Question

"Sex of a newborn baby in humans depends on the father, not the mother." Confirm this statement with the help of a flow chart.

Hint:

Only the father contributes the sex-determining chromosome (X or Y), so the baby's sex is decided by the father.

Answer 1

In humans, sex is determined by sex chromosomes. Males have XY chromosomes and females have XX chromosomes. During reproduction: \[ \text{Mother (XX)} \Rightarrow \text{Provides X chromosome only}
\text{Father (XY)} \Rightarrow \text{Can provide either X or Y chromosome} \] Flow chart: \[ \begin{array}{c} \text{Mother (X)}
\downarrow
\text{Father (X or Y)} \Rightarrow \begin{cases} \text{X from father} \Rightarrow \text{XX (Girl)}
\text{Y from father} \Rightarrow \text{XY (Boy)} \end{cases} \end{array} \] So, the child's sex depends on whether the sperm carries an X or Y chromosome — determined by the father.