Which of the following is common between Pteridophytes and Bryophytes?

$\int_{-\pi / 2}^{\pi / 2} \sin |x| \, dx$ is equal to

If $(1, a)$ and $(b, 2)$ are conjugate points with respect to the circle $x^2+y^2=25$,then $4a+2b$ is equal to

When radiation of wavelength $\lambda$ is incident on a metallic surface,the stopping potential is $4.8 \ V$. If the same surface is irradiated with radiation of wavelength $2\lambda$,the stopping potential is $1.6 \ V$. The threshold wavelength for the metal is:

The human hindbrain comprises three parts,one of which is:

$A$ weak acid $HX$ has the dissociation constant $1 \times 10^{-5} \ M$. It forms a salt $NaX$ on reaction with alkali. The percentage hydrolysis of $0.1 \ M$ solution of $NaX$ is ........ $\%$.