Question 1

Which of the following best describes the difference between a habitat and a niche?

Accepted Answer

A habitat is the physical place an organism lives, while a niche is the organism's role and interactions within its environment.

Question 2

In a savanna ecosystem, lions and hyenas both hunt similar prey. What ecological concept does this scenario best illustrate?

Accepted Answer

Interspecific competition

Question 3

Which of the following is an example of mutualism?

Accepted Answer

Clownfish living among sea anemone tentacles, where both species benefit

Question 4

Which of the following best describes the relationship between heartworms and dogs?

Accepted Answer

Parasitism, because the heartworm benefits while the dog is harmed

Question 5

Which of the following is the best example of commensalism?

Accepted Answer

Cattle egrets eating insects stirred up by cattle, while the cattle are unaffected

Question 6

Which of the following best explains why food chains rarely exceed four or five trophic levels?

Accepted Answer

Only about 10% of energy is transferred from one trophic level to the next, limiting the energy available at higher levels.

Question 7

Which equation best represents the law of 10% for energy transfer between trophic levels?

Accepted Answer

$$E_{n+1} = 0.1 	imes E_n$$

Question 8

A toxin is introduced at the producer level of a food chain. What is the most likely outcome for organisms at higher trophic levels?

Accepted Answer

The concentration of the toxin will increase at higher trophic levels due to biomagnification.

Question 9

Which of the following best describes the role of decomposers in an ecosystem?

Accepted Answer

They break down dead and decaying matter, recycling nutrients back into the ecosystem.

Question 10

If a population of prey increases, what is the most likely short-term effect on the predator population according to predator-prey dynamics?

Accepted Answer

The predator population will increase after a short lag period.

Question 11

Which of the following is an example of interspecific competition?

Accepted Answer

A lion and a leopard fighting over the same prey animal

Question 12

Which of the following best describes the realized niche of a species?

Accepted Answer

The actual role and space a species occupies due to competition with other species

Question 13

Which of the following is a correct sequence of trophic levels in a typical food chain?

Accepted Answer

Producer → Primary Consumer → Secondary Consumer → Tertiary Consumer

Question 14

Which of the following best explains why vegetarians can be supported in greater numbers than meat-eaters in terms of energy flow?

Accepted Answer

Vegetarians consume food at a lower trophic level, where more energy is available.

Question 15

Which of the following is an example of bioaccumulation?

Accepted Answer

A fish gradually accumulating mercury in its tissues over its lifetime

Question 16

Which of the following best describes the direction of energy flow in an ecosystem?

Accepted Answer

From the sun to producers to consumers to decomposers

Question 17

Which of the following is a likely consequence of two species occupying the same niche in the same habitat?

Accepted Answer

One species will outcompete the other, leading to competitive exclusion.

Question 18

Which of the following is NOT a type of symbiotic relationship?

Accepted Answer

Predation

Question 19

If a pyramid of biomass shows a much smaller mass at the tertiary consumer level compared to the producer level, what is the best explanation?

Accepted Answer

Energy and matter are lost at each trophic level, supporting fewer organisms at higher levels.

Ecological Relationships and Energy Flow in Ecosystems

Study Guide - Practice Questions