaning they need to feed on other organisms.

Decomposers are organisms that feed on dead bodies of animals and plants or on their waste products.

food chain a way for energy to move through an ecosystem. As sunlight hits the Earth, the energy flows first to primary

producers, then to consumers, and finally to decomposers.

food web more complex interconnected system of food chains

A FOOD CHAIN Sun grass mice hawk

A FOOD WEB Consumer Energy Source Example Herbivores eat plants deer Carnivores eat other animals lions Omnivores eat both plants and animals raccoon Decomposers break down dead organisms bacteria

Energy pyramids show how energy decreases at each succeeding level and the total

energy transfer is only about 10%. Not all the food consumed at each level is actually used for growth.

and explains why population sizes decrease through the trophic levels.

Secondary consumers 60 kcal/m2/yr

Primary Consumers 600 kcal/m2/yr

Producers 6,000 kcal/m2/yr

Recycling of Matter (flows both directions) Matter cannot be replenished in an ecosystem, unlike the energy from the Sun. Ex CO2

Relate environmental conditions to successional changes in ecosystems Succession is the natural change that takes place within a community of an ecosystem.

Primary succession is the gradual development of a new community where no

organisms have lived before. An example is the changes that take place after a volcanic eruption and the lava flow cools, hardens, and weather

Climax community Eventually, primary succession slows down and the community becomes stable.

Secondary succession occurs when a natural disaster or human activity partially destroys

a community where soil is already present and the different species replacing the pioneer species having less time to become a climax community. ---------------

Pollution is contamination of soil, water and air as a result of Human activities Renewable resource: natural resource that is replaced or replenished by natural processes

Nonrenewable resources are available only in limited amounts. Ex. Metals, minerals, topsoil, fossil fuels.

Air Pollution caused primarily by the burning of fossil fuels to produce electricity. Examples dust, smoke, ash, carbon monoxide, and

sulfur oxides. Smoke contains gases and particles. (Black Lung from coal dust)

Smog: A combination of smoke, gases, and fog and contains sulfur oxides reacts with water vapor in the atmosphere to

produce sulfuric acid.

90% decrease in energy as go up each level. Only 10% energy is left as go up each level

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Acid Rain: sulfuric acid falls to the ground damages crops, kills organisms in aquatic ecosystems, and erodes buildings

and monuments. leaches calcium and potassium from the soil, making the soil less fertile. Decreases PH in lake ecosystems causing excess acidity

Carbon Dioxide. Released when burning fossil fuels such as oil, coal, and natural gas

Greenhouse Effect. Gases in the atmosphere trap sun’s radiant energy and heats up Earth surface, radiating back

into the atmosphere where heat cannot escape.

Ozone Layer surrounds Earth and prevents lethal doses of sun’s UV radiation from reaching organisms. thinning

because of the release of CFCs (chlorofluorocarbons) into the atmosphere. CFCs are manufactured for refrigerator and air conditioner coolants and process of making Styrofoam.

Water Pollution

caused by contaminants from sewers, industries, farms, and homes,

Sewage, chemical wastes, fertilizer, and dirty wash water can enter water

Pollutants trickle down through the soil into underlying groundwater

Conservation Conserve Energy limiting the use of energy resources

increased use of public transportation and carpooling.

making homes and buildings more energy efficient.

Using alternative forms of energy (Solar energy and wind energy)

“Three Rs” reduce, reuse, and recycle. Reduce decreasing need of new materials

reuse or recycle materials instead of throwing them away.

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Plant Adaptations to the ability to survive stressful environmental conditions Seeds of many plants will go dormant in unfavorable conditions. Plants also have adaptations for reproduction (multiple pollinators) Trophoisms plants shift positions of roots, stems, leaves, and flowers in response to:

Tropism—a plant’s response to its environment

Geotropism—a plant’s response to gravity and causes the roots to grow downward and the stems to grow upward

Phototropism—a plant’s response to light (grow towards sun)

Thigmotropism—a plant’s response to touch (ivy grows up wall for support)

Hormones – chemicals used to control growth in response to environment.

Auxins regulates plant phototropism by stimulating the elongation of cells. High auxin concentrations promote fruit

growth. In fall, auxin decreases and fruit falls.

Gibberellins growth hormones that cause plants to grow taller and increase the

rate of seed germination and bud development. One signals that it is time to sprout.

Abscisic acid inhibits plant growth during times of stress, such as cold

temperatures or drought.

Ethylene – plant hormone causes the ripening of fruits

Animal Adaptations to the ability to survive stressful environmental conditions 1. Inherited Behavior An animal’s genetic composition determines how it responds to stimuli

Instincts take longer and may be a combination of behaviors. innate behavior. Includes automatic and instinctive

behaviors w/o thought. (reflex)

Territorial Behavior physical space that contains the breeding grounds, feeding area, shelter, or potential mates of

an animal – reduces competition and increases survival.

Aggression is another behavior exhibited by animals to fend off predators and competitors . same species will not

usually fight to the death with weaker animal submitting

Migration is the instinctive, seasonal movement of a species triggered by a hormone (some use Earth’s magnetic

field.)

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Hibernation is a condition in which the animal’s body temperature drops, oxygen consumption

decreases, and breathing rates decrease to just a few breaths per minute.

Estivation animals reduce the rate of their metabolism due to extreme heat, lack of food, or drought.

2. Learned behavior is a result of previous experiences that modifies animals’current behavior.

Habituation. It occurs when an animal is repeatedly given a stimulus that is not harmful and does not have a negative

impact on the animal.

Imprinting when an animal returns to the place of its birth to lay its eggs

Animal Adaptations for Defense Mechanical defense is incorporated into the physical structure of the organism.

Physical Structures such as claws, sharp ivory tusks, stingers, and shells.

Camouflage involves colors and patterns that enable the organism to blend into its environment

Cryptic coloration organism has the same color or pattern as its background. Ex. tree frogs

Disruptive coloration an organism’s silhouette is broken up by color patterns.

Countershading is when an organism is two-toned reducing visual cues to predators.

Chemical defense occurs when the animal produces stinging sensations, paralysis, poisoning, or just a bad taste.

Neurotoxins in their tissues that attack the nervous system of their attackers

Poisons and Venoms used by snakes, toads and stinging bees and wasps.

Use other species’ chemical defenses Ex. monarch butterfly eats milkweed (poisonous to vertebrates)

Chemical compounds in plants that taste bad, or sap that is an irritant/poison.

Nutrient exclusion. aren’t worth eating because they are lacking a sufficient amount of nutrients.

Behavior – anything an animal does in response to stimuli in its environment.

Stimulus- something that causes a physiological response

Inherited behavior- also known as innate behavior, meaning that an animal’s genetic composition determines how it

responds to stimuli.

Innate behavior- an animal’s genetic composition determines how it responds to stimuli. Includes both automatic

responses and instinctive behaviors.

Reflex –simple behaviors or automatic responses that require little or no thinking at all (blinking at bright light).

Instincts –a complex pattern of innate behaviors (explained in handout listed above)

Imprinting- process by which a newborn animal quickly learns to recognize another animal, such as a parent.

Imitation- process by which an organism learns a behavior by observing other individuals.

Territorial Behavior- defending an animal’s territory or space.

Migration- instinctive, seasonal movement of a species to a better suited environment.

Pheromones – are chemicals released by an animal that affect the behavior of other individuals.

Hibernation- a condition in which an animal’s body temperature drops, oxygen consumption decreases, and breathing rates

decrease

Estivation – condition in which animals reduce the rate of their metabolism due to extreme heat, lack of food, or long

periods of drought.

Learned behavior – a result of previous experiences of an animal that modifies their current behavior.

Habituation – a learned behavior that occurs when an animal is repeatedly given a stimulus that is not harmful or does not

have a negative impact on the animal. (Deer coming close to food without fear of people, etc.)

Mechanical defense – physical structures that protect an animal (thorns, spines, stiff hairs, teeth, quills).

Chemical defense –chemicals produced by an animal for defense (toxins, poisons, venoms, chemical to make plants taste

bad, etc.)

Camouflage – colors or patterns that enable an organism to blend into is environment or appear to be something that it is

not.

Cryptic coloration – when an organism has the same color or pattern as its background.

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Disruptive coloration – when an organism’s silhouette is broken up by color patterns. It is a way of confusing the eye. It

breaks up the solid outline of an animal’s body so that it is harder to see and recognize. (leopard, tiger, zebra)

Countershading – when an organism is two-toned. (Ocean fish, dark on top, light on bottom).

Nutrient exclusion – some plants are not worth eating as they are lacking in nutrients.

Gibbberellins – plant hormones that cause plants to grow taller

Auxin – plant hormone that regulates phototropism by elongating (making longer) cells on the shaded side of the plant

Abscisic acid - plant hormone that inhibits plant growth and cell division during times of stress (cold temperatures or

drought).

Plant pollination – can happen by wind, insects, birds, or other animals

Seed dormancy – ability of seeds to survive drought

Plant dormancy – ability of plants to survive drought by modifying roots and stems into storage organs or dropping leaves

Cytokinins – plant hormone that affects cell growth (stimulates cytokinesis in cell division)

Ethylene – plant hormone causes the ripening of fruits

Hormones – compounds such as gibberellins, auxins, and abscisic acid which control plant responses

Geotropism or Gravitropism – growth of a plant in response to gravity

Phototropism – growth of a plant in response to light

Thigmotropism – growth of a plant in response to touch

CELLS

Cell membrane Regulates what enters and leaves the cell and provides support

Cell wall A rigid covering of a plant cell made of cellulose

Chlorophyll A green pigment in chloroplasts that traps the energy in sunlight

Chloroplast An organelle in a plant cell that uses energy from sunlight to make food in the photosynthesis process

Chromatin Granular material in the nucleus made up of DNA bound to protein

Chromosomes threadlike genetic carrying structures formed from chromatin during cell division

Cilium Short hairlike projection producing movement in many cells

Cytoplasm Jellylike fluid that flows around inside the cell and contains organelles, but not including the nucleus

Cytoskeleton Network of protein filaments that maintains shape and aids in cell movement

DNA Deoxyribonucleic acid that makes up all hereditary information of the cell

Endoplasmic reticulum A system of double membranes on which chemical reactions take place.

