CBSE Class 12 Biology — Sexual Reproduction in Flowering Plants

Identify the plant in which emasculation is not required for artificial hybridization.

(a) (i) How does a farmer use dormancy of seed to his advantage? [1] (ii) Differentiate between pea seed and castor seed. [1] OR (b) Identify the stage of follicle where primary oocyte undergoes first meiotic division. Also mention the products of this division. [2]

(a) Do all pollen grains remain viable for the same length of time? Support your answer with two suitable examples. [2½] (b) How are pollen grains stored in pollen banks? [½]

Draw a neat diagram of megasporangium of an angiosperm and label any six parts. [$\frac{1}{2} \times 6 = 3$]