Question

Given below are two statements:
Statement (I): Many female hymenopteran reproduce Arrehenotokously. Mothers are able to manipulate the sex of each progeny during oviposition by regulating the fertilization, sons develop parthenogenically by unfertilised eggs
Statement (II): Many female hymenopteran reproduce Arrehenotokously. Mothers are able to manipulate the sex of each progeny during oviposition by regulating the fertilization, daughters develop by fertilised diploid eggs
In light of the above statements, choose the most appropriate answer from the options given below:

• A. Both Statement (I) and Statement (II) are correct.
• B. Both Statement (I) and Statement (II) are incorrect.
• C. Statement (I) is correct but Statement (II) is incorrect.
• D. Statement (I) is incorrect but Statement (II) is correct.

Hint:

Remember:
- Unfertilized Egg = Haploid Male (Arrhenotoky)
- Fertilized Egg = Diploid Female
This haplodiploid system explains the unique social evolution and high relatedness among female workers in social Hymenoptera.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Haplodiploidy is a sex-determination system common in the order Hymenoptera (bees, ants, and wasps).
Under this system, sex is determined by the number of chromosome sets an individual receives.
Arrhenotoky is a specific form of parthenogenesis where unfertilized eggs develop into males.

Step 2: Detailed Explanation:
Let us analyze both statements:
Statement (I):
In Hymenoptera, adult females store sperm in an organ called the spermatheca after mating.
During egg-laying (oviposition), the female can control whether to release sperm to fertilize an egg as it passes down the oviduct.
If she restricts sperm release, the egg remains unfertilized.
These unfertilized eggs develop parthenogenetically into haploid, viable males (sons).
Thus, Statement I is correct.
Statement (II):
If the female opens the spermatheca, the egg is fertilized.
These fertilized eggs receive a chromosome set from both parents, developing into diploid females (daughters).
Depending on environmental cues or nutrition, these females become workers or queens.
This haplodiploid mechanism allows Hymenopteran mothers to adjust the sex ratio of their offspring based on resource availability or seasonal needs.
Thus, Statement II is also correct.
Both statements describe the two complementary halves of arrhenotokous haplodiploidy.

Step 3: Final Answer:
Both Statement I and Statement II are correct.
Thus, the correct choice is option 1.