Reproduction

The correct answer is A. Reproduction produces new offspring, allowing a species to continue across generations. It does not perform an individual’s functions such as digestion, blood transport, or waste removal.

Asexual reproduction occurs from a single parent and does not involve the fusion of male and female gametes. Therefore, one parent is needed.

In sexual reproduction, male and female gametes usually fuse to form a zygote, the first cell of the new organism.

Amoeba commonly reproduces by binary fission: its cell divides into two daughter cells, each of which can grow into an individual.

In budding, a small outgrowth forms on the yeast cell, grows and develops into a new cell. Since it forms from one parent without gamete fusion, it is asexual reproduction.

In Hydra, a small bud grows as an outgrowth on the parent and can eventually separate to live as a new individual. This method is called budding.

Spirogyra is a filamentous alga. In fragmentation, its filament breaks into pieces, and each suitable fragment can grow into a new individual.

Rhizopus forms spores in sporangia. Under suitable conditions, the spores can germinate and grow into new organisms, so Rhizopus is an example of spore formation.

Vegetative propagation is the formation of a new plant from a vegetative part of the parent, such as a root, stem or leaf, rather than from a seed.

A potato tuber is a modified stem. Its eyes contain buds, which can sprout and grow into new plants under suitable conditions.

Bryophyllum can form buds along the margins of its leaves. These buds can develop into new plants, making this an example of vegetative propagation.

Tissue culture grows new plants from small pieces of plant tissue under suitable laboratory conditions. This allows many plants to be produced quickly.

The stamen is the male reproductive organ of a flower. Its anther produces pollen grains.

The pistil is the female reproductive organ. It includes the stigma, style and ovary; ovules are found inside the ovary.

Pollen grains are produced in the anther, which is part of the stamen. They carry the male reproductive cells of the plant.

Ovules are found inside the ovary, which is part of the pistil. After fertilisation, an ovule usually develops into a seed.

Pollination is the transfer of pollen grains from an anther to a stigma. It happens before fertilisation and enables the male reproductive cells to reach the ovule.

In self-pollination, pollen is transferred to the stigma of the same flower or another flower on the same plant. The transfer remains within one plant.

Cross-pollination transfers pollen to a flower on a different plant of the same species. Because the pollen reaches another plant, this differs from self-pollination.

Fertilisation is the fusion of male and female gametes. In flowering plants, this fusion forms a zygote, which can develop into an embryo.

After fertilisation, the ovule usually develops into a seed, and the ovary usually develops into a fruit. The seed contains the developing embryo.

The ovary usually develops into the fruit after fertilisation; the ovules inside it usually develop into seeds.

A seed contains an embryo. When conditions are suitable, it can germinate and grow into a new plant.

Most seeds need water to begin germinating, oxygen from the air for respiration, and a suitable temperature for growth.

The male reproductive cell, or male gamete, in humans is the sperm. It can fuse with an egg during fertilisation.