TAMING THE

TAKS TEST

Objective Three

Biology– Bacteria vs Virus– Evolution– Symbiotic Relationships– Food Chains, Webs, Pyramids– Biomes and Plant Adaptations

Bacteria vs Viruses

BacteriaRemember Bacteria are

Prokaryotes

Prokaryotic cells have no nucleus or membrane bound organelles, only ribosomes, a cell wall and a loop of DNA.

VirusViruses are not classified

as cells. They have only a protein coat and a piece of DNA or RNA. They are unable to reproduce without a host cell.

Bacteria vs Viruses

BacteriaTreatable with Antibiotics!Bacterial diseases:

Streptococcus: (Strep throat, scarlet fever)

E. coli : Bacteria found naturally in the large

intestine that provides nutrients for humans

Rhizobium: Bacteria that live in soil that transform atmospheric nitrogen and turn it into

useful nutrients (nitrates) for plants Lactobacillus: Bacteria used to make yogurt

and other dairy products.

VirusNot Treatable with

Antibiotics!Viral diseases:

Acquired Immune Deficiency Syndrome: transmitted sexually and in blood products, the HIV virus attacks the Helper T cells of the immune system, causing infections that

lead to death. Influenza: The flu virus mutates quickly so a

new vaccine is offered every year. Smallpox: A deadly disease causing terrible scars that was wiped out by widespread

vaccination several decades ago. Warts: blister-like bumps caused by viruses in

the skin. The common cold: Spread by contact.

Harm Cause disease in plants and animals, spoil food.

Invade specific cells of plants and animals, reproduce inside and then kill them. Benefits Produce food (ex.

yogurt), fix nitrogen in the soil, produce vitamin D in the large intestine, decomposers

Used in research

Bacteria Viruses

Evolution = Charles Darwin

• Charles Darwin sailed 5 years on a ship called the SS Beagle.

• He went to the Galapagos islands.

• He wrote a book called

Origin of Species

Evolution = Charles Darwin

• Evolution is not the idea that we came from monkeys like many people believe

What is Evolution?

• The central idea of biological evolution is that all life on Earth shares a common ancestor, just as you and your cousins share a common grandmother. Evolution means that we're all distant cousins: humans and oak trees, hummingbirds and whales.

Evolution = Natural Selction

• Natural selection is the process by which individual organisms with favorable traits are more likely to survive and reproduce than those with unfavorable traits.

• Survival of the fittest!

Populations of animals adapt to their environment by Natural Selection.

1.All species have variations (caused by genetic makeup…Mutations can cause variation).

2. Variation is inherited.

3. More species are produced than will live.

4. Those species that survive to reproduce will pass their characteristics (genes) on to the next generation those that don’t become extinct.

5. Over time, characteristics and behavior that allow the species survive are “selected” for. Unfavorable traits won’t be passed on.

Fossils

• Fossils are the preserved remains or traces of animals, plants, and other organisms from the remote past.

What is Speciation?

• A species is often defined as a group of individuals that actually or potentially interbreed in nature. In this sense, a species is the biggest gene pool possible under natural conditions.

• For example, these happy face spiders look different, but since they can interbreed, they are considered the same species: Theridion grallator.

•

Example of Speciation

» At that point genetic changes resulted in two separate fruit fly lineages, where previously there had just been one lineage. But why and how did it happen?

» The scene: a population of wild fruit flies minding its own business on several bunches of rotting bananas, cheerfully laying their eggs in the mushy fruit...

• Disaster strikes: A hurricane washes the bananas and the immature fruit flies they contain out to sea. The banana bunch eventually washes up on an island off the coast of the mainland. The fruit flies mature and emerge from their slimy nursery onto the lonely island. The two portions of the population, mainland and island, are now too far apart for gene flow to unite them. At this point, speciation has not occurred — any fruit flies that got back to the mainland could mate and produce healthy offspring with the mainland flies.

• The populations diverge: Ecological conditions are slightly different on the island, and the island population evolves under different selective pressures and experiences different random events than the mainland population does. Morphology, food preferences, and courtship displays change over the course of many generations of natural selection.

• So we meet again: When another storm reintroduces the island flies to the mainland, they will not readily mate with the mainland flies since they've evolved different courtship behaviors. The few that do mate with the mainland flies, produce inviable eggs because of other genetic differences between the two populations. The lineage has split now that genes cannot flow between the populations.

Reasons for Speciation

• Geographic Isolations - Scientists think that geographic

isolation is a common way for the process of speciation to begin: rivers change course, mountains rise, continents drift, organisms migrate, and what was once a continuous population is divided into two or more smaller populations

• Reduction of Gene flow• Reproductive Isolation - Genetically-based changes to these

aspects of mating could complete the process of reproductive isolation and speciation. For example, bowerbirds construct elaborate bowers and decorate them with different colors in order to woo females. If two incipient species evolved differences in this mating ritual, it might permanently isolate them and complete the process of speciation.

