Pre AP Biology -ECO 3.2 Types of Ecological Communities- MCQ Exam Style Questions -New Syllabus

Pre AP Biology -ECO 3.2 Types of Ecological Communities- MCQ Exam Style Questions – New Syllabus 2025-2026

Pre AP Biology -ECO 3.2 Types of Ecological Communities- MCQ Exam Style Questions – Pre AP Biology – per latest Pre AP Biology Syllabus.

Pre AP Biology – MCQ Exam Style Questions- All Topics

Question

Which of these statements refers to the equilibrium theory of island biogeography prediction about the number of species found on an island?

a. The number of species found on an island increases steadily until it equals the number in the mainland species pool.

b. The number of species found on an island is greater on large islands than on small ones.

c. The number of species found on an island is smaller on islands near the mainland than on distant islands.

d. The number of species found on an island is greater for islands near the equator than for islands near the poles.

▶️ Answer/Explanation

Detailed solution

The correct option is b.

The theory states that species richness reaches an equilibrium ($S$) where immigration rates equal extinction rates.
Larger islands provide more resources and diverse habitats, which significantly reduces the extinction rate ($E$).
Because of lower extinction, large islands can support a higher equilibrium number of species than small islands.
Distance also plays a role, where islands closer to the mainland have higher immigration rates ($I$) than distant ones.
Therefore, the highest biodiversity is predicted for large islands located near the mainland.
Option a is incorrect because islands rarely reach the full mainland species count due to distance and area constraints.

Question

Which of the following differentiates a species habitat from its ecological niche?

A. A habitat is where a species lives, including the range of environmental factors in that area, whereas a species ecological niche is the role, job, or way of life for obtaining resources.

B. A habitat is the diet a species eats, including the range of foods available in the area it lives, whereas a species ecological niche is how competition leads to a changing environment.

C. A habitat is the ability of a species to survive and reproduce, whereas a species ecological niche is where a species lives, including the range of environmental factors in that area.

D. A habitat is the role, job, or way of life for obtaining resources, whereas a species ecological niche is where a species lives, including the range of environmental factors in that area.

▶️ Answer/Explanation

Detailed solution

The correct option is A.
A habitat is defined as the physical location or “address” where an organism resides.
It encompasses all abiotic factors like climate, soil, and water available in that specific area.
An ecological niche refers to the “profession” or functional role of the species within its ecosystem.
This includes how it interacts with other species and how it utilizes available energy and resources.
Option D is incorrect because it swaps the definitions of habitat and niche.
Options B and C provide incomplete or inaccurate descriptions of these biological concepts.

Question

Cholera is an intestinal infection that causes severe vomiting, diarrhoea, dehydration and, if not treated promptly, death. It is transmitted when people ingest water or food contaminated with cholera bacteria.

What is the most appropriate prevention strategy?

(A) Treat infected patients with antibiotics to prevent them from developing cholera in future exposures to the bacterium.

(B) Vaccinate the cholera patient to kill the bacteria by destroying their cell wall.

(D) Treat the cholera-infected main water source with chlorine to kill the cholera bacterium.

▶️ Answer/Explanation

Detailed solution

Correct Option: (D)
Prevention strategies aim to stop the spread of a pathogen before it infects a host.
Chlorinating water sources kills $Vibrio$ $cholerae$ bacteria, breaking the transmission cycle.
Option (A) is incorrect as antibiotics treat current infections but do not provide long-term immunity.
Option (B) is incorrect because vaccines stimulate immune memory, they do not directly destroy bacterial cell walls.
Option (C) describes a treatment (Oral Rehydration Therapy) for symptoms, not a prevention strategy.
Therefore, disinfecting the water supply is the most effective way to prevent a population-level outbreak.

Pre AP Biology -ECO 3.2 Types of Ecological Communities- MCQ Exam Style Questions -New Syllabus