Question

Giving two examples, justify the statement that the sex of the offspring in all animals is not always genetically determined.

Answer 1

Temperature-dependent sex determination in reptiles:

• In some reptiles, such as crocodiles and many turtles, the incubation temperature determines the sex of the offspring.
• For example, in some turtles, eggs incubated at higher temperatures produce females, while those incubated at lower temperatures produce males.

Environmental sex determination in some fish:

• In some fish species, such as clownfish, sex is determined by social environment rather than genetics.
• Clownfish are born male and can change to female if the dominant female in the group dies.

These examples show that sex determination is not always genetically fixed.