Enzymes Are used in the Golgi apparatus to attach carbohydrates and lipids to proteins

Eukaryotes cells that contain a nucleus; plant and animals cells

Flagellum Whiplike structure on some cells that is used for movement

Golgi apparatus (Golgi body)

Membranes in the cell in which enzymes attach carbohydrates and lipids to proteins

Lipid bilayer Double-layered sheet that forms the core of nearly all cell membranes

Lysosome Filled with enzymes to break down certain materials in the cell

Microfilaments Long, thin fiber that functions in the movement and support of the cell

Microtubule Maintains cell shape and serves as a track along which organelles are moved

Mitochondrion/ Mitochondria

Cell organelle that releases energy from stored food molecules (break down substances to produce energy for the cell)

Nuclear membrane/ envelope

Membrane (phospholipid bilayer) that surrounds the nucleus of a cell

Nucleolus Small, dense region within most nuclei in which assembly of ribosomes begins

Nucleus In some cells: contains the genetic material (DNA) and controls activities

Organelles Tiny structures inside the cell that each perform specific jobs for the cell

Peroxisome Enzymatic activities associated with conversion of hydrogen peroxide to water

Photosynthesis Process by which plants use light energy to power chemical reactions

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Prokaryotes Cell that lacks a nucleus; bacteria

Ribosome Where proteins are assembled; made of RNA and protein (can be attached to the rough ER or float in the cytoplasm)

RNA Ribonucleic acid; single stranded nucleic acid that contains the sugar ribose

Rough endoplastic

reticulum

Has ribosomes on its surface; where proteins may be chemically modified

Smooth endoplastic reticulum

Does not have ribosomes on surface; involved in synthesis of lipids

Thylakoids Saclike body in chloroplasts made of photosynthetic membranes

Vacuoles Organelle that stores material such as water, salts, proteins, & carbohydrates

Differentiate between prokaryotic and eukaryotic cells PROKARYOTES: Single-celled organisms that lack internal structures surrounded by membranes that lack a nucleus.

Examples: Bacteria

EUKARYOTES: Single- & multi-cellular organisms - cells containing internal, membrane-bound structures and have a

true nucleus containing the cell’s DNA. Examples: Plants, Animals, fungi, & protists

Organelles and their functions: Nucleus: contains DNA, which controls cellular function

Chloroplasts: capture solar energy for photosynthesis

Golgi bodies: modify, sort, and ship proteins and lipids

Mitochondria: ATP formation

Ribosomes: synthesis of polypeptide chains, proteins

Cell membranes: flexible boundary, controls the movement of materials in and out of the cell and maintains a

chemical balance within the cell.

Cell wall: inflexible boundary that is thicker than the cell membrane that protects the cell and gives the cell its shape.

Found only in Plants, fungi, most bacteria, and a few protists

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The importance of homeostasis Homeostasis is the cell’s balance between materials entering and exiting the cell using cell membrane. The cell controls

proper internal concentrations of water, glucose, and other nutrients, while eliminating cellular wastes.

Selective permeability is the property of the cell membrane that allows certain materials to

pass through the cell while keeping others out allowing one cell to perform multiple functions. Ex Nerve cell response to chemical in blood (doesn’t affect other cells)

Passive transport is the movement of materials across the cell membrane without the use of the cell’s energy. Different

types of passive transport are shown in the box below.

Diffusion: the movement of substances high to low concentration.

Osmosis: the diffusion of water molecules from high to low concentration

Facilitated transport (Facilitated diffusion): occurs when a carrier molecule embedded in the cell membrane

transports a substance across the membrane by means of diffusion

Active transport: a process that drives large molecules across the cell membrane from a region of lower concentration to a

region of higher concentration – requires Energy

Endocytosis: cell surrounds and takes in material from its environment

Exocytosis: cell surrounds and removes materials from inside the cell

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Solute The minor component in a solution, solute is what is dissolved in the solvent. If I dissolve Kool-Aid in a pitcher of water, the Kool-Aid powder or packet would be the solute.

Active transport Material moves from lower concentration to greater concentration

Passive Transport Passive transport is a movement of ions and other atomic or molecular substances across cell

membranes without need of energy input. Unlike active transport, it does not require an input of

cellular energy. Includes: osmosis, diffusion, and facilitated diffusion (use of protein channel

embedded in cell membrane).

Carbohydrate chains (in cell membrane)

Act like chemical identification cards, allowing cells to identify other cells

Carbohydrates (in cell membrane)

Form chains that are attached to proteins in the lipid bilayer

Cell membrane Regulates what enters and leaves the cell and provides support. These membranes are composed primarily of phospholipids and proteins and are typically described as phospholipid bi-layers.

Diffusion Molecules move from greater concentration to lower concentration

Endocytosis Taking material into the cell by infoldings, or pockets of the cell membrane

Exocytosis The membrane of the vacuole fuses with the cell membrane, forcing material out

Facilitated diffusion Movement of molecules across cell membranes through protein channels

Lipid bilayer Double-layered sheet that forms the core of nearly all cell membranes

Lipids Macromolecule made from carbon & hydrogen, includes: fats, oils, and waxes

Osmosis Diffusion of water through a selectively permeable membrane

Osmotic pressure Pressure exerted on the hypertonic side of a selectively permeable membrane

Phagocytosis Extensions of cytoplasm surround and engulf large particles and take into cell

Protein channels Many membranes have these to allow molecules to cross the membrane

Proteins Form channels and pumps that help to move material across the membrane

Hypertonic A hypertonic cell environment is one in with a higher concentration of solutes than the cytoplasm. In a hypertonic environment (or when a cell is placed in a hypertonic solution), osmosis causes water to flow out of the cell.

Hypotonic A hypotonic cell environment is one with a lower concentration of solutes than the cytoplasm. In a hypotonic environment (or when a cell is placed in a hypotonic solution), osmosis causes water to flow into the cell.

Isotonic An isotonic solution refers to two solutions having the same osmotic pressure across a semipermeable membrane. This state allows for the free movement of water across the membrane without changing the concentration of solutes on either side. There is an equilibrium reached creating the same concentration of solute inside the cell as is outside the cell.

Transport Across Cell Membranes Concepts

Passive Transport- There are examples where molecules move across a membrane from a region of high concentration to a

region of low concentration, (molecules moving down a concentration gradient as if going downhill) and no energy is required. This is called passive transport. This type of transport may occur by diffusion, facilitated diffusion (protein embedded in cell membrane allows a tunnel for diffusion to occur) and osmosis (movement of water) across the membrane.

Active Transport- There are also examples where molecules move across a membrane from a region of low concentration

to a region of high concentration (molecules moving against a concentration gradient as if going uphill), and this requires a source of energy to "pump" the molecules uphill in concentration. Such processes are called active transport. It can also occur when a vesicle attaches to the cell membrane from the inside and then opens to form a pocket, expelling its contents to the outside. This is called exocytosis. The cell membrane may also envelope something on the outside and surround it, taking it into the cell. This is called endocytosis or phagocytosis (when large particles are engulfed by the cell). Anytime energy is required for molecules to pass across a cell membrane it is called active transport.

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Tonicity Concepts

Hypertonic- The term hypertonic can refer to solute concentration inside or outside of the cell. Wherever the location, if

there is MORE solute concentration in a given location (inside or outside the cell) then it is considered hypertonic. If there is MORE solute concentration inside the cell, then the cell is hypertonic compared to the surrounding solution. If there is MORE solute concentration outside the cell (in the solution), then the solution that the cell is in is hypertonic compared to the solution inside the cell.

Hypotonic- The term hypotonic can refer to solute concentration inside or outside of the cell. Wherever the location, if there

is LESS solute concentration in a given location (inside or outside the cell) then it is considered hypotonic. If there is LESS solute concentration inside the cell, then the cell is hypotonic compared to the surrounding solution. If there is LESS solute concentration outside the cell (in the solution), then the solution that the cell is in is hypotonic compared to the solution inside the cell.

Water Movement TO DO WELL ON THIS TEST it is EXTREMELY important to grasp the concept that water will always move in the direction of “MORE SOLUTE” thus always seeming to try to dilute (or water down and make less concentrated) a higher solute concentration wherever it might be (inside or outside of the cell).

If there is more solute concentration outside of the cell (making the solution the cell is placed in hypertonic compared

to the cell which is hypotonic), water will move in the direction of MORE SOLUTE and move out of the cell and into the

hypertonic solution causing the cell to shrink or shrivel.

If there is MORE SOLUTE concentration inside the cell making the cell hypertonic compared to the solution it is in

(solution being hypotonic compared to the hypertonic cell), water will move into the cell (diluting the higher solute

concentration inside the cell) causing it to swell or even possibly explode or burst.

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ENZYMES

3 characteristics of enzymes 1. Enzymes do not create processes that would not take place on their own. (Just makes reactions faster) 2. Enzymes are not permanently altered or used up in reactions. 3. Each enzyme catalyzes only one specific type of reaction, but can do multiple times

Enzymes are catalytic molecules -they speed up specific reactions

without being used up in the reaction. Enzymes are proteins.

Substrates are molecules that a specific enzyme can chemically

recognize and bind

Products are Substrates undergo chemical changes to form new

substances

active site area of the enzyme that each substrate fits into

activation energy is amount of energy used by substrate molecules

to reach the transition state.

Enzymes:

Carbonic anhydrase speeds up the process by which CO2 leaves cells and enters the bloodstream so it can be

removed from the body.

lipase is produced by the pancreas and functions in the digestion of lipids.

