Which classification system was proposed by $R.H. Whittaker$?

An inclined plane makes an angle of $30^{\circ}$ with the horizontal. $A$ solid sphere rolling down this inclined plane from rest without slipping has a linear acceleration equal to:

If $\alpha$ and $\beta$ are the roots of the equation $ax^2+bx+c=0$ and the equation having roots $\frac{1-\alpha}{\alpha}$ and $\frac{1-\beta}{\beta}$ is $px^2+qx+r=0$,then $r=$

In a Young's double-slit experiment,the fringe width is $0.2 \, mm$. If the wavelength of light used is increased by $10\%$ and the separation between the slits is also increased by $10\%$,the fringe width will be.......$mm$.

Which of the following organelles is $NOT$ a part of the endomembrane system?

Which of the following animals possesses a four-chambered heart?