Taks Food Chains, Webs, Taks Food Chains, Webs, Pyramids, and Environmental Pyramids, and Environmental

InteractionsInteractionsAnother “Whaddaya Need to

Know to Pass the Taks” presentation

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• This presentation contains sample Taks This presentation contains sample Taks questions from released Taks tests with questions from released Taks tests with explanations. This power-point explanations. This power-point presentation can be printed with both the presentation can be printed with both the question and answer to a given question question and answer to a given question on a single page.on a single page.

Whaddaya Need To Know?Whaddaya Need To Know?• Not J - A period of drought would decrease

producers, thus decrease 10 consumers, and so decrease 2o consumers.

• Not H - More parasites would decrease the predator population

• Not F – less prey means less food, thus less predators.

• The answer is G – less competition for resources increases the resources available for the predators.

Whaddaya Need To Know?Whaddaya Need To Know?• Primary consumers are herbivores (plant

eaters). Secondary consumers are carnivores (meat eaters). Omnivores are both primary and secondary consumers (meat and plant eaters).

• Primary consumers include the mice and the raccoons because they eat the grass shrubs.

• The raccoon is also a secondary consumer when it eats mice.

• The answer is H, raccoons.

Whaddaya Need To Know?Whaddaya Need To Know?• Producers (plants) are the 1st trophic level

• Primary Consumers (herbivores) are the second trophic level.

• Secondary consumers (carnivores) are the 3rd trophic level.

• Both Hawks and Wolves eat primary consumers (the mice and rabbits), so the answer is C.

43 Approximately how much of the energy available in the tissues of the producer is eventually incorporated into the tissues of a secondary consumer?

A Less than 1%B Between 20% and 30%C Approximately 50%D More than 50%

Whaddaya Need To Know?Whaddaya Need To Know?• The 10% rule – only 10% or less of the energy

moves from one level to the next in a food pyramid.

• The cow consumes 1000 kcal of energy, but only 100 kcal are incorporated into the cow.

• The human consumes 30 kcal of energy, but only 3 kcal are incorporated into the human.

• From 1000 to 3 is less than 1%, so the answer is A.

Whaddaya Need To Know?Whaddaya Need To Know?• Food chains show a single line from producer

to the top-end consumer.

• Plants are the producers.

• Aphids are the primary consumers.

• The spiders get their energy from aphids, so they are the secondary consumers.

• The answer is D.

Whaddaya Need To Know?Whaddaya Need To Know?• Plants are photo-autotrophs – they use sunlight

to make their food.

• Photosynthesis converts the light energy from the sun, carbon dioxide, and water into sugars. Oxygen is also produced.

• Ultimately, all energy in a food chain, web, or pyramid originates from the sun.

• The answer is G.

Whaddaya Need To Know?Whaddaya Need To Know?• Again, all energy in a food chain, web, or

pyramid originates from the sun.

• The answer is G, photosynthesis.

Whaddaya Need To Know?Whaddaya Need To Know?• Both the clownfish and the anemone benefit.

– The clownfish has shelter within the tentacles of the anemone, and the anemone is defended by the clownfish.

• The answer is B, mutualism.

Whaddaya Need To Know?Whaddaya Need To Know?• Biological magnification is the phenomenon that the

highest concentrations of toxins can be found in higher order consumers.

• For example, a farmer spreads poison to kill grasshoppers. Many of the poisoned grasshoppers are eaten by the free range chicken and pond fish on the farm. The farmer eats the chickens and fish regularly. The highest concentration of poisons would be found in the farmer.

• The answer is D, the Gulls, because they are the highest order consumer.

Whaddaya Need To Know?Whaddaya Need To Know?• The mosquitoes are preyed upon by the frogs

and the martins.

• Martins are insect eating birds. Building martin houses would increase the martin population, thus decreasing the mosquito population, but this was not a choice.

• The frogs also eat mosquitoes. Increasing shelter for frogs would increase the frog population and reduce the mosquito population.

• The answer is D.

Whaddaya Need To Know?Whaddaya Need To Know?• The oak tree is being harmed by the caterpillar.

As it eats the leaves of the oak tree, the caterpillar is diminishing the ability of the tree to perform photosynthesis.

• The caterpillar benefits by using the living tree as a continuing food source.

• One benefits; the other is harmed.

• The answer is J, parasitic.

Whaddaya Need To Know?Whaddaya Need To Know?• Traditionally, fire ants have been controlled with

the poison Diazinon. However, Diazinon was found in water systems, and was deadly to beneficial organisms.

• To control fire ants without the use of poisons would require either an organism that preys on fire ants, or a parasite that uses fire ants as a host.

• The answer is D, a parasite that affects the ant’s larva.

