CLEP Biology Ecology & Evolutionary Processes 5 — Questions and Answers
Question 1: Which ecological term describes the role and position of a species in its environment, including its diet, habitat, and interactions?
- Habitat
- Ecological niche (Correct answer)
- Biome
- Guild
Correct answer: Ecological niche
An ecological niche encompasses all the biotic and abiotic conditions a species needs to survive and reproduce, as well as its functional role in the ecosystem.
Question 2: The bottleneck effect is an example of genetic drift that occurs when:
- A small group colonizes a new habitat
- A large population is drastically reduced by a catastrophic event (Correct answer)
- Two populations exchange genes through migration
- A mutation spreads rapidly through a large population
Correct answer: A large population is drastically reduced by a catastrophic event
The bottleneck effect occurs when a population is sharply reduced by a catastrophe, leaving a small survivor group whose allele frequencies may differ greatly from the original population.
Question 3: In lake ecosystems, the euphotic zone is defined as the area where:
- Decomposition rates are highest
- Photosynthesis can occur due to sufficient light penetration (Correct answer)
- Water temperature is lowest
- Dissolved oxygen is absent
Correct answer: Photosynthesis can occur due to sufficient light penetration
The euphotic (photic) zone is the sunlit upper layer of a body of water where light is sufficient for photosynthesis to exceed respiration.
Question 4: Sexual selection that gives one sex an advantage in competing for mates of the other sex is called:
- Intrasexual selection (Correct answer)
- Intersexual selection
- Stabilizing selection
- Frequency-dependent selection
Correct answer: Intrasexual selection
Intrasexual selection involves direct competition between members of the same sex (usually males) for access to mates, often producing weapons like antlers or horns.
Question 5: Which type of interspecific interaction harms both species involved?
- Mutualism
- Commensalism
- Predation
- Competition (Correct answer)
Correct answer: Competition
Interspecific competition negatively affects both species because they consume the same limited resources, reducing the fitness of each compared to living without the other.
Question 6: Which evidence most directly supports the theory of evolution by natural selection?
- The fossil record showing species change over time (Correct answer)
- The fact that all organisms use ATP
- The universality of the genetic code
- DNA replication occurring in all cells
Correct answer: The fossil record showing species change over time
The fossil record provides a chronological history of life on Earth, showing gradual change in species over time and the appearance and extinction of lineages consistent with natural selection.
Question 7: The process of eutrophication in aquatic ecosystems refers to:
- Excessive algae growth due to nutrient enrichment, leading to oxygen depletion (Correct answer)
- The natural turnover of water layers in a lake
- Increased species diversity following pollution removal
- The acidification of water due to acid rain
Correct answer: Excessive algae growth due to nutrient enrichment, leading to oxygen depletion
Eutrophication occurs when excess nutrients (especially nitrogen and phosphorus) fuel algal blooms; when the algae die and decompose, oxygen is depleted, creating dead zones.
CLEP Biology Ecology & Evolutionary Processes 5
Which ecological term describes the role and position of a species in its environment, including its diet, habitat, and interactions?