Question

How is the sex of a newborn individual determined in different species of animals? Give three examples to support your answer.

Answer 1

The sex of a newborn individual is determined by various mechanisms across different species, and here are three examples:

1. Temperature-Dependent Sex Determination: In some reptiles, such as certain species of turtles and crocodiles, the temperature at which fertilized eggs are incubated can determine the sex of the offspring. For instance, higher temperatures might lead to a majority of male offspring, while lower temperatures might lead to female offspring.

2. Sex Change in Response to Environmental Cues: Some animals, like certain species of fish and snails, are capable of changing their sex during their lifetime. This indicates that their sex determination isn't strictly genetic and can be influenced by environmental factors or the needs of their population.

3. Genetic Sex Determination in Humans: In humans, the sex of an individual is largely genetically determined. Humans have one pair of sex chromosomes which are either two X chromosomes in females (XX) or one X and one Y chromosome in males (XY). The sex chromosome that a child inherits from the father determines their sex: an X chromosome from the father results in a girl, while a Y chromosome from the father results in a boy​.