Select the incorrect statement:

The father has blood group $AB$ and the mother has blood group $O$. Which of the following blood groups can the child have?

In a plant,three dominant genes $A$,$B$,and $C$ must be expressed together to produce purple flowers. If any one or all three genes are in the recessive state,the flowers become colorless.
Raw material $\xrightarrow{A} X \xrightarrow{B} Y \xrightarrow{C} Z$ (Pigment)
$A$ purple-flowered plant with genotype $AABBCC$ is crossed with a colorless plant with genotype $aabbcc$. This results in $F_1$ hybrid purple offspring. What will be the proportion of purple-flowered plants in the $F_2$ generation produced by selfing the $F_1$ generation?

Differences in twins suggest

In sickle cell anaemia$-$

Match the following pairs based on the sex determination mechanism shown in the table:

	Male $(♂)$	Female $(♀)$
$x$	$XY$	$XX$
$y$	$ZZ$	$ZW$