Q1. Consider the following statements about seed dormancy and migration:
- Seed dormancy → temporary halting of germination
- Seasonal migration → temporary movement of organisms from habitat
How many pairs are correctly matched?
(a) Only one
(b) Only two
(c) Only three
(d) All four
Answer: (b) Only two
Explanation:
- Both seed dormancy and seasonal migration definitions are correctly matched.
Q2. Which of the following are components of the detritus food chain?
- Decomposers (bacteria, fungi)
- Detritivores (earthworms, dung beetles)
- Primary producers (plants)
(a) 1 and 2 only
(b) 1 and 3 only
(c) 2 and 3 only
(d) All three
Answer: (a) 1 and 2 only
Explanation:
- Detritus food chain involves dead organic matter, detritivores, and decomposers, not primary producers.
Q3. Consider the statements regarding ecological pyramids:
- Pyramid of energy is always upright.
- Pyramid of biomass may be inverted in aquatic ecosystems.
- Pyramid of numbers is always upright.
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) All three
Answer: (a) 1 and 2 only
Explanation:
- Pyramid of energy → always upright.
- Pyramid of biomass → can be inverted in aquatic systems.
- Pyramid of numbers → can be upright or inverted depending on producers/consumers.
Q4. Which of the following statements about nutrient cycling are correct?
- Carbon cycle involves exchange between atmosphere, biosphere, and lithosphere.
- Nitrogen fixation converts N2 to NH3 by free-living bacteria.
- Phosphorus cycle does not have an atmospheric component.
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) All three
Answer: (d) All three
Explanation:
- Carbon → cycles through air, water, soil, and organisms.
- Nitrogen → N2 converted to ammonia by nitrogen-fixing bacteria.
- Phosphorus → primarily lithosphere-soil-water; no gaseous phase.
Q5. Consider the following statements regarding ecological niches:
- Fundamental niche → full potential range without competition.
- Realized niche → actual range occupied due to competition and predation.
(a) Both correct
(b) Both incorrect
(c) Only 1 correct
(d) Only 2 correct
Answer: (a) Both correct
Explanation:
- Fundamental vs realized niche → classic ecological concept introduced by Hutchinson.