RNA polymerase is an enzyme that facilitates the process of transcription.

Some diseases, such as Tay-Sachs and phenylketonuria, occur when the body fails to make a critical enzyme.

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Understand the characteristics of the four major macromolecules

Carbohydrates provides useable energy for cell

simple sugar with the ratio of carbon, hydrogen, and oxygen atoms is 1:2:1

3 classes of carbohydrates: monosaccharides, oligosaccharides, and polysaccharides.

Examples Glucose, sucrose, starch, and cellulose (plants only to make cell walls)

Lipids organic compounds that have more (C-H) bonds and fewer O atoms than carbohydrates.

commonly called fats and oils - They are insoluble in H2O (water)

used by cells for long-term energy storage (and cell membranes)

Substrate

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Proteins chains of amino acids made of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur.

important in muscle contraction, transporting oxygen in the blood, and the immune system.

Examples :Collagen, enzymes, hemoglobin, insulin, and antibodies

Nucleic Acids complex macromolecules that store and transmit genetic information in cells in a code.

made up of 4 nucleotides (a small organic compound that consists of a five-carbon sugar, a nitrogen-containing base, and a phosphate group)

Examples include ATP, NAD+, NADP+, DNA, and RNA.

Carbohydrates Macromolecule or biomolecule composed of carbon, hydrogen, and oxygen; includes sugars and starches

Carbohydrate Monomer Monosaccharides “simple sugars”

Carbohydrate Types Monosaccharides (1 sugar – glucose) Disaccharides (2 sugars – sucrose) Polysaccharides (many sugars – starch)

Carbohydrates Function Main energy source (quick energy source), main fuel for cells, structures, provides energy for the process of respiration

Carbohydrates Found In Pasta, cereals, sugars, bread, potatoes, fruit (fructose- fruit sugar), veggies, sodas, cellulose

Lipids Nonpolar molecule composed of carbon, hydrogen, and oxygen; includes fats and oils

Lipids Monomer fatty acids

Lipid Types triglycerides, waxes, fats, oils

Lipid Function energy storage, protection: waterproofing and insulation, cell membrane and provides solubility for some vitamins/ minerals

Lipids Found In oils, butter, cheese, shortening, red meat, cheese, dairy products.

Protein Polymer composed of amino acids linked by peptide bonds; folds into a particular structure depending on bonds between amino acids.

Protein Monomer amino acids

Protein Types Form polypeptides such as: Antibodies, Enzymes, Hormones,

Protein Function Control rates of reactions, form muscle and bones, move things in and out of the cell, fight disease

Proteins Found In muscle meats (any muscle from an animal), muscle (heart, skeletal), meats, eggs, beans, nuts, grains, legumes (legumes include: peas, beans, alfalfa, and peanuts), seafood, poultry (chicken), seeds, soy, also found in hormones like insulin, and enzymes like amylase, lactase

Nucleic Acids Polymer of nucleotides; the genetic material of organisms

Nucleic Acid Monomer Nucleotides

Nucleic Acid Types DNA (Deoxyribonucleic acid) and RNA (Ribonucleic acid)

Nucleic Acid Function Store and transmit genetic information; information to produce all cell parts and materials thru DNA and RNA

Nucleic Acid Found in Found in all living cells

Fatty Acids Hydrocarbon chain often bonded to glycerol in a lipid

Amino Acids Molecule that makes up proteins; composed of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur

Chemical Reactions Process by which substances change into different substances through the breaking and forming of chemical bonds

Reactants Substance that is changed by a chemical reaction

Products Substance formed by a chemical reaction

Catalyst Substance that decreases activation energy and increases reaction rate in a chemical reaction

Enzymes Protein that catalyzes chemical reactions for organisms

Substrates Reactant in a chemical reaction upon which an enzyme acts

----------------------

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Comprehend the importance of osmosis and diffusion on life processes Diffusion: The movement of dissolved molecules in a fluid or gas from a region of

high to low concentration.

Osmosis: The diffusion of water molecules across a semipermeable membrane from higher water to lower water

concentration. 2 methods – direct or water channels in the cell membrane called aquaporins.

ORGANISMS

taxonomy The science of classifying and naming organisms.

taxon Level within the Linnaean system of classification: (kingdom, phylum, class, order, family, genus, or species)

binomial nomenclature

Naming system in which each species is given a two-part scientific name (genus and species) using Latin words and written in italics.

genus First name in binomial nomenclature; the second-most specific taxon in the Linnaean classification system that includes one or more physically similar species, which we thought to be closely related.

phylogeny Evolutionary history of a group of related species

cladistics Method of organizing species by evolutionary relationships in which species are grouped according to the order that they diverged from their ancestral line.

cladogram Diagram that displays proposed evolutionary relationships among a group of species.

derived character Trait that differs in structure or function from that found in the ancestral line for a group of species; used in constructing cladograms.

molecular clock Theoretical clock that uses the rate of mutation to measure evolutionary time.

mitochondrial DNA DNA found only in mitochondria, often used as a molecular clock

ribosomal RNA RNA that is in the ribosome and guides the translation of mRNA into a protein; also used as a molecular clock

Bacteria One of the three domains of life, containing single-celled prokaryotes in the kingdom Bacteria

Archaea One of the three domains of life, containing single-celled prokaryotes in the kingdom Archaea.

Eukarya One of the three domains of life, contains all eukaryotes in kingdoms Protista, Plantae, Fungi, and Animalia.

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DIFFERENCE IN CLADOGRAM AND PHYLOGENETIC TREE

Both cladograms and phylogenetic trees show the relationships between organisms.

Both cladograms and phylogenetic trees are drawn using lines to show relationships.

The difference is that the length of the lines in a phylogenetic tree represents time while the lines in cladograms are the same length.

Explain the flow of energy needed by all organisms to carry out life processes Cells Use Energy: make new molecules (enzymes too), build cell organelles/ membranes & maintain homeostasis.

ATP Adenosine triphosphate- high energy molecule that contains, within its bonds, energy that cells

can use.

ADP Adenosine diphosphate- low-energy molecule that can be converted to ATP

Chemosynthesis Process by which ATP is synthesized by using chemicals as an energy source instead of light.

Photosynthesis Process by which light energy is converted to chemical energy; produces sugar and oxygen

from carbon dioxide and water

Chlorophyll Light-absorbing pigment molecule in photosynthetic organisms

Thylakoid Membrane-bound structure within chloroplasts that contains chlorophyll and other light-absorbing pigments used in the light-dependent reactions of photosynthesis

Light-dependent reactions Part of photosynthesis that absorbs energy from sunlight and transfers energy to the light-independent reactions.

Light-independent reactions Part of photosynthesis that uses energy absorbed during the light-dependent reactions to synthesize carbohydrates.

Photosystem Series of light-absorbing pigments and proteins that capture and transfer energy in the

Phylogenetic Tree

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thylakoid membrane.

Electron transport chain Series of proteins in the thylakoid and mitochondrial membranes that aid in converting ADP to ATP by transferring electrons.

ATP synthase Enzyme that catalyzes the reaction that adds a high-energy phosphate group to ADP to form ATP

Calvin Cycle Process by which a photosynthetic organism uses energy to synthesize simple sugars from CO2

Cellular respiration Process of producing ATP by breaking down carbon-based molecules when oxygen is present.

Aerobic Process that requires oxygen to occur

Glycolysis Anaerobic process in which glucose is broken down into two molecules of pyruvate and two net ATP are produced

Anaerobic Process that does NOT require oxygen to occur

Krebs cycle Process during cellular respiration that breaks down a carbon molecule to produce molecules that are used in the electron transport chain

Autotrophs: organisms that can manufacture their own energy-providing food molecules.

Chlorophyll, which is the molecule in the chloroplasts of plants that absorbs energy from sunlight.

chloroplasts that contain the chlorophyll and where light reaction occurs.

stroma a gel-like matrix inside chloroplast containing ribosomes, DNA, and material for carbohydrate synthesis

grana stacks of flattened sacs containing interconnected thylakoids

PHOTOSYNTHESIS

Photosynthesis: autotrophic organisms trap energy from the Sun and use this energy to build carbohydrates. This trapped

energy converts the inorganic raw materials CO2 and H2O to carbohydrates and O2. Equation is:

6CO2 + 6H2O + energy from sunlight → C6H12O6 + 6O2

Photosynthesis takes place in two parts of chloroplasts (grana (thylakoids) and stroma). Chlorophyll is a molecule that absorbs light energy. In plants, chlorophyll is found in organelles called chloroplasts.

1st phase of photosynthesis – The Light Reaction (ENERGY) reactions split water molecules, providing hydrogen and an energy source for the Calvin cycle. Oxygen is given off. The energy from sunlight causes electrons in chlorophyll to gain energy and pass the energy to other molecules which are used to make ATP.

Electrons, along with hydrogen ions from water, are added to NADP+ to produce NADPH.

NADP+ is the oxidized form (the form that lacks electrons)

NADPH is the reduced form (the

form that has electrons) of the same molecule and carries energy to the Calvin cycle.

PART ONE: The light-

dependent reactions

captures energy from

sunlight.

take place in thylakoids

water and sunlight are needed

chlorophyll absorbs energy

energy is transferred along thylakoid

membrane then to light-independent

reactions

oxygen is released

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PART TWO: The light-independent reaction (does not require light).

• The light-independent reactions make sugars. • take place in stroma • needs carbon dioxide from atmosphere • use energy to build a sugar in a cycle of chemical reactions

2nd phase of Photosynthesis - The Calvin Cycle form simple sugars using CO2 and H from water and occurs inside chloroplast’s stroma

Carbon dioxide from the air combines with hydrogen from the light reaction to form simple sugars.

