$\mathrm{C}$-value is the characteristic $\mathrm{DNA}$ content in a haploid cell of a given species. Earlier it was considered that $\mathrm{C}$-value correlates with organism complexity. However, it is now evident that $\mathrm{C}$-value varies enormously among species and that this bears no correlation with the complexity of the organisms. For example, the cells of some salamanders may contain $40$ times more $\mathrm{DNA}$ than those of humans. Which of the following explains this $C$-value paradox?

The $\mathrm{DNA}$ fingerprinting analysis of four family members is shown below.

Study the band pattern obtained and assign each family member to $\mathrm{W}, \mathrm{X}, \mathrm{Y}$ and $Z$. Choose the correct option.

The semi-conservative nature of $\mathrm{DNA}$ replication was established by Meselson and Stahl in their classic experiment with bacteria. They grew bacteria in ${\mathrm{N}}^{15}$. ${\mathrm{NH}}_4\mathrm{Cl}$ containing medium, washed and then incubated in fresh medium with ${\mathrm{N}}^{14}$- containing compounds and allowed to grow for three generations. $\mathrm{CsCl}$ density gradient centrifugation of isolated $\mathrm{DNA}$ established the nature of semiconservative $\mathrm{DNA}$ replication. The pictorial representation below shows the position of differentially labeled $\mathrm{DNA}$ in $\mathrm{CsCl}$ density gradient.

Had the $\mathrm{DNA}$ replication been conservative, what would have been the pattern?

A $\mathrm{DNA}$ sequence undergoes three subsequent point mutations which result in subsequent changes in transcription of $\mathrm{mRNA}$ as shown below:
Original $\mathrm{mRNA} :\mathrm{AUG} \mathrm{CAU} \mathrm{CUC} \mathrm{ACG} \mathrm{GAU} \mathrm{UAG}$

Point mutation $1 : \mathrm{AUG} \mathrm{CAU} \mathrm{CUU} \mathrm{ACG} \mathrm{GUA} \mathrm{UAG}$

Point mutation $2 : \mathrm{AUG} \mathrm{CAU} \mathrm{GCU} \mathrm{UAC} \mathrm{GGU} \mathrm{AUA}$

Point mutation $3 : \mathrm{AUG} \mathrm{CAU} \mathrm{GCU} \mathrm{UAA} \mathrm{GGU} \mathrm{AUA}$

Select the correct sequence of point mutations that occurred in the $\mathrm{DNA}$.