Why reproduce? Asexual reproduction

Reproduction is the function that makes new individuals of the same kind. For one single individual it is less vital than the other functions: an organism that never breeds can live out its life, and the removal of the reproductive organs from some organisms did not stop their normal life, but if feeding, breathing or another basic function stops, the individual soon dies. So reproduction depends on the other functions and not the reverse. Its importance is for the species: it keeps the species going after individuals die, and if it fails in a whole population, the species becomes extinct. The number of offspring a kind of organism produces is its reproductive capacity. It differs with the surroundings, the hardships, the way of life, the life span and the size. Aquatic organisms produce many more offspring than their relatives on land. Parasites produce many more than free-living organisms, to make up for their losses. Simple or short-lived organisms produce more than higher or long-lived ones, whose young are better cared for and protected. Living things reproduce in two main ways, asexual and sexual. In asexual reproduction a part of the body, such as a spore, a group of cells or a tissue, is separated and grows into a new organism that fully resembles the one it came from. One parent is enough, and it rests on mitosis, so every new cell receives a complete 2N set of chromosomes. The offspring stay the same even if the surroundings change, so if the parents were not adapted to the change, most of the offspring are lost. This way is common in plants and limited to some primitive animals. Sexual reproduction is the topic of Week 7.