Heartwood differs from sapwood in

Assertion $(A)$: $A$ particle of mass $m$ dropped into a hole made along the diameter of the Earth from one end to the other executes simple harmonic motion.
Reason $(R)$: Gravitational force between any two particles is inversely proportional to the square of the distance between them.

If $\log_{7} 2 = m$,then $\log_{49} 28$ is equal to

The moment of inertia of a uniform thin rod of length $L$ and mass $M$ about an axis passing through a point at a distance of $\frac{L}{3}$ from one of its ends and perpendicular to the rod is:

Leaves that produce microspores and megaspores are called:

The image of the point $(3, 2, 1)$ in the plane $2x - y + 3z = 7$ is