UPSC Prelims 1995 · General Studies
Question 121: Science and Technology
Which one of the following is a membrane that protects the developing embryo from desiccation?
AnswerThe answer is (a).
The amnion is the thin membrane that surrounds the embryo and holds the amniotic fluid, protecting it from drying out and from shocks. The allantois helps in respiration and excretion in birds and reptiles and forms part of the placenta in mammals; the chorion lies outside, helping gas exchange and nourishment; the yolk sac stores food. Remember: amnion protects, allantois excretes, chorion exchanges, yolk sac feeds.
Why each option is right or wrong
- (a) Right: the amnion.
- (b) The allantois deals with respiration and waste, not protection against drying.
- (c) The chorion is the outer membrane for gas exchange and nourishment.
- (d) The yolk sac holds food, not the protective fluid.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 1995, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.