The inheritance and transmission of characters
Reproduction and inheritance
- Asexual reproduction: The new living being reproduces from a single organism. The descendants are genetically identical to their parent, they are natural clones. The bacteria or sponges reproduce asexually. Others, like plants, can reproduce sexually, through seeds, for example, and asexually, as when a new plant is generated from a piece of potato.
- Sexual reproduction: Each of the two parents provides specialized cells for reproduction (gametes), which after their union (fertilization), originate a new individual with genetic information from both parents. Children are different from parents and their siblings.
Gametes are formed by meiosis from diploid cells. They are haploid (n) cells, with half the chromosomes. Thus, when fertilization occurs, it will give rise to a new diploid cell (egg or cogote cell) from which the new individual will emerge.
Remember that male and female gametes are different:
- Male gamete: the sperm (in animals) and anterozoid (in plants) is smaller than the female and mobile, because it has to travel a path to find the female gamete.
- Female gamete: the ovule (in animals) and oosphere (in plants) is immobile and much larger than the male, since it contains the necessary nutrients for the first phases of the new individual.