Q1. After hatching by the hen, the young chicks come out of eggs within
(a) One week
(b) Two weeks
(c) Three weeks
(d) Four weeks
(UPSC Prelims 1979)
Answer: (c) Three weeks
Explanation: The incubation period for hen eggs is typically around 21 days, or three weeks, during which the embryo develops inside the egg. After this period, the chicks hatch naturally, provided the temperature and humidity are optimal.
Q2. Which one of the following is a fast growing tree ?
(a) Teak
(b) Eucalyptus
(c) Banyan
(d) Coconut
(UPSC Prelims 1979)
Answer: (b) Eucalyptus
Explanation:
Eucalyptus is known for its rapid growth rate, making it ideal for timber, pulpwood, and reforestation projects. It can reach maturity quickly, often within a few years, and is widely planted for commercial forestry.
Q3. Feeding of milk cattle with cotton seeds
(a) Increases fat content temporarily
(b) Decreases fat content temporarily
(c) May decrease or increase fat content
(d) Causes no change in fat content
(UPSC Prelims 1979)
Answer: (a) Increases fat content temporarily
Explanation:
Cotton seeds are rich in oil and protein, and when fed to milch cattle, they can temporarily boost the fat content in milk. This effect is due to the high energy content of the seeds, which influences milk composition.
Q4. Which of the following can be said as the “Theory of Darwin”
(a) Survival of the fittest and struggle for existence
(b) Weak and strong always maintain a fixed proportion
(c) Different species do not arise by genetic mutation
(d) None of these
Answer: (a) Survival of the fittest and struggle for existence
Explanation: Charles Darwin’s theory of evolution emphasizes natural selection, where organisms best adapted to their environment survive and reproduce. This concept of “survival of the fittest” and “struggle for existence” explains how species evolve over time.
Q5. Pearls are formed inside
(a) Squids
(b) Snails
(c) Oysters
(d) Mollusks
(UPSC Prelims 1982)
Answer: (c)
Explanation: Pearls are formed inside oysters when an irritant enters the shell. The oyster secretes nacre, a smooth substance, around the irritant, gradually forming a pearl. This is a natural defense mechanism.
Q6. The best conceiving season for cows and buffaloes is
(a) Summer
(b) Winter
(c) Spring
(d) There is no definite relationship between conceiving and season
(UPSC Prelims 1982)
Answer: (d)
Explanation: There is no fixed seasonal pattern for the conception of cows and buffaloes. Their reproductive cycles depend more on nutrition, health, and management practices than on seasonal changes.
Q7. The most preferential poultry feed is
(a) Maize
(b) Barley
(c) Wheat
(d) Rice husk
(UPSC Prelims 1982)
Answer: (d)
Explanation: Rice husk, though not nutritionally rich, is often used as a cost-effective poultry feed. However, in practice, maize is typically preferred for its high energy content, but the answer key indicates rice husk as the correct choice.
Q8. Gerontology is the study of
(a) Process of ageing
(b) Growth of cells
(c) Birds
(d) Vegetables
(UPSC Prelims 1983)
Answer: (a) Process of ageing
Explanation: Gerontology is the scientific study of ageing, focusing on the biological, psychological, and social aspects of growing older. It helps in understanding age-related changes and improving elderly care and quality of life.
Q9. For artificial insemination the semen of a bull should be stored in
(a) Cold water
(b) Ice
(c) Liquid nitrogen
(d) Liquid oxygen
(UPSC Prelims 1983)
Answer: (c) Liquid nitrogen
Explanation: Liquid nitrogen is used to store bull semen at extremely low temperatures, preserving its viability for artificial insemination. It prevents cell damage and maintains fertility over long periods.
Q10. Gestation period of a goat is about
(a) 150 days
(b) 200 days
(c) 250 days
(d) 365 days
(UPSC Prelims 1984)
Answer: (a) 150 days
Explanation: The gestation period of a goat is approximately 150 days, or about 5 months. This duration allows for the development of the fetus before birth and is important for livestock management and breeding cycles.
Q11. Arrange the following in descending order of their life spans :
A. Elephant
B. Horse
C. Tiger
D. Wolf
(a) A, B, C, D
(b) A, C, B, D
(c) C, A, B, D
(d) D, A, B, C
(UPSC Prelims 1984)
Answer: (b) A, C, B, D
Explanation:
In terms of average life span:
- Elephant: ~60–70 years
- Tiger: ~20–25 years
- Horse: ~25–30 years
- Wolf: ~10–14 years
Thus, the correct descending order is Elephant, Tiger, Horse, Wolf.
Q12. Sex of a child is determined by the
(a) Chromosomes of father
(b) Chromosomes of mother
(c) Rh factor of parents
(d) None of these
Answer: (a) Chromosomes of father
Explanation: The father’s chromosomes determine the sex of the child. Males have XY chromosomes, while females have XX. The sperm can carry either an X or Y chromosome, and when it fertilizes the egg (which always carries X), the combination XY results in a male and XX in a female.
Q13. Which pair is correct?
(a) Sea horse, Sea cucumber, Sea urchin
(b) Star fish, Cuttle fish, Dog
(c) House fly, Dragon fly, Butterfly
(d) Earthworm, Ringworm, Tapeworm
(UPSC Prelims 1984)
Answer: (c) House fly, Dragon fly, Butterfly
Explanation: All three—house fly, dragon fly, and butterfly—are insects, sharing characteristics like three-part body structure, six legs, and exoskeletons. The other options mix invertebrates from different phyla, making them incorrect pairs.
Q14. Which of the following statements about “Dinosaurs” is/are correct ?
(a) The early man was a contemporary of Dinosaurs
(b) Man appeared first after the Dinosaurs became extinct
(c) The Dinosaurs became extinct about six million years before the appearance of the first man on the earth
(d) The Dinosaurs became extinct about 200 million years before the first man appeared on the earth
(UPSC Prelims 1985)
Answer: (d) The Dinosaurs became extinct about 200 million years before the first man appeared on the earth
Explanation: Dinosaurs became extinct approximately 65 million years ago, while modern humans appeared only about 200,000 years ago. This means there is a vast time gap between the extinction of dinosaurs and the emergence of humans, making them non-contemporaries.
Q15. Which of the following is a living fossil ?
(a) Blue green algae
(b) Green algae
(c) Fungus
(d) Ginkgo
(UPSC Prelims 1987)
Answer: (d) Ginkgo
Explanation: Ginkgo biloba is considered a living fossil because it has remained unchanged for millions of years, surviving while other related species became extinct. It represents an ancient lineage of plants.