Question

Emasculation is not required, when flowers are
a. Bisexual
b. Intersexual
c. Unisexual
d. None of the above

Answer 1

Hint: Emasculation is the process, where the stamens or anthers are removed, and pollen grains are not allowed to enter into the female reproductive parts to prevent fertilization, the main aim of emasculation is to prevent the self-pollination of flowers.

Complete answer:
Emasculation is done by various methods, the main things are male reproductive parts are damaged or removed.
This process is most commonly done in the bisexual flowers in order to prevent the pollination in between those.

Various methods of Emasculation.
> Hand emasculation: It is usually done in the species of large flowers, where the anthers are removed by hand with the help of forceps, this process can be done before the anther dehiscence, first the corolla should be opened and later anthers are removed, in some cases, the corolla is also removed and the anthers are removed with forceps.

> Suction method: This method is commonly done in small flowers, but it should be done immediately once the flowers are opened. Here the glass tube or something is attached to the suction and the anthers and pollen is used, care should be taken to not prevent the gynoecium, anyway even though we have done the emasculation 10℅ of pollination occurs.

> Hot water method: In general name, reproductive organs are more sensitive to hot water than the female, so the flowers are dipped in hot water, before the other dehiscence.

> Coldwater method: This method has the ability to kill the pollen grains, it is not more effective than the hot water method.

> Genetic method: In this method, the cytoplasm is made sterile in order to do the emasculation.

> Alcohol method: It is not commonly used, So it is mainly required in bisexual plants to prevent the self-pollination, not useful in unisexual flowers.

Hence, The correct answer is option (C).

Note: Apart from the all above methods mentioned for emasculation, there is another method, where the artificial chemicals are used to kill the male gametes without affecting the female, for example, sodium methyl arsenate, zinc methyl arsenate.