Used to make complex sugars, starches, and cellulose.

enzyme adds the carbon atom of carbon dioxide to a 5-carbon molecule. carbon fixation(carbon is now fixed)

Creates a 6-carbon molecule and immediately splits into two 3-carbon molecules.

two 3-carbon molecules formed are called PGA molecules (phosphoglyceric acid). These molecules are converted into two 3-carbon sugars, PGAL (phosphoglyceraldehyde), using the hydrogens of NADPH + H+ and energy from ATP.

Understanding ATP /ADP (nucleotides) ATP: adenosine triphosphate: special molecule that stores and releases the energy

ADP: adenosine diphosphate: inorganic phosphate created when ATP releases stored energy

Phosphorylation: process where the terminal phosphate group of an ATP molecule can be transferred to a variety of other

compounds using an enzyme.

bioluminescence:. The light produced by lightening bugs that is a result of a chemical reaction that is powered by the

breakdown of ATP.

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ATP transfers energy from the breakdown of food molecules to cell functions.

Energy is released when a phosphate group is removed from an ATP molecule.

ADP is changed into ATP when a phosphate group is added to ADP.

Cellular Respiration- Organisms break down carbon-based molecules to produce ATP.

Carbohydrates are the molecules most commonly broken down to make ATP.

o not stored in large amounts

o up to 36 ATP from one glucose molecule

Fats store the most energy.

o 80 percent of the energy in your body

o about 146 ATP from a triglyceride

Proteins are least likely to be broken down to make ATP.

o amino acids not usually needed for energy

o about the same amount of energy as a carbohydrate

CELLULAR RESPIRATION Cellular respiration process of breaking down carbohydrates for ATP into simple sugars (glucose). Equation is C6H12O6 + 6O2 → 6CO2 + 6H2O + energy

GLYCOLYSIS Glycolysis is needed for cellular respiration. (Is the making of ATP by splitting one glucose molecule into 2 pyruvate molecules.) Glycolysis takes place in the cell’s cytoplasm and is an anaerobic (without oxygen) process.

glucose enters a cell by active transport. Organisms get energy from carbohydrates

makes ATP when glucose is broken down by enzymes into pyruvic acid.

produces 2 molecules of ATP.

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The process of cellular respiration releases carbon dioxide and water. Glycolysis Krebs Cycle Electron Transport Chain Glucose → Pyruvic Acid → NADH + FADH2 → CO2 and H2O and 32-38 ATP

Location: cytoplasm Anaerobic Process: No oxygen required Input: glucose Output: pyruvate ATP produced: 2 ATP

KREBS CYCLE

The Krebs Cycle in Summary (part 1 of cellular respiration)

The Krebs cycle breaks down citric acid and transfers energy to the electron transport chain. Takes place in mitochondria & breaks down the products of glycolysis, releasing CO2 & 2 ATP. Move high energy electrons to molecules for the electron transport chain.

Location: mitochondria matrix Inputs: oxygen and pyruvate ATP produced: 2ATP Output: CO2

Electron Transport Chain (last part of cellular respiration)– series of proteins in the mitochondria that convert ADP to make 34 (32-38) ATP by transferring electrons.

Location: mitochondria matrix Output: H2O ATP Produced: 32-36 ATP Proton Pump: ATP Synthase = Active transport Pump ADP changed to ATP -------------------------

The Six Kingdoms As scientists discovered evolutionary relationships among species, the classification system changed or was modified to fit these new discoveries. Comparisons of DNA sequences and similarities in proteins have helped to identify relationships between different organisms.

Eubacteria: ancient prokaryotic organisms found in extreme environs (Moneran) Archaebacteria: prokaryotic organisms such as true bacteria (Moneran)

Protists: uni/multicelluar eukaryotic organisms in moist environ & lack complex organ systems Fungi: uni/multicelluar heterotrophic eukaryotes that do not move and absorb nutrients from decomposing dead

organisms/waste

Plants: photosynthetic multi-cellular eukaryotes w/ cellulose cell walls and tissues that have been organized into organs and

organ systems. Animals: multi-cellular eukaryotic consumers that do not have cell walls. Their tissues have been organized into complex

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organ systems such as the nervous, muscle and digestive systems. -------------------- Taxonomy is the branch of biology dealing with the grouping and naming of organisms. Taxonomist studies taxonomy by comparing the internal and external structures, analyzing the chemical makeup, and

comparing the evolutionary relationships of species.

7 Levels of Classification is the grouping of objects based on similarities:

Kingdom All organisms are grouped into kingdoms based on genetic and anatomic similarities. Phylum organisms are subdivided again based on evolutionary traits.

Class based upon shared physical characteristics.

Order based on a more specific and limited set of characteristics

Family

Genus

Species: the same “kind” of animal and can reproduce with other members of the same species ---------------

Viruses & Bacteria

virus Infectious particle made only of a strand of either DNA or RNA surrounded by a protein coat

pathogen Agent that causes disease

capsid Protein shell that surrounds a virus.

bacteriophage Virus that infects bacteria

lytic infection Infectious pathway of a virus in which host cells are destroyed

lysogenic infection Infectious pathway of a virus in which host cells are NOT immediately destroyed

prophage DNA of a bacteriophage inserted into a host cell’s DNA

epidemic Rapid outbreak of a disease that affects many people

vaccine Substance that stimulates an immune response, producing acquired immunity without illness or infection.

plasmid Circular piece of genetic material found in bacteria that can replicate separately from the DNA of the main chromosome.

flagellum (plural: flagella) whiplike structure outside of a cell that is used for movement.

conjugation Process by which a prokaryote transfers part of its chromosome to another prokaryote

endospore Prokaryotic cell with a thick, protective wall surrounding its DNA

toxin Poison released by an organism

antibiotic Chemical that kills or slows the growth of bacteria

infectious particles made of a protein shell called a capsid, which contains either DNA or RNA.

some viruses have an outer membranous envelope (from host cell membrane ) covering the capsid and contain both viral and host cell lipids and proteins.

not living organisms - they are not cells and they cannot reproduce outside of a host cell.

must infect a living cell, a host, in order to reproduce their viral genetic material and to make new viral proteins.

Like living organisms, viruses contain genetic material (either DNA or RNA), can reproduce, respond to their environment, and evolve. Unlike living organisms, viruses are not cells, do not contain organelles, and are unable to reproduce without a host cell.

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GENETICS Carrier Organism whose genome contains a gene for a certain trait or disease that is not expressed in the

organism’s phenotype. A genetic carrier (or just carrier), is a person or other organism that has

inherited a recessive allele for a genetic trait or mutation but does not display that trait or show

symptoms of the disease. An example of a carrier would be a person with the genotype Bb. They

carry the little “b” recessive gene, but do not show this trait because they have the dominant gene

“B” that is expressed in their phenotype. In other words they carry the gene for blue eyes, but

actually have brown eyes because of their genotype Bb. They could still pass the recessive gene “b”

to their offspring.

Sex-linked gene Gene that is located on a sex chromosome.

X Chromosome Inactivation

Process that occurs in female mammals in which one of the X chromosomes is randomly turned off

in each cell. As nearly all female mammals have two X chromosomes, X-inactivation prevents them

from having twice as many X chromosome gene products as males, who only possess a single copy of

the X chromosome (see dosage compensation). The choice of which X chromosome will be

inactivated is random in placental mammals such as humans, but once an X chromosome is

inactivated it will remain inactive throughout the lifetime of the cell and its descendants in the

organism. Unlike the random X-inactivation in placental mammals, inactivation in marsupials applies

exclusively to the paternally derived X chromosome.

Incomplete Dominance Heterozygous phenotype that is a blend of the two homozygous phenotypes. Pink roses are often the result of incomplete dominance. When red roses, which contain the dominant red allele, are mated with white roses, which is recessive, the offspring will be heterozygotes and will express a pink phenotype.

Codominance Codominance, is a situation in which both alleles are equally strong and both alleles are visible in the hybrid genotype. Codominance is a heterozygous genotype that equally expresses traits from both alleles. When two alleles for a trait are equally expressed with neither being recessive or dominant, it creates codominance. Examples of codominance include a person with type AB blood, which means that both the A allele and the B allele are equally expressed. Another example of codominance is found in chickens. When white chickens are crossed with black chickens, the result is not a grey chicken, but a chicken with both black and white feathers.

Polygenic trait Trait that is produced by two or more genes. Polygenic traits are those traits that are controlled by more than one gene. Such traits may even be controlled by genes located on entirely different chromosomes. Human height, eye and hair color are examples of polygenic traits. Skin color is another polygenic trait for humans and a variety of other animals.

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Locus (plural, Loci) Locus (genetics), the position of a gene, or other significant sequence, on a chromosome.

Linkage map Diagram that shows the relative locations of genes on a chromosome. Genes whose loci are nearer to each other are less likely to be separated onto different chromatids during chromosomal crossover, and are therefore said to be genetically linked. In other words, the nearer two genes are on a chromosome, the lower is the chance of a swap occurring between them, and the more likely they are to be inherited together. Linkage Map Example Below:

Pedigree Chart of the phenotypes and genotypes in a family that is used to determine whether an individual is

a carrier of a recessive allele. Pedigree chart, a document to record ancestry, used by genealogists in study of human family lines, and in selective breeding of animals

How to read a pedigree chart

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Example of a Pedigree Chart

Karyotype Image of all of the chromosomes in a cell. Karyotype is a test to identify and evaluate the size, shape,

and number of chromosomes in a sample of body cells. Extra or missing chromosomes, or abnormal positions of chromosome pieces, can cause problems with a person's growth, development, and body functions.

Epistatic Gene (Epistasis)

Epistatic gene, in genetics, a gene that determines whether or not a trait will be expressed. The system of genes that determines skin color in man, for example, is independent of the gene responsible for albinism (lack of pigment) or the development of skin color. This gene is an epistatic gene. When the albino condition occurs, the genes that determine skin color are present but not expressed. Condition of having an epistatic gene is called epistasis. Epistasis is the interaction between genes at different loci. Epistasis is the suppression of a gene by the effect of an unrelated gene.

