Why do female mosquitoes require a blood meal in relation to egg development?

Why do female mosquitoes require a blood meal in relation to egg development?

• A. Blood provides proteins for vitellogenesis; digestion initiates gonotrophic cycle, leading to egg maturation and oviposition.
• B. Blood is used primarily for hydration and has no role in egg development.
• C. Blood meal activates wing muscles for flight adjustments.
• D. Blood meal detoxifies ingested toxins.

Answer: (A)

The key idea is that egg development in many female mosquitoes depends on the nutrients from a blood meal. The blood provides amino acids needed to synthesize vitellogenin, the yolk protein that fills and nourishes developing eggs. After the blood is digested, these nutrients trigger hormonal signals that start the gonotrophic cycle, promoting oocyte growth, uptake of yolk proteins into the ovaries, egg maturation, and eventual oviposition. Without a blood meal, there aren’t enough proteins to form the yolk, so egg development stalls—even though a sugar meal can supply energy, it can’t substitute for the protein needs of vitellogenesis. The other ideas don’t explain why blood is needed for eggs: hydration isn’t the reproductive driver, wing muscles aren’t activated to enable reproduction, and detoxification isn’t the purpose of supplying blood for egg development.

The key idea is that egg development in many female mosquitoes depends on the nutrients from a blood meal. The blood provides amino acids needed to synthesize vitellogenin, the yolk protein that fills and nourishes developing eggs. After the blood is digested, these nutrients trigger hormonal signals that start the gonotrophic cycle, promoting oocyte growth, uptake of yolk proteins into the ovaries, egg maturation, and eventual oviposition. Without a blood meal, there aren’t enough proteins to form the yolk, so egg development stalls—even though a sugar meal can supply energy, it can’t substitute for the protein needs of vitellogenesis. The other ideas don’t explain why blood is needed for eggs: hydration isn’t the reproductive driver, wing muscles aren’t activated to enable reproduction, and detoxification isn’t the purpose of supplying blood for egg development.