Posts

Asexual Reproduction

Asexual Reproduction:- There are no specialised gametes. There is no fertilisation -Cells in one part of the body divide by mitosis to form a structure that breaks away from the parent body and grows into a new organism. Eg Hydra undergoes asexual reproduction by buddying. Asexual Reproduction produces genetically identical offspring. - because all the cells of the new individual are produced by mitosis from just one cell in the body of the adult. -when cells divide by mitosis, they form the exactly same cells are originally and these are called clones. When is asexual reproduction useful? - when the habitat/ environment for an organism is suited/stable, it will reproduce genetically identical offspring who are also going to be suited to this environment.
Post a Comment
Read more

Sexual Reproduction

In sexual reproductions, specialized sex cells called gametes are produced. These carry one set of genetic information of the male/ female. Male mobile  Gamete = sperm Female stationary gamete = ovum (egg) Fertilization = the fusion of the male gamete, the sperm with the female gamete, the ovum to produce a zygote. Zygote = the single cell produced by fertilization The zygote is able to undergo mitosis to form all the cells of the animal. It forms an embryo. Fertilisation :- Once the sperm has reached the ovum, its nucleus must enter the ovum and fuse with the ovum nucleus - As each gamete has only half the normal number of chromosomes, the zygote formed will have a full number. Sperm = 23 chromosomes (haploid number) Ovum = 23 chromosomes (haploid number) Zygote = 46 chromosomes (diploid number)
Post a Comment
Read more

Reproduction

2 types of reproduction - sexual - asexual Reproduction = the production of more organisms of the same species (to produce offspring) (to  have an organism pass on its genes
Post a Comment
Read more