Example of Karyotype

Trait Characteristic that is inherited. Trait

Genetics Study of the heredity patterns and variation of organisms.

Purebred Type of organism whose ancestors are genetically uniform. Purebred - Organism with identical alleles/genes for a trait (homozygous).

Cross Mating of two organisms

Law of independent assortment

Mendel’s second law, stating that allele pairs separate from one another during gamete formation.

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Law of segregation Mendel’s first law stating that: 1. Organisms inherit 2 copies of genes, one from each parent 2. Organisms donate only one copy of each gene in their gametes because the genes separate

during gamete formation.

Trait Characteristic that is inherited.

What is the difference in Law of independent assortment and Law of segregation?

1. Mendel's law of Segregation states that two alleles for a particular gene segregate (or separate) from each other during gamete formation and end up in different gametes.

2. Mendel's law of Independent Assortment states that each pair of alleles segregates independently of other pairs of alleles during gamete formation. In other words, traits are transmitted to offspring independently of one another.

For Example: Let's pretend I only have genes for hair color and eye color, one dominant and one recessive for each. We'll say that I have one blonde hair gene and one brown hair gene, and one blue eyes gene and one brown eyes gene.

The law of segregation says that when I make gametes (sperm or eggs), the alleles for my eye

color genes will separate. An egg may get the blue eye gene or the brown eye gene, but not both. Same for hair. Exactly one allele from each pair of alleles is found in each gamete (assuming there are no mistakes).

The law of independent assortment says that whether an egg gets the blue eyes gene or

brown eyes gene does not depend on whether it gets the brown hair gene or blonde hair gene. Therefore, brown hair + blue eyes, brown hair + brown eyes, blonde hair + blue eyes, and blonde hair + brown eyes are all possible. They are randomly assorted, not linked together in patterns.

Bacteriophage Virus that infects bacteria. A virus that is parasitic in bacteria; it uses the bacterium's machinery and energy to produce more phage until the bacterium is destroyed and phage is released to invade surrounding bacteria

Nucleotide Monomer (smallest unit) that forms DNA and has a phosphate group, a sugar, and a nitrogen-

containing base.

Double helix Model that compares the structure of DNA molecule, in which two strands wind around one another, to look like that of a twisted ladder.

Base pairing rules Rule that describes how nucleotides form bonds in DNA; adenine (A) always pairs with thymine

(T), and guanine (G) always bonds with cytosine (C).

Replication Process by which DNA is copies

DNA polymerase Enzyme that makes bonds between nucleotides, forming an identical strand of DNA during

replication. The function of DNA polymerase is to replicate, proofread and repair DNA

Central dogma Theory that states that, in cells, information only flows from DNA to RNA to proteins.

RNA Nucleic acid molecules that allows for the transmission of genetic information and protein

synthesis. It’s the message sent from the DNA in the nucleus to the ribosomes in the

cytoplasm to create a specific protein that it codes for.

Transcription Process of copying a nucleotide sequence of DNA to form a complementary strand of mRNA.

The creation of mRNA (messenger RNA) from DNA in the nucleus.

RNA polymerase Enzyme that catalyzes the synthesis (creation) of a complementary strand of RNA from a DNA

template. Enzyme that makes RNA from DNA.

Messenger RNA (mRNA)

Form of RNA that carries genetic information from the nucleus to the cytoplasm, where it serves

as a template for protein synthesis.

Ribosomal RNA (rRNA) RNA that is in the ribosome and guides the translation of mRNA into a protein; also used as a

molecular clock.

Molecular clock Theoretical clock that uses the rate of mutation to measure evolutionary time

Transfer RNA (tRNA) Form of RNA that brings amino acids to ribosomes during protein synthesis

Translation Process by which mRNA is decoded and a protein is produced

Codon Sequence of three nucleotides that codes for one amino acid

Stop codon Codon that signals to ribosomes to stop translation

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Start codon Codon that signals to ribosomes to begin translation; codes for the first amino acid in a protein

Anticodon Set of three nucleotides in a tRNA molecule that binds to a complementary mRNA codon during

translation

Promoter Section of DNA to which RNA polymerase binds, starting the transcription of mRNA

Operon Section of DNA that contains all of the code to begin transcription, regulate transcription, and

build a protein; includes a promotor, regulatory gene, and structural gene.

Exon Sequence of DNA that codes information for protein synthesis

Intron Segment of a gene that does not code for an amino acid

Mutation Change in the DNA sequence

Point mutation Mutation that involves a substitution of only one nucleotide

Frameshift mutation Mutation that involves the insertion or deletion of a nucleotide in the DNA sequence

Mutagen Agent that can induce or increase the frequency of mutation in organisms

Semi-conservative replication

During DNA replication, the two strands of nucleotides separate. Both strands then form the

template for free nucleotides to bind to to create the two identical daughter strands. Hence

each daughter strand has half of the DNA from the original strand and half newly-formed

DNA.

Chargaff’s Rule Chargaff's rules state that, as a result of how the DNA bases pair, the amount of adenine and

thymine are equal, and the amount of cytosine and guanine are equal

How to calculate percentages of DNA nucleotides.

Often, a percentage problem will reveal the percentages of some or one of the other bases. For

example, there may be 30 percent cytosine. From this information, you can determine that

there is 30 percent guanine, because the amount of cytosine and guanine is equal. Adding

30 percent and 30 percent gives you 60 percent (total amount of guanine and cytosine

combined). Subtracting 60 percent from 100 percent yields 40 percent (this is the percent

remaining for adenine and thymine to be). Dividing 40 percent by two gives you 20 percent.

Therefore, there is 20 percent thymine. Since the amounts of thymine and adenine are

equal, there is 20 percent adenine in the DNA strand.

Genetics: branch of biology that studies heredity, the passing on of characteristics, or traits, from parents to offspring.

DNA Nucleic acid DNA forms a complex biological polymer used for storing and transmitting information are made up of

smaller subunits Nucleotides are composed of deoxyribose, a phosphate group,& nitrogen.

Four nitrogen bases––adenine (A), guanine (G), cytosine (C), and thymine (T). (A-T), (G-C).

Structure of DNA DNA carries information in a triplet code and signal beginning or end. double helix nucleotides combine to form two ladder chains twisted with hydrogen bonds holds two strands of nucleotides together and the sides of the ladder are phosphate groups alternating with five-carbon sugars (deoxyribose)

DNA replication ability to make an exact copy of itself. Mitosis or meiosis. It uses an enzyme to break the hydrogen

bonds and “unzips” the two strands, which rebond as 2 copies

Eukaryotic cells, DNA is found inside the nucleus vs Prokaryotes cells whose DNA is attached to cell membrane or

free floating in the cytoplasm.

RNA Single strand of nucleotides, the sugar in RNA is ribose and the nitrogen- containing base uracil replaces the

thymine found in DNA. (U-A), (G-C).

Transcription RNA transfers the genetic information from DNA to the ribosomes in the cytoplasm where the process

of translation uses the genetic code on the RNA to form proteins from amino acids (one strand).

messenger RNA (mRNA): carries the genetic information from DNA to ribosomes in the cytoplasm. Translation converts the information in the mRNA into a sequence of amino acids that make proteins. Transfer RNA

(tRNA) brings the amino acids to the mRNA at the ribosomes so protein synthesis can take place.

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RNA codons must join with the correct anticodon of the tRNA. A codon is a group of three nitrogenous bases on an

mRNA molecule that carries the code for a specific amino acid. An anticodon is a set of three nitrogenous bases on

a tRNA molecule that matches a codon on an mRNA molecule.

Using Mendel’s laws, explain the role of meiosis in reproductive variability

dominant trait that appeared in the first generation

recessive the trait that seemed to disappear. Today, scientists call these factors genes. Alleles alternate forms of Genes are located on the chromosomes

1 from female & 1 from male

genotype is a list of the alleles for a particular trait in an

organism.

phenotype is the physical appearance of an organism, or how the

alleles influence the function of that particular gene in the organism.

homozygous If the two alleles in a

pair are identical heterozygous If the two alleles are

different

monohybrid crosses involve 1 trait,

dihybrid crosses involve two traits.

Punnett square will give the

possible results of genetic crosses.

Set up a dihybrid cross

with: 1-3 1-4 2-3 2-4

Dihybrid Cross

Structure of DNA

Differences in DNA & RNA

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Somatic cell Cell that makes up all of the body tissues and organs. Does not include gametes (or sex cells: egg & sperm). Any cell that is NOT a sex cell in an organism.

Gamete Sex cell; an egg or a sperm cell

Homologous chromosome Chromosomes that have the same length, appearance, and copies of genes, although the alleles may differ. A homologous pair of chromosomes consists of one chromosome from each parent.

Autosome Chromosome that contains genes for characteristics not directly related to the sex of the organism. For example, in humans, there are 22 pairs of autosomes. The X and Y chromosomes are not autosomal.

Sex chromosome Chromosome that directly controls the development of sexual characteristics.

Sexual reproduction Process by which two gametes fuse and offspring that are a genetic mixture of both parents are produced.

Fertilization Fusion of an egg and sperm cell.

Diploid Cell that has two copies of each chromosome, one from an egg and one from a sperm.

Haploid Cell that has only one copy of each chromosome.

Haploid vs. Diploid There are two types of cells in the body - haploid cells and diploid cells. The difference between haploid and diploid cells is related to the number of chromosomes that the cell contains.

Diploid cells contain two complete sets (2n) of chromosomes. Diploid cells reproduce by mitosis making daughter cells that are exact replicas.

Haploid cells have half the number of chromosomes (n) as diploid - i.e. a haploid cell contains only one complete set of chromosomes. Haploid cells are a result of the process of meiosis, a type of cell division in which diploid cells divide to give rise to haploid germ (sex cells, egg and sperm) cells. A haploid cell (egg or sperm) will merge with another haploid cell at fertilization.

