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

Western Ghats have a large number of plant and animal species that are not found anywhere else. Which of the following terms is used to denote such species?

Let $\overline{a}=2 \hat{i}+\hat{j}-2 \hat{k}$ and $\overline{b}=\hat{i}+\hat{j}$. Let $\overline{c}$ be a vector such that $|\overline{c}-\overline{a}|=3$,$|(\overline{a} \times \overline{b}) \times \overline{c}|=3$,and the angle between $\overline{c}$ and $\overline{a} \times \overline{b}$ is $30^{\circ}$. Then $\overline{a} \cdot \overline{c}$ is equal to

If the amplitude of $z-2-3i$ is $\frac{\pi}{4}$,then the locus of $z=x+iy$ is:

Two opposite and equal charges $4 \times 10^{-8} \, C$ are placed $2 \times 10^{-2} \, cm$ apart,forming a dipole. If this dipole is placed in an external electric field of $4 \times 10^8 \, N/C$,what are the values of the maximum torque and the work done in rotating it through $180^o$?

At $20^{\circ}C$,the concentration of $Ag^{+}$ ions in a saturated solution of $Ag_2CrO_4$ is $1.5 \times 10^{-4} \ mol/L$. The solubility product $(K_{sp})$ of $Ag_2CrO_4$ at $20^{\circ}C$ is: