Question

Which of the following statements are true with reference to the sex-determination in honeybees?
A. An offspring formed from the union of a sperm and an egg develops as a female (queen or worker).
B. An unfertilized egg develops as a male by parthenogenesis.
C. A male has half the number of chromosomes than that of a female.
D. Males produce sperms by meiosis.
E. Honeybees have a haplodiploid sex-determination system.

• A. A, B, C and E only
• B. B, C, D and E only
• C. A, B, C and D only
• D. A, B, D and E only

Hint:

To remember why drones use mitosis: They are already at the "halfway point" ($n$). If they did meiosis, they'd have "half-a-set" of instructions, which doesn't work! Male Honeybees = Mitosis.

Answer 1

The Correct Option is A

Honeybees exhibit a fascinating genetic mechanism for sex determination known as the haplodiploid system. This system ensures a specific social structure within the hive based on chromosomal count. The detailed breakdown of these biological processes is as follows:
• Female Development (Diploid): Females, which include both the fertile Queen and the sterile Workers, are produced through sexual reproduction. When a sperm fertilizes an egg, the resulting zygote has a complete set of 32 chromosomes ($2n = 32$).
• Male Development (Haploid): Males, known as Drones, are produced via arrhenotokous parthenogenesis. This means they develop directly from unfertilized eggs laid by the queen. Consequently, they possess only 16 chromosomes ($n = 16$), which is exactly half the female count.
• Spermatogenesis in Drones: Since males are already haploid ($n$), they cannot undergo a reductional division (meiosis) to produce gametes. Therefore, they produce sperm through mitosis. Statement D is incorrect because it claims they use meiosis.
• Kinship Consequences: Because of this system, drones have no father and cannot have sons, but they do have a grandfather and can have grandsons. Since statements A, B, C, and E are scientifically accurate and statement D is false, option (a) is the only correct choice.