Identify the odd one out.

Calculate the $pOH$ of a solution at $25\,^{\circ}C$ that contains $1 \times 10^{-10} \, M$ of hydronium ions,i.e.,$H_3O^{+}$.

Which of the following mixtures is known as fusion mixture?

$A$ telescope has an objective lens of focal length $150 \ cm$ and an eyepiece of focal length $5 \ cm$. If a $50 \ m$ tall tower at a distance of $1 \ km$ is observed through this telescope in normal setting,the angle formed by the image of the tower is $\theta$ (in degrees),then $\theta$ is close to..... (in $^{\circ}$)

In $Pteridophytes$,meiosis occurs during which of the following processes?

What are the selected organs,tissues,or cells from a plant called in plant tissue culture?