Midterm Review

Cell Theory:

- all thing things are composed (made of) cells

- cells are the basic units of structure and function in living things

- all cells are produced from other cells

- Robert Hooke was the 1st person to see cells under a microscope, Anton van Leeuwenhoek was the first person to see a living cell

cell, tissue, organelle, organ, organism, organ system

cell – the basic units of structure and function in living thingsTissue – a group of similar cells that work together to perform a specific functionOrgan – made of different kinds of tissues that function togetherOrgan system – group of organs that work together to perform a major function

enzymes – speed up chemical reactions in living things Osmosis – the diffusion of water molecules across a selectively permeable membrane.Active transport – movement of materials across a cell membrane using cellular energy.Passive Transport – the movement of dissolved materials across a cell membrane without using energy.

Engulfing – the way food particles are taken in during endocytosis.

Photosynthesis – cell captures sunlight and uses it to make food

Light energy + carbon dioxide + water glucose + oxygen

Cellular Respiration

Glucose + Oxygen carbon dioxide + water + energy

• Binomial nomenclature – giving each organism a unique scientific name

For example) humans are homo sapiens

• Element – any substance that cannot be broken down into simpler substances.

– Example ) carbon, nitrogen, hydrogen, oxygen

• Compound – two or more elements combined–Example) water H20

• Atom – the smallest unit of an element

The Cell Cycle

Interphase

- The cell grows, makes a copy of its DNA, and prepares to divide into two cells

- Mitosis – the cell’s nucleus divides into two new nuclei and one set of DNA is distributed into each daughter cell.

Mitosis

MITOSIS – 4 stages:

- Prophase :

- Metaphase :

- Anaphase:

- Telophase:

- Cytokinesis: - the final state of the cell cycle

- the cytoplasm divides

- two new cells are formed

Branching Tree Diagram

- Shows the probable evolutionary relationship among organisms and the order in which specific characteristics may have evolved.

Taxonomic Key

- Consists of paired statements that describe the various physical characteristics of different organisms.

What do all living things have in common?

- Have cells

- Contain similar chemicals

- Use energy

- Respond to their surroundings

- grow and develop

- Reproduce

- Homeostasis – cells of organisms are able to maintain internal stability.

Cells

Prokaryotes

• Cells without a nucleus

• Bacteria and archaea

Eukaryotes

• Cells with a nucleus

• Protists

• Fungi

• Plants

• animals

Parts of a Cell

proteins endoplasmic reticulum vacuole nucleolus

mitochondria membrane

golgi bodies organelles

nucleus

Use the words on the previous slide to fill in the blanks below.

• The ___________________ controls the materials that enter and leave the cell.

• Ribosomes make ______________.

• The storage area of a cell is called the ______________.

• ___________________ are in the nucleus where ribosomes are made.

• __________________ receives proteins and distributes them to other parts of the cell.

Use the words on the previous slide to fill in the blanks below.

• In the _________________ substances are produced.

• The ___________________ powerhouse of the cell; it converts energy stored in food to energy the cell can use.

• The _________________ is the control center of the cell.

• _______________________ are tiny cell structures that carry out specific functions within the cell.

Animal Cell

nucleus mitochondria golgi bodies

lysosome cell membrane ribosomes cytoplasm endoplasmic reticulum

Name two things a plant cell has that an animal cell does not have:

cell wall

chloroplasts

Fermentation

Fermentation is an energy releasing process that DOES NOT require oxygen.

Alcoholic fermentation :

– occurs in yeast and other single –celled organisms.

- it produces alcohol, carbon dioxide, and a small amount of energy

ex) making bread, wine, beer

Evolution and Classification

Convergent Evolution – the process by which unrelated organisms evolve characteristics that are similar.

ex) birds and insects both use wings to help them fly

Shared Derived Characteristic

A trait, such as fur, that the common ancestor of a group had, and passed on to its descendants.

Scientific Name

Scientific Name

genus – a classification grouping that contains similar closely related organisms

species – a group of similar organisms that can mated with each other and produce offspring that can also mate and reproduce.

