Which family do pulse-producing plants belong to?

The focal length of a mirror is given by $\frac{2}{f} = \frac{1}{v} - \frac{1}{u}$. In finding the values of $u$ and $v$,the errors are equal to $p$. Then,the relative error in $f$ is

If the terminal speed of a sphere of gold (density $= 19.5 \times 10^3 \, kg/m^3$) is $0.2 \, m/s$ in a viscous liquid (density $= 1.5 \times 10^3 \, kg/m^3$),find the terminal speed of a sphere of silver (density $= 10.5 \times 10^3 \, kg/m^3$) of the same size in the same liquid.

The cathode of a photoelectric cell is changed such that the work function changes from $W_1$ to $W_2$ $(W_2 > W_1)$. If the current before and after the change are $I_1$ and $I_2$,respectively,and all other conditions remain unchanged,then (assuming $hv > W_2$):

Match the organism with its use in biotechnology.

$(a)$ Bacillus thuringiensis	$(i)$ Cloning vector
$(b)$ Thermus aquaticus	$(ii)$ Construction of first $rDNA$ molecule
$(c)$ Agrobacterium tumefaciens	$(iii)$ $DNA$ polymerase
$(d)$ Salmonella typhimurium	$(iv)$ Cry proteins

Select the correct option from the following:

Progesterone is secreted by .........