Q1.. Consider the following statements regarding Plankton:
- Planktons, though they can swim for hundreds of kilometres per day, depend on other organisms for movement.
- They contribute more than half of the oxygen in the environment.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer: (b) 2 only
- S1 — Incorrect
Plankton cannot swim long distances; they are drifters moved by currents. Only some zooplankton show limited locomotion. - S2 — Correct
Phytoplankton contribute ~50–60% of global oxygen production through photosynthesis.
Q2.. Which of the following is correct regarding “Phytoplankton”?
Statement-I: Phytoplankton can be found at the bottom of water.
Statement-II: Chemosynthesis is the process by which food is made by bacteria or other living things using chemicals as the energy source, typically in the absence of sunlight.
Which one of the following is correct in respect of the above statements?
(a) Both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I
(b) Both Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-I
(c) Statement-I is correct but Statement-II is incorrect
(d) Statement-I is incorrect but Statement-II is correct
Answer: (d) Statement-I is incorrect but Statement-II is correct
- S1 — Incorrect
Phytoplankton occur in the sunlit (euphotic) upper layer, not at the bottom. - S2 — Correct
Chemosynthesis = food production using chemical energy in absence of sunlight (deep-sea bacteria).
Q3.. With respect to Seagrass, which of the following are incorrect?
- They are found in coastal waters of all continents except Antarctica
- In India, they are found only in the Palk Strait and Gulf of Mannar
- Seagrasses have no roots, stems, and leaves and produce flowers and seeds
Which of the statements given above is/are incorrect?
(a) 1 only
(b) 2 only
(c) 1 and 3
(d) 2 and 3
Answer: (d) 2 and 3
- S1 — Correct
Found on coasts of all continents except Antarctica. - S2 — Incorrect
In India, they occur in Palk Bay, Gulf of Mannar, Andaman & Nicobar, Lakshadweep, Gulf of Kachchh, Odisha, Kerala coasts. - S3 — Incorrect
Seagrasses are true flowering plants (angiosperms) with roots, rhizomes, leaves, flowers, and seeds.
Q4. Consider the following statements:
- All phytoplankton perform photosynthesis
- Some phytoplankton are fungi
- Phytoplankton do not consume other organisms
How many of the statements given above are correct?
(a) One statement only
(b) Two statements only
(c) Three statements only
(d) None of the above
Answer: (d) None of the above (zero statements correct)
- S1 — Incorrect
Not all phytoplankton are strictly photosynthetic — many dinoflagellates are mixotrophic. - S2 — Incorrect
Phytoplankton are algae + cyanobacteria, not fungi. - S3 — Incorrect
Some phytoplankton consume microorganisms (mixotrophy).
Q5.. Which of the following are uses of seaweeds?
- Biodegradation of methane
- Can be used as battery material for energy generation
- Cure for kidney disease
- Used as a drug for goitre treatment
- Habitat for fish breeding ground
Which of the statements given above are correct?
(a) 1, 2, 3 and 5
(b) 2, 3, 4 and 5
(c) 1, 2, 4 and 5
(d) 1, 2, 3, 4 and 5
Answer: (c) 1, 2, 4 and 5
- 1 — Correct
Seaweed-based systems are explored for methane mitigation/biodegradation in environmental research. - 2 — Correct
Seaweed-derived alginate & carbon materials used in battery electrodes/energy storage. - 3 — Incorrect
No established medical evidence of a cure for kidney disease. - 4 — Correct
Rich in iodine — historically used in goitre treatment. - 5 — Correct
Forms nursery & breeding habitats for marine fish.
