Which are the most primitive types of organisms?

The distance of the point $(1, 1, 9)$ from the point of intersection of the line $\frac{x-3}{1} = \frac{y-4}{2} = \frac{z-5}{2}$ and the plane $x+y+z=17$ is

The major product obtained in the following reaction is

What is the current through an ideal $PN-$ junction diode shown in the figure below? (in $mA$)

Two concentric hollow spherical shells have radii $r$ and $R$ $(R \gg r)$. $A$ charge $Q$ is distributed on them such that the surface charge densities are equal. The electric potential at the centre is

What is incorrect for $Nostoc$ and $Anabaena$?