Meiosis Form of nuclear division that divides a diploid cell into haploid cells; important in forming gametes for sexual reproduction. A type of cell division that forms sex cells (egg and sperm).

Gametogenesis Process by which gametes are produced through the combination of meiosis and other maturational changes.

Sperm Male gamete (male sex cell)

Egg Female gamete (female sex cell)

Polar body Haploid cell produced during meiosis in the female of many species; these cells have little more than DNA and eventually disintegrate.

Trait Characteristic that is inherited.

Genetics Study of the heredity patterns and variation of organisms.

Purebred Type of organism whose ancestors are genetically uniform. Purebred - Organism with identical alleles/genes for a trait (homozygous).

Cross Mating of two organisms

Law of independent assortment

Mendel’s second law, stating that allele pairs separate from one another during gamete formation.

Law of segregation Mendel’s first law stating that:

3. Organisms inherit 2 copies of genes, one from each parent 4. Organisms donate only one copy of each gene in their gametes because the genes

separate during gamete formation.

What is the difference in Law of independent assortment and Law of segregation?

3. Mendel's law of Segregation states that two alleles for a particular gene segregate (or separate) from each other during gamete formation and end up in different gametes.

4. Mendel's law of Independent Assortment states that each pair of alleles segregates independently of other pairs of alleles during gamete formation. In other words, traits are transmitted to offspring independently of one another.

For Example:

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Let's pretend I only have genes for hair color and eye color, one dominant and one recessive for each. We'll say that I have one blonde hair gene and one brown hair gene, and one blue eyes gene and one brown eyes gene.

The law of segregation says that when I make gametes (sperm or eggs), the alleles for my eye color genes will separate. An egg may get the blue eye gene or the brown eye gene, but not both. Same for hair. Exactly one allele from each pair of alleles is found in each gamete (assuming there are no mistakes).

The law of independent assortment says that whether an egg gets the blue eyes gene or brown eyes gene does not depend on whether it gets the brown hair gene or blonde hair gene. Therefore, brown hair + blue eyes, brown hair + brown eyes, blonde hair + blue eyes, and blonde hair + brown eyes are all possible. They are randomly assorted, not linked together in patterns.

Gene Specific region of DNA that codes for a particular protein

Allele Any of the alternative forms of a gene that occur at a specific place on a chromosome

Homozygous Characteristic of having two of the same alleles at the same locus of sister chromatids. If you're homozygous, you've got a pair of matching alleles, which are the two genes that control a particular trait.

Heterozygous Characteristics of having two different alleles that appear at the same locus of sister chromatids. The genetics term heterozygous refers to a pair of genes where one is dominant and one is recessive — they're different

Genome All of an organism’s genetic material.

Genotype Collection of all of an organism’s genetic information that codes for traits.

Phenotype Collection of all of an organism’s physical characteristics.

Dominant Allele that is expressed when two different alleles are present in an organism’s genotype.

Recessive Allele that is not expressed unless two copies are present in an organism’s genotype.

Punnett square Model for predicting all possible genotypes resulting from a cross, or mating

Monohybrid cross Cross, or mating, between organisms that involves only one pair of contrasting traits.

Testcross Cross between an organism with an unknown genotype and an organism with a recessive phenotype.

Dihybrid cross Cross, or mating, between organisms involving two pairs of contrasting traits.

Probability Likelihood that a particular event will happen.

Crossing over Exchange of chromosome segments between homologous chromosomes during meiosis I.

Genetic linkage Tendency for genes located close together on the same chromosome to be inherited together.

Synapsis The fusion of chromosome pairs at the start of meiosis.

Cell cycle Includes: Gap 1 Synthesis Gap 2 Mitosis

Pattern of growth, DNA replication, and cell division that occurs in a eukaryotic cell. Includes

the stages listed below:

Gap 1 (G1)-first stage of cell cycle. During G1, a cell carries out its normal functions. It

increases in size, and organelles increase in number. A cell spends most of its time in the

G1 state, although the length of this stage varies by cell type.

Synthesis (S)- the second stage of the cell cycle. During the S stage, the cell makes a copy

of its nuclear DNA. During interphase (which includes G1, S, and G2), the DNA strands are

uncoiled (uncondensed) in the nucleus. This uncondensed genetic material is called

chromatin; thus an uncondensed chromosome can be called chromatin. By the end of the

S stage, the cell nucleus contains two complete sets of DNA.

Gap 2 (G2)- Gap 2 is the third stage of the cell cycle. During G2, cells continue to carry out

their normal functions, and additional growth occurs. Like G1, this stage includes a critical

checkpoint. Everything must be in order—adequate cell size, undamaged DNA—before

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the cell goes through mitosis and division.

Mitosis (M)- Mitosis, the fourth stage of the cell cycle, includes two processes: mitosis and

cytokinesis. Mitosis is the division of the cell nucleus and its contents. During mitosis, the

nuclear membrane dissolves, the duplicated DNA condenses around proteins called

histones and separates, and two new nuclei (plural for nucleus) form. Lastly, cytokinesis is

the process that divides the cell cytoplasm. The result is two daughter cells that are

genetically identical to the original cell. Mitosis is a form of asexual reproduction.

Mitosis Process by which a cell divides its nucleus and contents.

Cytokinesis Process by which the cell cytoplasm divides

Chromosome Long, continuous thread of DNA that consists of numerous genes and regulatory information

Histone Protein that organizes chromosomes and around which DNA wraps.

Chromatin Loose combination of DNA and proteins that is present during interphase

Chromatid One half of a duplicated chromosome

Centromere Region of condensed chromosome that looks pinched; where spindle fibers attach during meiosis and mitosis

Telomere Repeating nucleotide at the ends of DNA molecules that do not form genes and help prevent the loss of genes.

Prophase First phase of mitosis when chromatin condenses, the nuclear envelope breaks down, the nucleolus disappears, and the centrosomes and centrioles migrate to opposite sides of the cell

Metaphase Second phase of mitosis when spindle fibers align the chromosome along the cell equator.

Anaphase Third phase of mitosis during which chromatids separate and are pulled to opposite sides of the cell

Telophase Last phase of mitosis when a complete set of identical chromosomes is positioned at each pole of the cell, the nuclear membranes start to form, the chromosomes begin to uncoil, and the spindle fibers disassemble.

Asexual reproduction Process by which offspring are produced from a single parent; does not involve the joining of gametes.

Binary fission Asexual reproduction in which a cell divides into two equal parts.

Somatic cell Cell that makes up all of the body tissues and organs. Does not include gametes (or sex cells: egg & sperm). Any cell that is NOT a sex cell in an organism.

Crossing Over Further genetic variation comes from crossing over, which occurs during prophase I of meiosis I. The replicated homologous pair of chromosomes comes together in the process called synapsis, and sections of the chromosomes are exchanged.

Mitosis- asexual Mitosis- asexual reproduction by simple cell division and DNA is divided equally between two daughter cells.

In mitosis in eukaryotes, the DNA is sorted into 2 new nuclei. A separate process divides the cytoplasm in two keeping the

number of chromosomes constant from one cell generation to the next.

In mitosis in multi- cellular organisms, cell division allows them to grow. It develops from a single cell into a multi-

cellular organism, and make other cells to repair and replace worn-out

cells.

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Mendel predicted how traits are carried from one generation to the next using pea plants. When he manually fertilized

parent plants tall T plants with short plants, the first generation of offspring (F1) were all tall T. When he let the F1 plants self-pollinate, 3/4 of their offspring (F2) were tall and 1/4 of the F2 plants were short (recessive)

Mendel’s work can be summarized in three laws: Law of Dominance dominant allele will prevent the recessive allele from being expressed. The recessive allele will

appear when it is paired with another recessive allele in the offspring.

Law of Segregation (separation) gene pairs separate when gametes are formed, so each gamete (sex cell) has only

one allele of each pair. Law of Independent Assortment states that different pairs of genes separate independently of each other when

gametes are formed.

Meiosis (2 phases) – Sexual how gametes (sex cells- sperm/eggs) are produced- Reduces the number of chromosomes in the gamete to 1/2 the number of parent’s chromosomes. When fertilization occurs and restores original chromosome number, the union of two gametes form a zygote. This process consists of two cell divisions but only one chromosome replication.

• Meoisis 1 produces two cells containing half the number of double stranded chromosomes (diploid (2n) cells)

chromosomes (haploid (1n) cells

•Meoisis 2 produces four cells, containing half the number of single-

stranded

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Describe the relationships between changes in DNA and appearance of new traits Sources of Variation during Meiosis The way that the chromosome pairs line up at the equator influence how they are distributed to the gametes. pea plant =7 pairs of chromosomes- each lines up during meiosis producing 128 (27) different trait combinations. Humans= 23 pairs of chromosomes/ 8 million different trait /fertilization makes 70 trillion combinations!

Crossing Over two chromosomes physically overlap and exchange chromosome material changes the DNA sequence

within each chromosome.

genetic recombination reassortment of chromosomes and the genetic information they carry

DNA gene mutations Changes in the nucleotide sequence of a DNA molecule and cause a change in the protein.

Mutagens harm DNA such as tobacco - ultraviolet light, ionizing radiation, free radicals..

Spontaneous mutations -result of replication errors. (alterations that can occur during meiosis)

Base pair substitutions one nucleotide base is replaced by another. sickle-cell anemia

base insertion mutation an extra nucleotide base causing creation of abnormal protein.

base deletion mutation is the removal of a nucleotide base causing creation of abnormal protein. Molecular clock Theoretical clock that uses the rate of mutation to measure evolutionary time ---the rate at

which nucleotide (amino acid) substitutions occur in a given DNA (protein) sequence.

Mutation Change in the DNA sequence

Mutagen Agent that can induce or increase the frequency of mutation in organisms

Missense mutation This type of mutation is a change in one DNA base pair that results in the substitution of one amino acid for another in the protein made by a gene.

