Key Terms
Gametes - Specialised sex cells that usually come in two types, a male (sperm) and female (ovum)
Mitosis - When a cell splits to create two identical copies of the original cell (happens in asexual reproduction)
Meiosis - When a cell divides twice to create four copies of the original cell which are not usually identical (happens in sexual reproduction)
Flagellum - A thin thread like feature of a cell that enables them to swim
Pituitary Gland - A gland in the brain that controls several other hormone glands
Mitosis - When a cell splits to create two identical copies of the original cell (happens in asexual reproduction)
Meiosis - When a cell divides twice to create four copies of the original cell which are not usually identical (happens in sexual reproduction)
Flagellum - A thin thread like feature of a cell that enables them to swim
Pituitary Gland - A gland in the brain that controls several other hormone glands
Asexual Reproduction
Asexual reproduction involves only one individual parent. The parent creates genetically identical offspring who are genetically identical to each other, and their parent. They are known as clones. There are no gametes or fertilisation. The cells divide many times through mitosis. Animals such as the Green Hydra reproduce asexually, but this type of reproduction is more common on plants.
Asexual reproduction is useful in places where the environment is stable. This is because if the parent is stable in its environment, its identical offspring will also be stable in the environment.
Asexual reproduction is useful in places where the environment is stable. This is because if the parent is stable in its environment, its identical offspring will also be stable in the environment.
Sexual Reproduction
Sexual reproduction needs two parents, a male and a female. Each parent produces sex cells, called gametes, the male gamete is called sperm and the female gamete is called an egg. Sexual reproduction involves two gametes from different parents. In fertilisation these sex cells fuse to form a zygote, a genetically unique individual, creating non-identical offspring that inherit characteristics from both of the parents.
The type of cell division that produces gametes is called meiosis.
The type of cell division that produces gametes is called meiosis.
Reproduction in plants happen both sexually and asexually. If it happens sexually, it is a result of dispersion.
The two main methods of Pollination of a plants' seeds are by animal or wind. If it is pollinated by wind, the pollen grains would be light so it can travel through the wind. Examples include dandelion seeds. If the grains are dispersed by animal, it would have bright petals or an attracting scent to bring in the animals. The pollen grains would attach to the animal, which would go to the next plant and leave the grains there as the pollen grains attach to the stigma. Examples are flowering plants such as roses or daisies.
The seeds would travel from the anther of one plant (the male part) to the stigma of another (the female part).
The seeds would travel from the anther of one plant (the male part) to the stigma of another (the female part).
OxNotes Revision Notes Summary for Asexual and sexual reproduction
Coming 5 April 2014.