Pollination can be categorized into three types based on the source of pollen: autogamy (pollination within the same flower), geitonogamy (pollination between flowers of the same plant), and xenogamy (pollination between flowers of different plants).

NCERT Reference:  Topic “Types of Pollination ”of chapter "Sexual Reproduction in Flowering Plants "of NCERT

• Wind pollination is common in grasses .
• Grasses produce a large amount of pollen which by the help of wind reach to the stigma for reproduction.

Hence, the correct option is C
NCERT Reference:  Topic “Agents of Pollination ”of chapter Sexual Reproduction in Flowering Plants of NCERT

• In self-pollinating plants, there is less dependence on external factors to cause pollination.
• These plants depend on wind or other smaller insects that visit the flower regularly.
• In self- pollinating flowers, the anthers, and stigma are of similar lengths to facilitate the transfer of pollen.

Self -pollination can be further divided into two types:

1. Autogamy –In this type of self-pollination, the pollen is transferred from the anthers of one flower to the stigma of the same flower.
2. Geitonogamy –In this type of self- pollination, the anthers are transferred from the anthers of one flower to the stigma of another flower but on the same plant.

Self Pollination:

Hence, the correct option is A

NCERT Reference:  Topic “Pollination ”of chapter "Sexual Reproduction in Flowering Plants "of NCERT

• Most pollen walls are composed of two major distinct layers:
  (i)  the exine, accumulated primarily by sporopollenin.
  (ii) the intine, mainly composed of pectin and cellulose.
• In addition, different protein and lipid-rich materials form a pollen coat (tryphine) anchor on the exine.

Fig : Layers of Pollen Grain  (Exine &Intine)

Hence, the correct option is B

NCERT Reference:  Topic “Stamen, Microsporangium and Pollen Grain ”of chapter  "Sexual Reproduction in Flowering Plants " of NCERT

• Autogamy is a form of self-pollination that occurs within a single flower. This process requires the stigma (the part of the flower that receives the pollen) to be receptive at the same time the anthers (the part of the flower that produces pollen) release their pollen.
• The synchrony between the release of pollen and the receptivity of the stigma is crucial for the success of autogamy. If the stigma is not receptive when the pollen is released, or vice versa, self-pollination cannot occur.

Autogamy is relatively rare in normal flowers. This is because most flowering plants have evolved mechanisms to prevent self-pollination, favoring cross-pollination instead. These mechanisms help to ensure genetic diversity, which is beneficial for the overall health and survival of the plant species.

NCERT Reference:  Topic “Pollination ”of chapter "Sexual Reproduction in Flowering Plants "of NCERT

• Cleistogamy is autogamous pollination.
• Cleistogamous flowers are those that stay close together to avoid cross pollination and have adaptations to assist self pollination.
• Self-pollination Or  Autogamy:
  
  Fig : Cleistogamous Flowers (inside unopened buds)
• Geitonogamy is the transfer of pollen grains from the anther to the stigma of another flower of the same plant.
•  Xenogamy is the transfer of pollen grains from anther to the stigma of a different plant.
• Chasmogamous flowers which are similar to flowers of other species with exposed anthers and stigma. It helps in both self and cross pollination of flowers.

Hence, the correct option is A

NCERT Reference:  Topic “Pollination ”of chapter  "Sexual Reproduction in Flowering Plants "of NCERT

Emasculation is the process of removing the anthers from the flower bud to prevent self-pollination. It is necessary in artificial hybridization to ensure that only the desired pollen is used for pollination and to avoid contamination with unwanted pollen.

NCERT Reference:  Topic “Outbreeding devices ”of chapter "Sexual Reproduction in Flowering Plants "of NCERT

The filiform apparatus, present at the micropylar part of the synergids, guides the entry of the pollen tube into the ovule. It plays a crucial role in ensuring that the pollen tube reaches the female gametophyte within the ovule for fertilization to occur.

NCERT Reference:  Topic “Pollination ”of chapter "Sexual Reproduction in Flowering Plants "of NCERT

1. Geitonogamy is a type ofself pollination in which pollen is transferred from the anther of one flower to the stigma of another flower of the same plant.
2. Xenogamy is the cross-pollination between the flowers of different plants. It produces hererozygosity because two genetically different parents are involved.
   Cross-pollination is the transfer of pollen grains from anther to stigma of different flower
3. Chasmogamy is the condition in which bisexual flowers have exposed anthers and stigma. Both self-pollination and cross pollination can occur in these flowers.
4. Autogamy is a type of self-pollination in which pollen is transferred from the anther to the stigma of the same flower.

Thus, it 's xenogamy that can bring genetically different pollen grains to the stigma of a plant.

Hence, the correct option is B
NCERT Reference:  Topic “Pollination ”of chapter "Sexual Reproduction in Flowering Plants "of NCERT

In plants exhibiting self-incompatibility, self-pollen is typically rejected when it comes in contact with the stigma. This rejection prevents self-fertilization and ensures that the plant undergoes cross-pollination, which can lead to greater genetic diversity in the offspring. Self-incompatibility mechanisms help maintain genetic variation within plant populations.

NCERT Reference:  Topic “Pollination ”of chapter "Sexual Reproduction in Flowering Plants "of NCERT