EVERYDAY SCIENCE

Detailed explanation-1: -So, from the options given, it is Bonellia in which sex is determined by external environmental factors.

Detailed explanation-2: -While the sex of most snakes and most lizards is determined by sex chromosomes at the time of fertilization, the sex of most turtles and all species of crocodilians is determined by the environment after fertilization.

Detailed explanation-3: -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.

Detailed explanation-4: -Environmental factors which often influence sex determination during development or sexual maturation include light intensity and photoperiod, temperature, nutrient availability, and pheromones emitted by surrounding plants or animals.