Life is a Diversity

• Diversity is a measure of how many different types of organisms live in an area. For example, a rainforest is a very diverse habitat (many different species of insects, plants and animals). A desert is not as diverse (lots of the same kind of cactus and a few species of animals).

Phylogenetic Trees are diagrams that show the relatedness (Phylogeny) of organisms based on physical and chemical similarities.

100mya

Present

A

B

C D E F G

A is the common ancestor. B is extinct. E and F are the most closely related.

All animals and plants have adaptations that help them survive in their environment.

Support/food storage: Above ground (prop) roots, Stiff cell walls in stems and trunks (vascular tissue that also carries water and food), Starch storage in roots.

Prevention of water loss: Waxy cuticle, stomata on leaves, reduced leaf surface area (cactus), seed coats.

Reproduction: Seed dispersal by wind and animals, colors to attract pollinators, pollen, coevolution with insects.

Defense: Toxins, thorns, bark.

Examples of Plant Adaptations:

Examples of Animal Adaptations:Protection and prevention of dehydration: exoskeletons, armor, scales, skin, kidneys.

Defense/Predation: Claws, teeth, well developed eye lens, sense of smell, speed, camouflage, armor, mimicry.

Reproduction: Eggs, internal fertilization, placentas, care of young, nesting.

Behavior

• Behavior – response to a stimuli (anything outside the body)

• Plants and Animals will do anything to stay alive…Look at these behaviors!

• http://waynesword.palomar.edu/lmexe10b.htm

Extinction

• No more of an organism– Ex – Dinosaurs

Here are some endangered species…

Basic Terms

• Ecology the study of interactions among organisms and between organisms and their environment

• Biotic factors living or once living parts of the environment

 • Abiotic factors non-living parts of the

environments (light, wind, water)

• Sun: main source of energy for life

• Biotic or Abiotic?

Practice Question

The table lists four groups of factors found in a particular ecosystem. Which group consists of only abiotic factors?

F Group 1G Group 2H Group 3J Group 4

H

Levels of Organization

One type of ecological interaction is a symbiotic relationship

Symbiosis is a close relationship between two or more species

There are several types of symbiosis.

commensalism

mutualism

parasitism

Parasitism

The parasite gains nutrients, shelter or some

benefit at the expense of the host.

Can you identify the parasite and

host in the pictures?

Mutualism

Honeybee and flower. Honeybee gets nectar. Flower spreads pollen. Both benefit.

3-way mutualism. The caterpillars have nectar organs which the ants drink from, and the acaciaacacia tolerates the feeding caterpillars. The ants provide some protection

for both plantplant and caterpillar.

Commensalism

One organism benefits while the other is neither helped nor harmed.

Barnacles on whale fin. Barnacles get food as whale swims. Whale is not helped or harmed.

More commensalism

Cattle egrets feed off the insects that cows stir up while grazing. Cows get nothing, egrets get fed!

Assuming both cow and chicken benefit from this relationship, what form of

symbiosis would this be?

Mutualism

Practice Question

Clown fish are reef fish that seek protection from predators by sheltering themselves among the stinging tentacles of sea anemones. Clown fish are territorial and can scare off predators of sea anemones. This relationship is an example of-A. neutralism

B. mutualism

C. parasitism

D. commensalism B

Practice QuestionIn Central America there is a tree called bulhorn acacia

(Acacia cornigera) that provides both food and shelter to a certain species of ant (Pseudomyrmex ferruginea). The ants live within the tree without causing it harm. In fact, the ants protect the tree by vigorously attacking and stinging other animals that try to eat it.

This relationship is an example of-A. PredationB. ParasitismC. MutualismD Commensalism C

Practice Question

A tick feeding on the blood of a dog is an example of —

A commensalism

B parasitism

C neutralism

D mutualism

B

Practice Question

Which of these best represents a mutualistic relationship?A. Bull snake/mouse

B. White-tailed deer/grass

C. Hummingbird/blossom

D. Spade foot toad/cricket

C

Predator and Prey Interactions

Predator = hunter

Prey = hunted

CompetitionOrganisms try to use the same ecological

resource in the same time at the same place.

Example of resources: Sunlight, water,

nutrients, food,

root space, prey,

mates

Hyena and vultures fighting over leftovers from the lion’s meal.

Practice Question

Which of the following is most likely to cause increases in a predator population?A. Fewer prey

B. A reduction in competition

C. More parasites

D. A period of droughtB

Practice QuestionInsecticides help humans compete with

insects for a resource. Which resource is most likely to be preserved for humans through the use of insecticides?

