On the basis of Mendel's work,which of the following laws were formulated?
$I.$ Linkage
$II.$ Segregation
$III.$ Incomplete dominance
$IV.$ Independent assortment
Choose the correct option.

Which one of the following symbols and its representation,used in human pedigree analysis,is correct?

Which of the following statements is correct?

Which of the following statements are incorrect? $(i)$ $ABO$ blood grouping is controlled by gene $I$. (ii) Gene $I$ has four alleles. (iii) $I^A$ and $I^B$ produce the same type of sugar. (iv) $I$ or $i$ produces a different type of sugar. $(v)$ $I^A$ and $I^B$ are incompletely dominant.

Which of the following statements are correct?
$i$. $X$ chromosome has a large amount of euchromatin.
$ii$. Heterochromatin is genetically inert.
$iii$. Both $X$ and $Y$ chromosomes are homologous.
$iv$. Crossing over does not take place in sex chromosomes in females.
Choose the correct option.

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?