Whaddaya Need To Know?Whaddaya Need To Know?• Omnivores are both primary and secondary

consumers (meat and plant eaters).• The answer is H, because ants eat both plants

and animals.

Whaddaya Need To Know?Whaddaya Need To Know?• Food pyramids can show relationships between

trophic levels in regard to numbers of individuals, energy available, or biomass.

• The answer is H, the amount of energy available at each level.

Whaddaya Need To Know?Whaddaya Need To Know?• Again, both organisms benefit. The

hummingbird receives nectar from the flower, and the flower is aided in pollination.

• Thus, the relationship is mutualistic.• The answer is J.

Whaddaya Need To Know?Whaddaya Need To Know?• Poison oak and poison ivy cause irritation

rashes in many mammals. Those animals that learn to recognize this plant will avoid eating or harming the plant. The plant protected.

• The answer is F - defense mechanism.

Whaddaya Need To Know?Whaddaya Need To Know?• The lower levels of a food pyramid contain

more energy than the higher levels.• The base of the food pyramid is the producer –

the plants that provide energy for the food pyramid through photosynthesis.

• The answer is D.

Whaddaya Need To Know?Whaddaya Need To Know?• Not A – tape worms are parasites. The worm

benefits and the dog is harmed.• Not D – An armadillo rooting in the soil is a

consumer – Primary if it eats roots, secondary if it eats insects.

• Not C – Mosquitoes are parasites. One benefits, the other is harmed.

• The answer is B – the wasp collects nectar, and the orchid is pollinated.

Whaddaya Need To Know?Whaddaya Need To Know?• Bacteria act as decomposers. • The answer is C.

Whaddaya Need To Know?Whaddaya Need To Know?• In this case, the fungus is a predator.• The answer is A.

Whaddaya Need To Know?Whaddaya Need To Know?• The lichen growing on the rotting log is breaking

down the log. In this case, it is a decomposer.• The answer is H.

Whaddaya Need To Know?Whaddaya Need To Know?• Both benefit, so this is mutualism.• The answer Is J.

Whaddaya Need To Know?Whaddaya Need To Know?• The greatest amount of energy is found in the

base of the pyramid. The greatest transfer, therefore is from U to T (the plankton to the shrimp).

• The answer is D.

21 The diagram above 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.

Whaddaya Need To Know?Whaddaya Need To Know?• The producers support the primary consumers,

which in turn support the secondary consumers.

• The answer is D, each level supports a level less mass.

Whaddaya Need To Know?Whaddaya Need To Know?• The 10% rule states that only 10% of the

energy of each trophic level is passed on to the next level. That means 90% is lost to heat and use by life processes.

• The answer is A, because each level is greatly reduced in energy as compared to the level below it.

Whaddaya Need To Know?Whaddaya Need To Know?• The two groups of organisms in this symbiotic

relationship are the epiphytes and the trees.• The epiphytes benefit by receiving more

sunlight.• The trees receive no benefit or harm.• The answer is H, commensalism.

Whaddaya Need To Know?Whaddaya Need To Know?• The sea turtles eat the jellyfish. • The jellyfish eat the krill. • The krill eat the phytoplankton. • The phytoplankton are photoautotrophs. • So, phytoplankton krill jellyfish turtles

(producer) 10 20 30

The answer is C.

The collared peccary is often mistaken for a pig. It has a short pig-like snout and crushing molars. The peccary has a mass of 10–20 kg and a shoulder height of about 50 cm. The collared peccary is omnivorous, eating mostly roots, seeds, fruit, cacti, and occasionally insects and mice. Peccaries travel in herds of 6–30 animals. The natural enemies of the peccary are bobcats and coyotes.

3 Which of these is a food web based on the relationships described above?

Whaddaya Need To Know?Whaddaya Need To Know?• The plants, mice, and insects provide energy

for the collared peccary. In a food web, the arrows show the flow of energy, so the arrows for the plants, mice and insects point toward the peccary.

• The peccary is preyed upon by the bobcats and coyotes, so the arrows point from the peccary to the bobcats and coyotes.

• The answer is B.

Whaddaya Need To Know?Whaddaya Need To Know?• Energy lost from one trophic level to the next is

given off as heat.• The answer is A.

Whaddaya Need To Know?Whaddaya Need To Know?• In a mutualistic relationship, both organisms

benefit.• The bacteria receive food, and the fish are

aided in digestion by the bacteria.• The answer is G.

Whaddaya Need To Know?Whaddaya Need To Know?• The arrows show the flow of energy from one

trophic level to the next.• The answer is J.

Whaddaya Need To Know?Whaddaya Need To Know?• Insects cause millions of dollars worth of

damage to agriculture each year. • Pesticides reduce the number of insects

preserving most of the crop for human consumption.

• The answer is H.