Double fertilization is a characteristic feature of which of the following?

The period of $\sin ^4 x + \cos ^4 x$ is

Which one of the following is not a second messenger in hormone action?

If the line $3x - 2y + 6 = 0$ meets the $X$-axis and $Y$-axis at points $A$ and $B$ respectively,then the equation of the circle with radius $AB$ and center at $A$ is:

If the extremities of a diagonal of a square are $(1, -2, 3)$ and $(2, -3, 5)$,then the length of its side is

The length of the latus rectum of the parabola $y^2+8x-2y+17=0$ is