Which of the following structures is identical in monozygotic twins?

$A$ diseased man marries a normal woman and they get three daughters and five sons. All the daughters were diseased and sons were normal. The gene of this disease is

Which one of the following is a genetically transmitted character?

The color of mashed fruit (or fruit skin color in certain varieties) is an example of ........

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?

In a certain plant species,red flower colour is incompletely dominant to white flower colour (the heterozygote is pink) and tall stems are completely dominant to dwarf stems. If a tall pink plant $(TtRr)$ is crossed with a tall white plant $(TTrr)$,which one of the following types of plants would be produced in the offspring?