Which hormone causes stunted growth in pea?

Which of the following is a $\pi$-complex?

Select the correct statement from the following.

In the Young's double slit experiment using a monochromatic light of wavelength $\lambda$,the path difference (in terms of an integer $n$) corresponding to any point having half the peak intensity is :-

The volume-temperature graphs of a given mass of an ideal gas at constant pressures are shown below. What is the correct order of pressures?

Which of the following is considered an acellular organism?