Nonsense mutation A nonsense mutation is also a change in one DNA base pair. Instead of substituting one amino acid for another, however, the altered DNA sequence prematurely signals the cell to stop building a protein. STOP codon is created, but is not supposed to be there. This type of mutation results in a shortened protein that may function improperly or not at all.

Chromosomal Mutations A chromosome mutation is an unpredictable change that occurs in a chromosome. These changes are most often brought on by problems that occur during meiosis (cell division process of gametes) or by mutagens (chemicals, radiation, etc.). Chromosome mutations can result in changes in the number of chromosomes in a cell or changes in the structure of a chromosome. Unlike a gene mutation which alters a single gene or larger segment of DNA on a chromosome, chromosome mutations change and impact the entire chromosome.

Gene Mutations A gene mutation is a permanent alteration in the DNA sequence that makes up a gene, such that the sequence differs from what is found in most people.

Chromosomal Mutations

(An entire chromosome is affected in chromosomal mutations)

Deletion (Gene or Chromosomal depending how severe a deletion)

A piece of chromosome is lost, together with any genes which may be on it. A deletion changes the number of DNA bases by removing a piece of DNA. Small deletions may remove one or a few base pairs within a gene, while larger deletions can remove an entire gene or several neighboring genes. The deleted DNA may alter the function of the resulting protein(s).

Duplication Part of a chromosome is repeated. A duplication consists of a piece of DNA that is abnormally copied one or more times. This type of mutation may alter the function of the resulting protein.

Inversion Inversion: a kind of mutation in which the order of the genes in a section of a chromosome is reversed

Translocation Translocation: part of a chromosome gets moved onto another chromosome.

Insertion Insertion: a smaller chromosome is inserted into a longer chromosome.

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Nondisjunction A problem in meiosis in which there is a failure of paired homologous chromosomes to separate; results in an abnormal number of chromosomes in the daughter cells. An example of this is Down’s Syndrome in which there are 3 chromosomes (two from mother & one from father) on chromosome 21 instead of only two (one chromosome from each parent). The egg that was formed during meiosis by the mother failed to separate out chromosome 21 (nondisjunction) which resulted in two chromosomes being passed down to the offspring instead of only one from the mother.

Gene Mutations

(Only a gene within a chromosome is affected in gene mutations)

Duplication Duplication: where whole genes are duplicated.

Frameshift mutation Mutation that involves the insertion or deletion of a nucleotide in the DNA sequence. This type of mutation occurs when the addition or loss of DNA bases changes a gene's reading frame. A reading frame consists of groups of 3 bases that each code for one amino acid. A frameshift mutation shifts the grouping of these bases and changes the code for amino acids. The resulting protein is usually nonfunctional. Insertions, deletions, and duplications can all be frameshift mutations.

Insertion Insertion, where one or more extra base is put in. An insertion changes the number of DNA bases in a gene by adding a piece of DNA. As a result, the protein made by the gene may not function properly.

Deletion Removal of a base pair within a gene; where one or more bases are left out.

Point Mutation Mutation that involves a substitution of only one nucleotide (occurs at a single “point”)

Substitution Where one or more bases are substituted for another base in the sequence

BIOTECHNOLOGY Restriction Enzyme Enzyme that cuts DNA molecules at specific nucleotide sequences.

Restriction Map Diagram that shows the lengths of fragments between restriction sites in the strand of DNA

Gel Electrophoresis Method of separating various lengths of DNA strands by applying an electrical current to a gel

Polymerase Chain Reaction (PCR)

Method for increasing the quantity of DNA by separating it into two strands and adding primers and enzymes.

Primer Segment of DNA that stars replication by DNA polymerase.

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DNA Fingerprint Unique sequence of DNA base pairs that can be used to identify a person at the molecular level.

Clone Genetically identical copy of a single gene or an entire organism.

Genetic Engineering Process of changing an organism’s DNA to give the organism new traits.

Recombinant DNA Genetically engineered DNA that contains genes from more than one organism or species

Plasmid Circular piece of DNA found in bacteria that can replicate separately from the DNA of the main chromosome.

Transgenic Organism whose genome has been altered to contain one or more genes from another organism or species.

Gene Knockout Genetic manipulation in which one or more of an organism’s genes are prevented from being expressed

Genomics Study and comparison of genomes within a single species or among different species.

Gene Sequencing Process of determining the order of DNA nucleotides in genes and genomes.

Human Genome Project Project whose goal is to map, sequence, and identify all of the genes in the human genome.

Bioinformatics Use of computer databases to organize and analyze biological data.

DNA microarray Research tool used to study gene expression

Proteomics Study and comparison of all the proteins made by an organism’s genome.

Genetic Screening Process of testing DNA to determine the chance that a person has, or might pass on, a genetic disorder

Gene Therapy Procedure to treat a disease in which a defective or missing gene is replaced or a new gene is put into a patient’s genome.

Forensics Forensic science is a kind of science that uses many different scientific methods to look at evidence, solve crimes and resolve other issues dealing with the law. PCR analysis is a technique that allows technicians to create millions of precise DNA replications from a single sample of DNA. PCR can let forensic scientists perform DNA analysis on samples that are as tiny as only a couple of skin cells. A part of forensics uses DNA fingerprinting to identify criminals based upon DNA matches found at crime scenes.

Genetically Modified Organisms

Genetically modified organisms (GMOs) are living organisms whose genetic material has been artificially manipulated in a laboratory through genetic engineering. A GMO (genetically modified organism) is the result of a laboratory process where genes from the DNA of one species are extracted and artificially forced into the genes of an unrelated plant or animal. The foreign genes may come from bacteria, viruses, insects, animals or even humans. Because this involves the transfer of genes, GMOs are also known as “transgenic” organisms.

Advantages of Sexual and Asexual Reproduction Asexual reproduction

does not require another partner

quicker than sexual reproduction - many identical offspring in a short period of time.

resulting organism is identical genetically to the parent organism.

advantageous in stable environment where parent genotype is well-suited (colonizers of new environments)

Sexual reproduction Genetic variability that results from the process of meiosis (greater diversity).

Increases chance offspring will have more advantageous traits than parents.

Advantageous in a rapidly changing environment - diversity of the population increases chance some will both survive and reproduce.

Disadvantage more time than asexual (mating, meiosis, offspring growing)

Advances in DNA Technology and Genetic Engineering Medicine: reinserting a corrected gene replace damaged gene

Forensics: labs id people from crime scenes through DNA fingerprinting. (blood, hair samples)

Agriculture: biologists produce plants with desirable traits.(disease and herbicide resistance, more nutritious.

Genetic Engineering: researchers cut, splice together, and insert modified DNA molecules from different species into

bacteria or animal cells that rapidly replicate and divide. EX (mass produced insulin) Genetically modified cotton resist worms

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which results in increased cotton and is ecologically safer than pesticides. Scientists developed genetically altered bacteria to eat up oil spills, manufacture alcohol and process minerals but risk introduced into the environment.

EVOLUTION

Evolution is the process of biological change by which descendants come to differ from their ancestors.

Catastrophism is the idea that past natural disasters (like floods and volcanic eruptions) shaped landforms, and caused

species to become extinct in the process.

Gradualism is the idea that landforms were shaped by very slow changes over a long period of time, and not by natural

disasters.

Uniformitarianism is the idea that the same processes that shaped landforms in the past also shape landforms today.

Variation means the differences in the physical traits among individuals in a group of organisms.

An adaptation is a feature that allows an organism to better survive in its environment.

In a process called artificial selection, humans select individuals with the traits they desire, and then breed them to

produce more individuals with those traits.

Heritability is the ability of a trait to be passed down from one generation to the next.

Natural selection is a process in which individuals that have inherited beneficial adaptations produce more offspring

than do other individuals.

There are four main principles to the theory of natural selection: Variation, overproduction, adaptation, and descent with modification.

Variation- individuals of a species differ due to genetic variation. Heritable differences are the basis for natural

selection.

Overproduction- organisms have more offspring than can survive. This results in competition among offspring

for resources.

Adaptation- some individuals have certain variations that allow them to survive better than other individuals in

their environment. These individuals are “naturally selected” to live longer and produce more offspring that also have those adaptations.

Descent with modification- over time, natural selection will result in species with adaptations that are

beneficial for survival and reproduction in a particular environment.

Biogeography-the study of the distribution of organisms around the world.

Embryology- the study of embryos and their development.

Homologous structure- features that are similar in structure, but appear in different organisms and may have

different function. For example, the front limbs of humans, bats, and moles.

Analogous structures- structures that perform a similar function, but are not similar in origin. For example, birds and

butterflies have wings, but their winds do not share a common origin. Bird wings have bones and butterfly wings do not.

Vestigial structure are small leftover organs or structures that had a function in an early ancestor.

Paleontology is the study of fossils or extinct organisms.

Genetic drift- changes in allele frequencies that are due to chance

Bottleneck effect- genetic drift that occurs after a population has been greatly reduced in size. A natural disaster, for

example, can leave only a few survivors of a population.

Founder effect: is a genetic drift that occurs after a small number of individuals begin to live in a new area.

Divergent evolution- is when closely related species evolve in different directions, and become increasingly different.

Convergent evolution- is when unrelated species evolve similar characteristics.

Directional selection- selection that favors a phenotype at one end, or extreme, of a range.

Stabilizing selection- selection that favors the middle, or intermediate, phenotype.

Disruptive selection- selection that favors both extreme phenotypes.

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Reproductive isolation- is when members of different populations can no longer mate successfully to produce viable

offspring. (Viable means capable of living, developing, and reproducing)

Sexual selection- occurs when a trait increases mating success, and gets passed on to the next generation.

Speciation- the process of one species becoming two or more separate species.

Behavioral isolation- isolation caused by differences in courtship and mating behaviors.

