Test: Pollination - NEET MCQ

The plant in the diagram is likely pollinated by wind.

Here's why:

- The plant has feathery structures resembling stigmas, which catch pollen.
- The lack of showy petals or nectar suggests a reliance on wind.
- Wind-pollinated plants typically have lightweight pollen that can be carried by ai
Therefore, based on its characteristics, wind is the most likely pollination method for this plant.

The correct answer is: D: Statement I is correct; Statement II is correct and Statement II explains Statement I.

- Explanation:
- Cleistogamous flowers have an advantage and a disadvantage over chasmogamous flowers.
- Seed set is assured even without pollinators, but genetic variations are less in cleistogamous compared to chasmogamous flowers.
- This means that cleistogamous flowers ensure seed production without external help, but with limited genetic diversity, which is explained by the second statement.

To prevent both autogamy and geitonogamy, the correct choice is C:

Dioecious plant bearing only male or female flowers. Here's why:

- Dioecious plants have separate male and female individuals, reducing the likelihood of self-pollination.
- By having only male or female flowers on each plant, cross-pollination between different plants is necessary for fertilization, preventing both autogamy (self-pollination) and geitonogamy (pollination between different flowers of the same plant).

• 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

Correct Answer: D

- Autogamy refers to the process where a flower is self-pollinated, ensuring fertilization without needing another flower.
- Cleistogamous flowers are self-pollinating flowers that never open, ensuring autogamy.
- Therefore, it is accurate to say that cleistogamous flowers always exhibit autogamy as they are designed to self-pollinate without the need for external agents like insects or wind.

Zostera is mainly called as marine eelgrass and pollinated by water method . This process is known as Hydrophily. Vallisneria is epihydrophily which occurs through the surface of the water.

So, the correct option is B.

• 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

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 of self 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

Wind-pollinated flowers are characterized by traits facilitating pollination by wind.

The exception is D: Many ovules in each ovary. its actually Wind pollinated flowers often have a single ovule in each ovary and numerous flowers packed into an inflorescence; a familiar example is the corn cob – the tassels you see are nothing but the stigma and style which wave in the wind to trap pollen grains.Here's why:

- Wind-pollinated flowers typically have:
- Large, often-feathery stigma to catch airborne pollen effectively.
- Light and non-sticky pollen grains that can be carried by the wind.
- Well-exposed stamens for easy dispersal of pollen.
- Having many ovules in each ovary is not a characteristic related to wind pollination; it's more about seed development after pollination.

The correct answer is D: Pollination by water in Vallisneria.

- Vallisneria is a submerged aquatic plant that relies on water for pollination.
- It has separate male and female flowers on different plants.
- Male flowers detach and float on the water surface, releasing pollen.
- The pollen is then carried by water currents to reach the female flowers for pollination.
- This method ensures successful fertilization in underwater environments.

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

- Both the assertion and reason are true.
- Assertion: Exine of a pollen grain is made of sporopollenin, resistant to extreme conditions.
- Reason: Sporopollenin absence at germ pores is unrelated to its resistance.
- Sporopollenin's durability doesn't depend on its presence at germ pores.
- Choice B: Both statements are accurate, but the reason doesn't directly explain the assertion's resistance properties.