Statement I is false but Statement II is true
Hymenoptera use arrhenotokous parthenogenesis where drones (males) develop from unfertilized eggs, while queens and workers develop from fertilized eggs.
Statement I correctly highlights parthenogenesis’s role in eusocial organization; Statement II reverses the reproductive modes.
Question Breakdown
Statement I is true: Parthenogenesis (specifically arrhenotoky) determines sex ratios and caste genetics in Hymenoptera colonies, enabling haplodiploidy where sisters are more related than mother-daughter (r=0.75 vs 0.5), favoring worker sterility. Statement II is false: In honeybees, drones arise parthenogenetically (haploid, unfertilized), while diploid queens/workers require fertilization—opposite of the claim.
Option Analysis
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Both true: Incorrect. II misstates bee reproduction.
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Both false: Wrong. I fundamental to eusociality.
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Statement I true, Statement II false: Correct answer. Classic haplodiploidy question.
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Statement I false, Statement II true: False. Parthenogenesis central to social insect evolution.
Correct Answer
Statement I is true but Statement II is false.
Hymenoptera Haplodiploidy System
Parthenogenesis plays important role in social organization of bee/wasp/ant colonies via arrhenotoky: unfertilized eggs → haploid males (drones); fertilized → diploid females (queens/workers). This 3:1 sister relatedness drives eusociality per Hamilton’s rule.
Statement I: Evolutionary Driver
Parthenogenesis enables queen control of colony sex ratio (3:1 female:male optimal) and worker policing of reproduction. Cape honeybee shows worker thelytoky (clonal females), but standard system matches I perfectly.
Statement II: Reversed Reality
In bees, large number of males (drones) ARE produced parthenogenetically (haploid n); sterile female workers and queens sexually (2n, fertilized). Statement claims opposite—workers parthenogenetic, drones sexual (impossible in arrhenotoky).
| Caste |
Ploidy |
Fertilization |
Parthenogenesis? |
| Drones |
Haploid |
No |
Yes |
| Workers |
Diploid |
Yes |
No |
| Queens |
Diploid |
Yes |
No |
Exam Strategy
NEET/GATE mnemonic: “Drones Partheno, Queens Fertile”. Statement I = kin selection foundation; II = distractor flipping haploid/diploid. Haplodiploidy explains eusociality in Hymenoptera but not termites/Isoptera.
Essential for your entomology and evolutionary biology prep.
