Question

Larva of Bonellia settling near proboscis of adult female develops into male due to.

• A. Substances secreted by proboscis
• B. Electrolytes in water
• C. Oxygen in environment
• D. Carbon dioxide in environment

Answer 1

The correct option is A Substances secreted by proboscis

Baltzer showed that if a Bonellia larva settles on the seafloor, it becomes a female. However, should a larva land on a female's proboscis (which apparently emits chemical signals that attract the larva), it enters the female's mouth, migrates into her uterus, and differentiates into a male. Thus, if a larva lands on the seafloor, it becomes female; if it settles on a proboscis, it becomes male.

So, the correct answer is 'Substances secreted by proboscis'.