Which of the following is used extensively in biochemical and genetic work?

Select the incorrect statement.

Assertion $(A)$: In bread mold $(Rhizopus)$,sexual reproduction does not result in the formation of an embryo.
Reason $(R)$: In sponges $(Porifera)$,the cell wall is made of cellulose.

After karyogamy followed by meiosis,spores are produced exogenously in

The fungus $Claviceps$ $\text{purpurea}$ (ergot) infects which of the following plants?

$A$ multinucleated cell is called .......