Question 1

In 1956, people in Minamata, Japan, began to exhibit severe neurological disorders and birth defects. This problem was eventually attributed to methylmercury, a water- insoluble and breakdown- resistant chemical formed from mercury dumped into the adjacent bay by a local factory. Which of the following types of seafood would have the highest levels of methylmercury, and therefore cause the severest effects?

Accepted Answer

Tuna, being at the top of the food chain, accumulate the highest levels of methylmercury due to biomagnification, as they consume smaller fish that have already accumulated mercury from krill and algae.

Question 2

Which nutrient cycle lacks an atmospheric reservoir?

Accepted Answer

The phosphorus cycle lacks an atmospheric reservoir because phosphorus does not typically exist as a gas and is primarily found in rocks, soil, and sediments.

Question 3

is (are) a crucial nutrient reservoir of phosphorus that is available to organisms.

Accepted Answer

Rocks are a crucial nutrient reservoir of phosphorus, as phosphorus is released from rocks through weathering processes and becomes available to organisms.

Question 4

What is biological magnification?

Accepted Answer

Biological magnification refers to the process where toxic substances, such as pesticides or heavy metals, accumulate in living organisms and become more concentrated at each successive level of the food chain.

Question 5

Which trophic level has the LEAST biological magnification?

Accepted Answer

Primary producers have the least biological magnification because they are at the base of the food chain and do not consume other organisms, thus accumulating fewer toxins.

Question 6

Autotrophs gain energy from

Accepted Answer

Autotrophs are organisms that can produce their own food from inorganic nutrients and energy from the sun.

Question 7

Bacteria that live in deep- sea thermal vents use energy from inorganic hydrogen sulfide (H₂S) to make organic molecules from carbon dioxide and are thus

Accepted Answer

These bacteria are producers because they use chemosynthesis to convert inorganic molecules like hydrogen sulfide into organic molecules, similar to how plants use photosynthesis.

Question 8

Phosphorus, which is often a limiting nutrient in ecosystems, is important because it

Accepted Answer

Phosphorus is a critical component of ATP, cell membranes, and nucleic acids, which are essential for energy transfer, cellular structure, and genetic information in living organisms.

Question 9

Which of the following terms correctly describes carnivores?

Accepted Answer

Carnivores are called secondary consumers because they eat primary consumers, which are herbivores. Autotrophs are organisms that produce their own food, detritus consumers feed on dead organic matter, and consumer producers do not exist as a recognized ecological term.

Question 10

If a couple was attempting to get pregnant, which foods should they eat to avoid ingesting high amounts of toxins?

Accepted Answer

Organic grains, fruits, and vegetables are less likely to contain high levels of toxins compared to other options listed, such as high-level carnivores, DDT-treated vegetables, or meals microwaved in plastic bags.

Question 11

In open- water marine ecosystems, the occupy the same trophic level as the giant sequoias (redwoods) in the forests of California.

Accepted Answer

Phytoplankton, like giant sequoias, are primary producers that convert sunlight into energy through photosynthesis, occupying the same trophic level.

Question 12

Detritus feeders consume

Accepted Answer

Detritus feeders, also known as detritivores, primarily consume dead organic matter, which includes decomposing plant and animal parts as well as fecal matter.

Question 13

In a grassland of Kansas, 1,000 grams of grass are produced per square meter per year by all the different grass species. A theoretical upper limit to the biomass of secondary consumers that can be supported in this ecosystem is

Accepted Answer

The theoretical upper limit to the biomass of secondary consumers that can be supported in this ecosystem is 10% of the primary production, which is 100 grams.

Question 14

Which of the following components is NOT involved in the phosphorus cycle?

Accepted Answer

The atmosphere is not involved in the phosphorus cycle.

Question 15

The three major reservoirs of carbon are

Accepted Answer

The three major reservoirs of carbon are the oceans, the atmosphere, and fossil fuels.

Question 16

Net primary production is

Accepted Answer

Net primary production is the energy that photosynthetic organisms (autotrophs) make available to other organisms (heterotrophs) over a given period of time, after accounting for the energy used in their own respiration.

Question 17

If you are attempting to minimize the amount of mercury in your diet, you should eat

Accepted Answer

Producers such as fruits and vegetables do not accumulate mercury like animals higher up the food chain, making them a safer choice for minimizing mercury intake.

Question 18

The community of detritivores, such as earthworms, millipedes, slugs, and pseudoscorpions, living in the leaf litter on the shady floor of a deciduous forest obtains its energy and nutrients primarily from

Accepted Answer

Detritivores obtain their energy and nutrients from the decomposition of organic matter, such as the leaves of deciduous trees that fall on the forest floor.

Question 19

Oceans, the atmosphere, and fossil fuels are large reservoirs of

Accepted Answer

Oceans, the atmosphere, and fossil fuels are large reservoirs of carbon, which is a key component of the carbon cycle.

Question 20

A snake that eats a small rabbit that feeds on grass is classified as a(n)

Accepted Answer

A snake that eats a rabbit is a secondary consumer because it feeds on a primary consumer (the rabbit), which in turn feeds on a primary producer (grass).

Quiz 29: Energy Flow and Nutrient Cycling in Ecosystems