F SunlightG WaterH FoodJ Air

H

Two competing species can thrive in the same community if they have —

F the same habitat G different niches H similar diets J different life spans

Practice Question

G

Practice Question

Which word best describes the fungus in the situation to the right?

A PredatorB ProducerC ParasiteD Decomposer

A

Other Important Words To Know Before We Move On!

• Producer (Autotroph) - use the sun’s energy to produce (make) their own food. Plants and other photoysnthetic organisms.

• Consumer (Heterotroph) – Organisms that cannot make their own food. The main groups consist of herbivores, carnivores and omnivores. Herbivores consume the primary producers, which are mainly plants, and chlorophyll containing bacteria. These are the .vegetarians. of the world. Carnivores eat flesh or meat, which usually means the other consumer species. Omnivores are not specialized and eat both plants and animals.

• Decomposer - organisms that feed off of dead and decaying matter

Do You Remember Pac-Man?

• Pac-Man ate the dots, food, and the blue ghosts…• PUT A PAC-MAN AT THE END OF THE ARROW AND

THAT IS WHAT HE EATS!• THE RABBIT EATS THE GRASS

Food Chain

• What to Remember about Food Chains?– Starts with a Producer

(plant or photosynthetic organism)

– Then comes the Consumers (Primary, Secondary, Tertiary)

• Primary is a herbivore

Food Web

Food Web or Food Chain?

Energy is passed from the PRODUCERS (algae) to four different levels of CONSUMERS. Remember the arrowsarrows show the direction of ENERGY flowdirection of ENERGY flow

Practice Question

Plants Aphids Spiders Sparrows

In this food chain, the spiders are-

A. Producers

B. Primary consumers

C. Competitors

D. Secondary consumers

D

Energy Pyramid

How much energy gets passed on from one level to the next?

C’mon…do the math

10%

Energy Pyramid

Only 10% of the energy from one trophic level gets passed on to the next.

That means 90% of the energy is lost!!!

How?Energy is lost in the form of kinetic energy (movement, maintaining homeostasis and metabolism) and heat.

Biomass PyramidSame idea as the energy pyramid, but measures the dry mass of organisms found at a given trophic level. Guess how much biomass is passed on to the next trophic level…….

10%

10% Rule

Each trophic level harvests only about 1/10 (or 10%) of the

energy from the level below, so it can only support about one tenth (or 10%) the amount of

living tissue.

Practice Question

At which trophic level in a biomass pyramid, like the one above, are producers found?

A. 1 B. 2C. 3 D. 1 and 2

Autotrophs

Heterotrophs

A

Practice Question

The diagram represents a pyramid of biomass. Which of the following best explains why a pyramid shape is useful in this representation?

A Most of the food consumed is recycled at every trophic level.B Energy from the producers is equally

distributed in all trophic levels.C Decomposers receive a small amount of

energy from the biomass.D Each trophic level supports a lesser

amount of biomass.

D

Biomagnification

Hey…this pyramid looks upside-down!

Just a little pollution can build up to big problems.

Biomagnification

• results in higher concentrations of a substance in organisms at higher levels in the food chain (at higher trophic levels).

• Most noted with harmful chemicals such as Mercury (Hg) and DDT (pesticide)

• Also called bioaccumulation or biological magnification

Practice Question

Which of these organisms would have accumulated the largest concentration of a long-term chemical pollutant in their bodies?

A. PhytoplanktonB. GullsC. Lake TroutD. Zooplankton

Phytoplankton Zooplankton Gulls

Lake Trout

Smelt

B

Practice Question

In a typical forest community, plants are producers, rabbits are primary consumers, and wolves are secondary consumers. Which diagram correctly represents these relationships?

H

Practice Question

The diagram to the right is intended to show relationships in an ecosystem. What do the arrows represent?

F The direction of population migration

G Differences in dietary habitsH Progressively smaller organismsJ The direction of energy flow

J

How Plants Adapt to Their Environment?

• Desert – Cactus, small needles, no large leaves, not a lot of water therefore they have thick cuticles to hold water in.

• Rainforest – large leaves, trees, flowers everywhere because there is a lot of water.

• Fresh or Salt Water – lilly pads have stomata on top because that is where the sun is.

• Cold Biomes (Tundra or Taiga) – a lot of snow, so when it melts (summer) that is when plants grow, Christmas trees

What is a Stomata?The TAKS Test Might Ask• Cuticle = thick to hold water• Guard Cell = opens and

closes stomata• Stomata = regulates water,

food, gas exchange• Xylem = transports water

through the leaf• Phloem = transports food

through the leafGuard Cell

Stomata