Intrasexual selection- involves competition among males, such as the head butting of bighorn sheep.

Intersexual selection- occurs when males display certain traits that attract the female, such as peacocks fanning out

their tails.

Geographic isolation- members of different populations cannot mate due to a physical barrier like a mountain or river.

Temporal isolation- members of different populations cannot mate when timing prevents reproduction between

populations. For example, two pine tree species in California are separated in this way. One species sheds its pollen in February, while the other sheds its pollen in April.

Coevolution- the process in which two or more species evolve in response to changes in each other.

Extinction- is the permanent loss of species from Earth.

Background extinctions- extinctions that occur continuously, but at a low rate. Usually only one or a few species are

affected in a particular area.

Mass extinctions- extinctions that destroy many species, often all across Earth, are called mass extinctions. Mass

extinctions are thought to occur suddenly in geologic time, because of a dramatic event like an ice age or an asteroid impact.

Punctuated equilibrium- is a theory that describes a pattern of long periods of little evolutionary change (equilibrium)

are interrupted by shorter periods of intense evolutionary events, such as speciation (punctuated).

Adaptive radiation- the evolutionary process of splitting one species into a number of different species, each adapted

to a different environment.

Gene pool- Collection of alleles found in all of the individuals of a population.

Allele frequency- Proportion of one allele, compared with all the alleles for that trait, in the gene pool.

Phenotype- Collection of all of an organism’s physical characteristics.

Genetic Variation- Genetic variation is a term used to describe the variation in the DNA sequence in each of our

genomes. Genetic variation results in different forms, or alleles of genes. Genetic variation is what makes us all unique, whether in terms of hair color, skin color or even the shape of our faces.

Recombination- Recombination is a process by which pieces of DNA are broken and recombined to produce new

combinations of alleles, especially by crossing over in chromosomes. This recombination process creates genetic diversity at the level of genes that reflects differences in the DNA sequences of different organisms.

Hybridization- The act or process of mating organisms of different varieties or species to create a hybrid

Microevolution- Observable change in the allele frequencies of a population over a few generations

Gene flow- Physical movement of alleles from one population to another

Normal Distribution- Distribution in a population in which allele frequency is highest near the mean range value and

decreases progressively toward each extreme end.

Isotopes- are atoms of an element that have the same number of protons but a different number of neutrons. Some

isotopes are unstable and decay, or break down, over time into a different form or element. The rate at which an isotope decays can be measured in terms of half-lives.

Half-life- is the amount of time it takes for half of the isotope in a sample to break down into its different form.

Trace the history of the theory 1809 Jean Baptiste de Lamarck presented theory that all life forms evolved and that the driving force of evolution was the inheritance of acquired characteristics. changing due to the demands of environment. (giraffe neck)

Influenced Darwin /information he gathered Charles Lyell’s Principles of Geology(1830). proposed that plant and animal species had arisen, developed

variations, and then became extinct over time while Earth’s physical landscape changed over a long periods

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Thomas Malthus’ An Essay on the Principle of Population (1789). Malthus proposed that populations

outgrew their food supplies, causing competition between organisms and a struggle for survival

40,000-mile trip on the Beagle. Fossils in Patagonia- plants & animals varied due to geographical location.

Galapagos Islands, Darwin found many species specific to the various islands.

Darwin’s theory of evolution concepts (reproductive success) 1 Variations within a species were dependent on the environment

Adaptations genetically coded traits that occur in organisms and enable them to be more successful in their

environment, helping organisms survive and reproduce passed on advantageous traits to future generations.

Natural selection changes in a population that occur when organisms with favorable variations for that particular

environment survive, reproduce, and pass these variations on to the next generation.

2 geographically separated from one another resulting in reproductive isolation. no interbreeding between organisms of the same species that are located on different islands (finches)

Darwin knew nothing about genes or principles of heredity. Scientists put together the concepts of natural selection

with genetics after rediscovering Mendel’s work decades after it was published in 1866 allowing scientists to account for phenotypic variations in populations.

population genetics. researchers use mathematical descriptions of genetic phenomena to trace evolutionary trends

within populations.

Russel Wallace created another evolution theory based on the idea of competition for resources as the main force in natural selection using Darwin’s data that supported his idea, becoming the dominant evolutionary theory.

Modes of Evolutions Adaptive radiation species diversity occurs in a relatively short time. It occurs when a population colonizes a new

area (many species finches in Galapagos evolving from 1 species) Convergent evolution. unrelated species may independently evolve superficial similarities because of their

adaptations to similar environments. Data collected show that segments of DNA, and even entire sequences of the amino acids in some proteins, seem to be identical in many organisms.

Myosin is a protein found in muscle cells of humans and multi-cellular organisms cause movement. It is also found in

yeast cells to allow organelles to move within the cell.

Biodiversity variety of organisms, their genetic information, and the communities they live in

Ecosystem diversity - variety of habitats, living communities, & ecological processes in the living world.

Species diversity includes the vast number of different organisms on Earth. Genetic diversity all the different forms of genetic information carried by all living organisms on Earth. Giving rise to

inheritable variation, scientists believe provides the raw material for evolution.

Molecular clocks are proteins that have changed very slowly & are shared by many species.

Speciation is the evolution of a new species that occurs due to changes in gene flow in populations of the ancestral species.

geographic isolation occurs when physical barriers cause populations to divide and prevent mating of

individuals ( Volcanoes, sea-level changes, and earthquakes)

Gradualism is evolution that occurs over a long period of time when adaptive changes accumulate slowly and steadily over

time in a population. Darwin believed in gradualism.

Punctuated equilibrium speciation occurs quickly in rapid bursts, with long periods of stability.

Evaluating the scientific evidence that supports the theory of evolution (more info?) fossil record

biochemistry

embryologic development

homologous structures

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Explain how fossil and biochemical evidence support the theory incomplete picture of the evolution of plants,animals. Most fossils are remains of hard parts of organism.

2/3 of all organisms were soft-bodied, so no fossils

problem =few fossil remains of any “intermediate” or transition forms.

Fossilation depended on where/how an organism died

Fossils could have been destroyed by erosion or pressure from overlaying rocks.

Radioisotope Dating determine relative ages of fossils within a time period using Carbon 14. Must know

the half-life of the isotope being measured

how much of the isotope was originally present in the fossil or in the rock containing the fossil

how much of the isotope is left

Determining the Age of Fossils. relative dating groups of fossils in specific rock layers so geologists can determine the age of the rocks, and use to

determine the age of the fossils and interrelationships between organisms

phylogeny is a description of the lines of descent of plants and animals. (horse evolution) phylogenetic tree shows the interrelationship of several species allowing biologists to infer likely phylogenies by

comparing morphological features, DNA sequences, and chromosomal characteristics.

Five mass Extinctions (permanent loss of a species)

End of the Permian period, when 96% of marine invertebrates became extinct.

End of the Cretaceous period, when they believe 60–75% of marine species died.

Relate natural selection to changes in organisms increases the organism’s survival rate and increases chances this will be passed on to future acts on an organism’s phenotype (indirectly on its genotype) resulting in adaptations allowing survival

Fitness reproductive efficiency of genotypes in an environmetal population organism’s structure, physiology, biochemistry, & behavior adapt. strongest, biggest, most aggressive not always have highest fitness rating).

Variety (Variation) in populations’ phenotypes & biological capabilities enable survival in wider ranges of

environments. Environment plays an important role in determining which alleles ensure survival.

Types of changes in organisms (selections) Natural selection does not increase the organism’s structural or behavioral complexity and does not produce new

genotypes and phenotypes. It does eliminates the less fit who don’t adapt.

Stabilizing Selection (normalizing selection) may maintain the status quo for a population in its genotype or in its

phenotype in an environment. common in environments that have remained stable over long periods. Ex. Animals in deep ocean. Directional Selection involves changes from one phenotypic property to a new one.

When environmental conditions favor the survival of individuals carrying a genetic variant, the outcome is an increase in the frequency of that variant in the population. Example – pesticide resistance -mosquitoes in swamp mutate protein to be resistant so successive generations could succeed .

Disruptive Selection results in the disappearance of intermediate or average forms between extreme variants. Will split a

species into two or more groups by strongly selecting against the intermediate phenotypes.

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Recognize the role of evolution to biological resistance biological resistance (type of directional selection) results in fraction of offspring carrying allele that is resistant to

pathogen who respond to the favorable environmental conditions and increases that population variant.

Viruses are constantly evolving in response to changes in their environment.

Slow change give biologists time to create vaccines against them = smallpox or measles. Fast change mutates too rapidly for vaccine like the flu.

Another virus adaptation is ability to live in two or more different hosts. Ex. One virus may originally live in pigs and then move into humans

Viruses carry their genetic information on eight pieces of DNA. So if two strains of the virus infect the same cell, some of those genes will get mixed up, resulting in a new strain of the virus.

Other Items You Need to Know

Scientific Method: 1. State the problem; 2. Gather information; 3. Form a hypothesis; 4. Test the hypothesis;

5. Record and analyze data; 6. State the conclusion; 7. Repeat the work

A scientific theory is an explanation of an aspect of the natural world that can be repeatedly tested, in accordance with the scientific method, using a predefined protocol of observation and experiment.

In general, a scientific law is the description of an observed phenomenon. It doesn't explain why the phenomenon exists or what causes it. The explanation of a phenomenon is called a scientific theory. It is a misconception that theories turn into laws with enough research.

The word biology is derived from the greek words /bios/ meaning /life/ and /logos/ meaning /study/ and is defined as the science of life and living organisms; the study of living things.

Biologist: This scientist studies living organisms and living systems.

Botanist: This scientist studies plants.

Ecologist: This scientist studies the relationship of living things with their living and nonliving environment.

Zoologist: This scientist studies animals and animal life

Paleontologist: Scientist who performs scientific study of life in the geologic past, especially through the

study of animal and plant fossils.