Chapter 4 Heredity

Heredity – the passing of physical characteristics from parents to offspring.

Ex) hair color, eye color

Purebred- an organism of many generations that have the same form for a trait

Gregor Mendel

• Reasoned that individual factors or sets of genetic information must control the inheritance of traits

• An organisms traits are controlled by the alleles it inherits from it’s parents

• Some alleles are dominant, other alleles are recessive

*** Mendel’s work is historically significant because it showed that offspring traits are determined by individual, separate alleles inherited from each parent ***

Phenotype – an organism’s physical appearance or visible traits.

Ex) smooth, round, long

Genotype – an organism’s genetic makeup, or alleles.

Ex) BB, Tt, ss

Homozygous – an organism has two identical alleles for a trait.

Ex) BB, bb

Heterozygous – an organism has two different alleles for a trait.

Ex) Bb

Punnett Square – a chart that shows all the possible ways alleles can combine in a genetic cross.

Incomplete dominance – occurs when one allele is partially dominant

Ex) red and white flowers cross to make pink flowers

Codominance – occurs when both alleles for a gene are expressed equally

Ex)a red fish and blue fish cross and offspring is a blue and red fish

Multiple Alleles – three or more possible alleles determine the trait.

Ex) fur in a rabbitPolygenic Inheritance – occurs when more than one gen affects a trait

Ex) human height or time it takes for a plant to flower.Acquired trait – skills you learn and physical changes that occur

Ex) calluses, haircuts

Meiosis – the process by which the number of chromosomes is reduced by half as sex cells form

Chromosome Theory of Inheritance – genes pass from parents to offspring on chromosomes.

Chapter 5

• The order of the nitrogen bases along a gene forms a genetic code that specifies what type of protein will be produced.

• Proteins are made of amino acids.• A group of 3 DNA base codes makes up one specific amino

acid.• The nitrogen bases that pair together are :• Adenine – Thymine• Cytosine – Guanine• Two new daughter cells result when a cell divides. DNA

replication is the process in which an identical copy of a DNA strand is formed for a new cell.

Mutations

• A mutation is any change in the DNA of a gene or chromosome.

• Mutations can cause a cell to produce an incorrect protein during protein synthesis. As a result, the organism’s trait may be different from what it normally would be.

• Ex) Cancer is a disease in which the cells grow and divide uncontrollably, damaging parts of the body around them.

Sex Chromosomes

• Humans have 23 sex chromosomes.

• The sex chromosomes carry genes that determine a person’s sex as being either male or female. They also carry other traits.

• Meiosis – produces sex cells with half the number of chromosomes

• Mitosis – produces all other body cells

Genetics

Selective Breeding – selecting organisms with desired traits to be parents of the next generation

Ex) farmers saving seeds from the healthiest plants to plant the following year

Genetic engineering – genes from one organisms are transferred into the DNA of another organism

Ex) medicine and improve food crops

Gene therapy – inserting copies of a gene directly into a person’s cells

Ex) treating hemophilia by replacing the defective X chromosomes

RNA

• During protein synthesis, the cell uses information from a gene on a chromosome to produce a specific protein.

• Two types of RNA take part in protein synthesis:

• MESSENGER RNA – copies the message from DNA in the nucleus and carries the message to the ribosome in the cytoplasm.

• TRANSFER RNA – carries amino acids to the ribosome and adds them to the growing protein.

Evolution

Darwin’s Theory of Evolution – species change over many generations and become better adapted to new conditions.

• Natural Selection – the process by which individuals are better adapted to their environment and more likely to survive and reproduce more than other members of the same species.

• Can be based on factors:• Overproduction• Variation• Competition• Selection• Environmental change• Genes and natural selection

Evidence of Evolution

Fossils, patterns of early development, similar body structures, and similarities in DNA and protein structures all provide evidence that organisms have changed over time.

Patterns of Evolution

Gradualism

Species gradually change over time –small changes over

time.

Punctuated equilibrium

Species evolve during short

periods of rapid change, and then

don’t change much.

How do new species form?

A new species can form when a group of individual remains isolated from the rest of its species long enough to evolve different traits that prevent reproduction.