Which of the following hormones does not naturally occur in plants?

When electromagnetic radiation of wavelength $300 \ nm$ falls on the surface of a metal,electrons are emitted with the kinetic energy of $1.68 \times 10^5 \ J \ mol^{-1}$. What is the minimum energy needed to remove an electron from the metal? $(h = 6.626 \times 10^{-34} \ J \ s, c = 3 \times 10^8 \ m \ s^{-1}, N_A = 6.022 \times 10^{23} \ mol^{-1})$

The pole of the straight line $x+4y=4$ with respect to the ellipse $x^2+4y^2=4$ is

Which of the following compound$(s)$ has '$Z$' configuration?

$A$ $20 \, cm$ length of a certain solution causes right-handed rotation of $38^\circ$. $A$ $30 \, cm$ length of another solution causes left-handed rotation of $24^\circ$. The optical rotation caused by a $30 \, cm$ length of a mixture of the above solutions in the volume ratio $1 : 2$ is:

Male gametes are flagellated in