The classical example of adaptive radiation in the development of new species is:

Consider the circle $x^2+y^2-4x-2y+c=0$ whose centre is $A(2,1)$. If the point $P(10,7)$ is such that the line segment $PA$ meets the circle at $Q$ with $PQ=5$,then $c$ is equal to

In $YDSE$, the separation between the slits is halved and the distance between the slit and the screen is doubled. The fringe width is

The reason for the double helical structure of $DNA$ is the operation of

$A$ satellite is launched into a circular orbit of radius $R$ around the Earth,while a second satellite is launched into an orbit of radius $1.02 R$. The percentage difference in the time periods of the two satellites is ......... $\%$

Which of the following uses $RNA$ as a template strand for $DNA$ synthesis?