Question

Anthesis means
A) Growth of pollen tube inside the carpel.
B) Dehiscence of anthers
C) Opening of floral bud
D) Emergence of anthers

Answer 1

Anthesis means the flowering period of a plant from the opening of the flower bud. It is a period during which the flower of the plant is fully open and functional. It may also refer to the onset period in which the flower is ready for pollination. Pollination refers to the act of transferring pollen grains from the male flower to the female flower. Flowers which are diurnal anthesis generally are brightly colored. In order to attract insects like- moths and butterflies.

Complete answer:
A) Growth of pollen tube inside the carpel- Pollination refers to the act of transferring pollen grains from the male flower to the female flower. There are different types of pollination like-self-pollination and cross pollination and these categories are the main ones, others maybe sub-categories. So, let us get a better understanding of pollination in flowering plants.
So, option a is not correct.
B) Dehiscence of anthers- anthers are the male organ in a flower and they need to be transported in order for pollination to occur. When pollen from the male part that is anther in the plant falls directly to the female part that is stigma of the same flower and fertilization occurs. Such pollination is termed as self-pollination. Dehiscence of anthers means- falling of anthers to stigma so that pollination can take place.
So. Option B is incorrect.
C) opening of floral bud- opening of flower or floral bud is termed as anthesis. Anthesis is the phenomena of opening of floral for a specific period of time. Every plant species has their own anthesis or onset period where the flower is ready for pollination and insects act as pollinating agents to play the major role.
So, option C is the correct answer.
D) emergence of anthers- anthers are nothing but the male organ. Pollen from the male part that is anther in the plant falls directly to the female part that is stigma of the same flower and fertilization occurs. This is the whole process we discussed.
So, option D is incorrect.

So, option C is the correct answer.

Note:
Anthesis, as we discussed, is the period of expansion of flowers. The flower expands and remains open during day time or night time. Depending on the viability of organs. The diurnal flowers attract daytime insects to suck nectar and pollination to take place while the nocturnal flowers are opened during night time so that insects like moth species come to feed nectar. They are generally, white or less bright in color.