What is fertilisation in plants?
Types of fertilisation in plants?
Stages of fertilisation in plants?
Factors of fertilisation in plants?
Fertilisation in plants refers to the process of union of the male and female gametes to form a zygote, which develops into an embryo and eventually a seed or fruit.
Types of fertilisation in plants:
1. Self-fertilisation: It occurs when the pollen from a flower's anther fertilises the same flower's stigma or another flower on the same plant.
2. Cross-fertilisation: It occurs when the pollen from the anther of one flower fertilises the stigma of another flower on a different plant.
Stages of fertilisation in plants:
1. Pollination: The transfer of pollen grains from the anther to the stigma either through wind, insects, or other external agents.
2. Germination of pollen grain: The pollen grain germinates on the stigma and produces a pollen tube.
3. Pollen tube growth: The pollen tube grows through the style towards the ovary.
4. Double fertilisation: The pollen tube enters the ovule through the micropyle and releases two sperm cells. One sperm cell fuses with the egg cell to form a zygote, while the other sperm cell fuses with the two polar nuclei to form the endosperm nucleus.
5. Embryo development: The zygote develops into an embryo, and the endosperm develops into nutritive tissue for the embryo.
Factors of fertilisation in plants:
1. Pollen viability and germination: The pollen grain must be viable and capable of germination for successful fertilisation.
2. Pollinator availability: Plants that rely on pollinators for fertilisation require the presence of appropriate pollinators.
3. Compatibility between male and female parts: The pollen should be compatible with the stigma for successful fertilisation to occur.
4. Environmental conditions: Optimal temperature, humidity, and lighting conditions can influence the success of fertilisation.
5. Presence of obstacles: Physical barriers, such as the presence of incompatible pollen or blockages in the reproductive structures, can hinder successful fertilisation.
Fertilisation in plants refers to the process of the fusion of male and female gametes (reproductive cells) to form a zygote, which eventually develops into a new plant.
There are two types of fertilisation in plants:
1. Self-fertilisation: In this type, the male and female reproductive organs are present within the same flower, allowing the plant to fertilize itself.
2. Cross-fertilisation: In cross-fertilisation, pollen from one plant is transferred to the female reproductive organ of another plant, resulting in genetic diversity.
The stages of fertilisation in plants are as follows:
1. Pollination: The transfer of pollen grains from the anther (male reproductive organ) to the stigma (female reproductive organ) is known as pollination. It can occur through various methods such as wind, water, insects, or other animals.
2. Germination of pollen: Once the pollen lands on the stigma, it absorbs moisture and germinates, producing a pollen tube.
3. Pollen tube growth: The pollen tube grows from the stigma, through the style, and reaches the ovule (female reproductive structure).
4. Double fertilisation: When the pollen tube reaches the ovule, it releases the male gametes (sperm cells). One sperm cell fuses with the egg cell to form the zygote (2n), which develops into the embryo. The other sperm cell fuses with polar nuclei to form the endosperm (3n), which provides nourishment to the developing embryo.
Factors that influence fertilisation in plants include:
1. Pollinators: The presence of appropriate pollinators such as bees, butterflies, birds, or other animals is vital for cross-pollination.
2. Environmental conditions: Factors like temperature, humidity, and availability of water can affect the viability of pollen grains and the receptivity of the female reproductive organs.
3. Genetic compatibility: The compatibility between the male and female gametes is crucial for successful fertilisation. Some plants have specific mechanisms to prevent self-fertilisation, promoting cross-fertilisation.
4. Timing: The synchrony of pollen release and stigma receptivity is crucial for successful pollination and fertilisation.
These are the basic aspects of fertilisation in plants, along with its types, stages, and factors influencing the process.