Objective 3 Taks Review

Bacteria and Viruses, Ecology, Evolution and Adaptations

TEK 4C and 4D: Bacteria and Viruses

Cell Wall

Cytoplasm

Ribosome

Crystalline structure

Characteristic Bacteria Viruses

ShapeCrystalline structure.

LivingYes NO-nonliving particle

Geneticmaterial

DNA not inside a nucleus

DNA or RNA but not both.

MetabolismYes NO metabolism- does not use

energy

Reproduction

Yes-asexual (binary fission)

Not on own- must reproduce inside a living host cell

After viral reproduction, the host cell is killed /destroyed as new virus particles break out.

Cause disease

Yes –but only some do like Streptococcus, Tuberculosis and Diphtheria

Yes –all are parasites

Characteristic Bacteria Viruses

Helpful

Some- aid in digestion like E. Coli

Aid body in maintaining health

Decomposers (recyclers)

NO

Can it betreated withantibiotics?

YES- #1 treatment for bacterial infections is antibiotics

NO-antibiotics do not work for viruses.

Some viruses are forever (HIV, warts, herpes).

Some viruses must run their course (cold, influenza) until the body learns how to fight it off.

There are vaccines for some viruses (polio, small pox, chickenpox, influenza)

Characteristic Bacteria Viruses

How does a vaccine work?

• A vaccine is a dead or weakened virus or bacteria that are injected into the person so that the immune system learns how to recognize and fight off future infections.

What disease is caused by HIV (Human Immunodeficiency Virus)?

• AIDS or Acquired Immune Deficiency Syndrome which weakens the immune system by destroying a particular white blood cell called the helper T cell knocking out the body’s ability to recognize new infections.

TEK 9D & 12E Food Chains, Food Webs, and Food Pyramids

Vocab Review• Abiotic factors: (nonliving)-air,

soil, water• Biotic factors: all living

organisms • Producer: produce own food• Consumer: must eat food

• Herbivore: eat only producers• Carnivore:eat only consumers• Primary Consumer:1st to eat in food

chain; eat producers• Secondary Consumer: 2nd to eat in

food chain; eat 1st consumers (herbivores)

• Biomass: Total amount of mass of all living organisms living in an ecosystem. (Ex. There is more biomass in the rainforest than the desert)

Food Chain: shows one feeding relationship in an ecosystem.

• It shows the direction of energy flow as organisms eat other organisms to obtain energy to live.

• Where do plants ultimately get their energy from? – solar energy from the sun

Food Web:

• Shows many feeding relationships within an ecosystem.

• It also shows the direction of energy flow as organisms eat other organisms to obtain energy.

• It can be used to show how changes in population numbers of one species, like the grasshopper, could affect many other populations in the environment.

Sample Problem:

• If a pesticide kills many of the grasshoppers in the area, then the frog population would decrease, which would cause the snakes to eat more mice.

• 1’s in diagram represent producers.

• 2’s represent primary consumers.

• 3’s represent secondary consumers.

1 11

22

2

3

3

3

1 1 1

3

222

3

3

Energy Pyramids:

• Show the available amount of energy at each feeding level.

• Producers are always found in greater numbers than consumers and are placed on the bottom of the pyramid.

• Which level contains the highest available amount of energy?– Producers (bottom)

• 10% rule: Only 10% of the available energy at each feeding level can be transferred up to the next level.

• What % of energy is lost as heat or kinetic energy by the organisms in that level? – 90%

100 %

10 %

1 %

Biological Magnification:

• Increasing the concentration of toxic chemicals (such as DDT and mercury) in each higher level of a food web. DDT is a pesticide that was used worldwide to kill disease-causing insects like mosquitoes.

• These chemicals can be found in high concentrations in which level? – top carnivores

Sample Problem:

• Which organism would have the highest concentration of pollution?– Gulls

Symbiosis describes the close relationships between 2 different populations in which at least one organism is helped.

*Types of symbiosis:*• Parasitism – one benefits & one is harmed (Ex.

heartworms and a dog) Parasites only take nutrition from the host organism, its intent is not to kill. (-Parasites are not predators.)

• Commensalism – one benefits and the other is not harmed. (Ex. barnacles attach themselves to whales – the whale is not harmed and the barnacle has a place to live and a means of transport)

• Mutualism – both organisms benefit (Ex. You and bacteria (E. coli) in your intestines)

• 1. ____________A human losing blood to a feeding mosquito

• 2. __________Birds nesting in trees

• 3. ____________An oakworm caterpillar feeds on the leaves of an oak tree

• 4. ____________An orchid being pollinated by a nectar collecting hummingbird

• 5. ____________A tapeworm absorbing nutrients from the intestine of a dog.

Parasitism

Parasitism

Parasitism

Commensalism

Mutualism

A

B

C

Mutualism

Commensalism

Parasitism

TEKS 7A, 7B & 13B Evolution and Adaptations

Natural Selection:

• Nature selects those individuals with favorable traits to live longer and reproduce more fit offspring. Those things that can limit/pressure a population include predator/prey relationships, limited habitat, food & water.

Decent with Modification/ Speciation:

• Idea that today’s species are descendants of ancestral species with slight changes (due to mutations) that help them survive in an ever-changing environment.

An adaptation is the physical or behavioral trait an individual has that helps them survive and reproduce in a particular environment.

Examples of adaptations:

This leaf exchanges gases with the atmosphere using openings in the leaf called stomata (“T” in picture above.) Because water is also lost in a process called transpiration through these leaf openings, some plant adaptations to prevent water loss include less stomata per leaf in drier more arid environments.

Other Plant adaptations:

• Mangroves and other fresh/saltwater plants must be able to tolerate high levels of salt. Mangroves pump out the extra salt onto their leaves.

• Water lilies have stomata only on the top surface of their leaves.-(the part exposed to the air.)

• Desert plants because they live in arid (drier) regions, have long and extensive root systems to access water deep underground. Desert plants also have water retaining stems that can photosynthesize.

• The pitcher plant and venus fly trap use insects to get nutrients that are not available in the poor soils that they live in.

• Tropical rainforest plants have broad leaves to capture sunlight. Being broad/large these leaves can hold a lot of water. Rainforest leaves have a thick waxy coating to prevent too much water from being lost or absorbed.

• Deciduous trees of the also have broad leaves that hold water. These leaves can be destroyed by freezing temperatures. To conserve energy these leaves fall off in fall, storing energy in the form of sap in the roots until spring.