AP Environmental Science : Food Webs and Pyramids

Study concepts, example questions & explanations for AP Environmental Science

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Example Questions

Example Question #61 : Ecosystem Development And Relationships

Which of the following would be a secondary consumer?

Possible Answers:

A black-tailed deer that browses on grasses and shrubs

People who are keen to eat bear, which eats small mammals that live off berries and seeds

A western diamondback rattlesnake that preys on field mice that eat seeds and berries

Earthworms, bacteria and fungi that decompose plant matter on the forest floor to replenish the soil

A maple tree that stores energy harnessed from the sun in the form of sugars through a process called photosynthesis

Correct answer:

A western diamondback rattlesnake that preys on field mice that eat seeds and berries

Explanation:

A secondary consumer is a step above the primary consumer (herbivore) on the food chain, consisting of omnivores and carnivores. A mouse that lives off plant matter and is thus a primary consumer. When a snake eats the mouse, it is the secondary consumer in the food web.

Example Question #1 : Understanding Food Webs And Food Chains

What is the ratio of energy generated by producers to the energy absorbed by the next trophic level up, that of primary consumers?

Possible Answers:

Correct answer:

Explanation:

With every advancement in the trophic level, energy converts on a ten-to-one scale. For example, ten kilograms of grain fed to a steer produces roughly one kilogram of beef. This is true for every step up the tropic food pyramid.

Example Question #61 : Ecosystems And Biology

Carnivores, omnivores, herbivores, detrius feeders and decomposers are all parts of the:

Possible Answers:

Food web

Energy pryamid

Krebs cycle

Carbon cycle

Food chain

Correct answer:

Food web

Explanation:

The food web is a complex feeding relationship within a community including many organisms at various trophic (feeding) levels, with many of the consumers occupying more than one level simultaneously. Herbivores (plant eaters), Carnivores (meat eaters), omnivores (Latin, "eating all), detritus feeders (debris eaters) and decomposers (bactetia and fungi) are all part of the food web. A food chain illustrates who feeds on whom in a community in a linear feeding relationship. A food chain identifies a representative of each trophic level that eats the representative of the level below it. During the carbon cycle, carbon is captured from the atmosphere during photosynthesis and passed up through the trophic levels. It is released during respiration from all trophic levels and by the burning of forests and fossil fuels. The Krebs cycle is a series of reactions occurring in the mitrochondria in which ATP is formed, which is the major energy carrier in cells. An energy pyramid is a graphical representation of the energy contained in succeeding trophic levels, with maximum energy at the base and steadily diminishing amounts at higher levels. 

Example Question #1 : Food Webs And Pyramids

In relation to an energy pyramid, which of the following trophic levels would have the most energy stored in it?

Possible Answers:

Primary consumer

Tertiary consumer

Decomposers

Producer

Secondary consumer

Correct answer:

Producer

Explanation:

An energy pyramid shows maximum energy at the base and steadily diminishing amounts at higher levels. The predominant organisms in an ecosystem are plants. Plants have the most energy available to them, because they trap it directly from sunlight. Far more people can be fed on grain than on meat. Primary consumers (herbivores) that feed on plants store less energy. Secondary consumers that feed on the primary consumers store even less energy and tertiary consumers (usually carnivores) store even less. Decomposers liberate nutrients for reuse that return to the atmosphere, soil, and water. 

Example Question #1 : Food Webs And Pyramids

Historically, tigers ranged widely throughout Asia and ranged from Turkey into eastern Russia. They are now critically endangered, with just over 3,000 individuals left in the wild. The biggest threats to tigers are poaching by humans and disappearing habitat. Adult tigers need to consume 50-75 large prey animals per year to survive. Although some small-protected areas for tigers exist, tigers require a large home range with plenty of prey. Unfortunately, habitat fragmentation has detrimentally effected tiger populations because it has limited the spread and growth of prey. As a result, protective government programs would need to protect both the tigers as well as their prey species and habitats.

Based on the information in the passage, which of the following choices best describes the tiger species?

Possible Answers:

Keystone species

Indicator species

Foundation species

Umbrella species

Correct answer:

Umbrella species

Explanation:

Umbrella species are very similar to a keystone species; however, an umbrella species refers to a species that indirectly protects many other species of its ecological community during conservation. Usually, umbrella species are migratory or require a large habitat.

Example Question #63 : Ecosystem Development And Relationships

Which of the following is not a primary consumer?

Possible Answers:

Squirrel

Beaver

Worm

Deer

Correct answer:

Worm

Explanation:

Deer, beavers, and squirrels are all primary consumers. This means that these organisms are herbivores—they only consume plants. Worms are detritivores, which eat decaying organic matter (e.g. dead animals or plants).

Example Question #64 : Ecosystem Development And Relationships

With each increasing trophic level the amount of useable energy decreases while toxin concentrations increase. Which of the following produces increased toxin concentrations at higher trophic levels?

Possible Answers:

Bioluminescence

Bioremediation

Bioescalation

Biomagnification

Correct answer:

Biomagnification

Explanation:

Biomagnification is also known as bioamplification. It occurs when the amount of environmental toxins increases as consumers move up trophic levels. For example, DDT was used to control pests. Many bird species suffered from biomaginfication and died due the amplification of the toxin levels in their systems that resulted from the consumption of multiple insects exposed to DDT.

Example Question #65 : Ecosystem Development And Relationships

Food webs are useful representations of how organisms within a community interact with one another. Which of the following types of food webs represents the feeding relationships between organisms?

Possible Answers:

Predation web

Energy flow web

Functional web

Connectedness web

Correct answer:

Connectedness web

Explanation:

Only three of the answer choices represent actual types of food webs: connectedness, energy flow, and functional. Connectedness webs are the type of food web used to represent feeding relationships. In short, they show relationships between predators and their prey.

Example Question #66 : Ecosystem Development And Relationships

Some toxic compounds are ingested and retained in an organism's tissue. Such pollutants pose special risks to humans and other species high on the food chain because of which process?

Possible Answers:

Biomagnification

Threshold Effect

Synergism

Compound Contamination

Carcinogenesis

Correct answer:

Biomagnification

Explanation:

Biomagnification is the process whereby the tissue concentrations of a contaminant increase as it passes up the food chain through multiple trophic levels. The contaminant is accumulated as it ascends the ecological food chain by transfer of residues from the diet into body tissues (sometimes referred to as 'bioaccumulation'). 

The ascension of toxic compounds through the food chain does not depend on slow to rapid change like a threshold effect, not does it involve cooperation between organisms like synergism. Compound contamination refers to contamination of the environment itself, and carcinogenesis refers to the initial formation of cancer, not the spread of contaminants.

Example Question #62 : Ecosystems And Biology

What is secondary productivity? 

Possible Answers:

The productivity of plants through photosynthesis

The accumulation of biomass from herbivores and carnivores

The accumulation of biomass from primary consumers

The total biomass in a given ecosystem

Correct answer:

The accumulation of biomass from herbivores and carnivores

Explanation:

Secondary productivity is the biomass accumulation of all levels of consumers. Herbivores and Carnivores are always grouped together in terms of productivity. The productivity of plants and their biomass due to photosynthesis is Primary productivity. The total biomass of an ecosystem is the sum of Primary and Secondary productivity. 

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