How do pistils function in sexual reproduction in plants?

Pistils, the female reproductive part of a flower, function in sexual reproduction by producing ovules and facilitating fertilisation.

The pistil is the innermost part of a flower and is typically located in the centre. It is composed of three main parts: the stigma, the style, and the ovary. Each of these parts plays a crucial role in the process of sexual reproduction in plants.

The stigma is the topmost part of the pistil and is often sticky or feathery in nature. This is where the process of sexual reproduction begins, as it is designed to capture and trap pollen grains that are carried by the wind or transported by insects. Once the pollen grains land on the stigma, they germinate and produce a pollen tube that grows down through the style to reach the ovary.

The style is the elongated, tube-like structure that connects the stigma to the ovary. It acts as a pathway for the pollen tube, allowing the male gametes (sperm cells) contained within the pollen grain to travel down to the ovary. The style also provides a protective barrier against potential pathogens that could harm the ovary.

The ovary is the base part of the pistil and contains one or more ovules. Each ovule houses a female gamete (egg cell). When the pollen tube reaches the ovary, it releases the sperm cells, which then fertilise the egg cell within the ovule. This fertilisation process results in the formation of a zygote, which eventually develops into a seed. The ovary itself matures into a fruit, which protects the developing seeds and aids in their dispersal.

In summary, the pistil plays a vital role in plant sexual reproduction by facilitating the process of fertilisation and the subsequent development of seeds and fruit.