Introduction to Sexual Reproduction in Humans

2122 Words Feb 18th, 2011 9 Pages
Introduction to sexual reproduction in humans
Reproduction is the process by which humans gives rise to new individuals. Sexual reproduction is the process that involves the fusion of two gametes, sperm (male gamete) and egg (female gamete). In human these gametes are produced in different sexes, the male and female.
Reproduction in humans is performed by reproductive systems, the male and female reproductive systems. The main organs of male reproductive system are testis and gonads and of female reproductive system are vagina, ovaries, and uterus. Main events in sexual reproduction of humans are production of sperms and egg, copulation, and fertilization.
(Sexual Reproduction in Humans) : Production of Gametes
Sperms are produced in
…show more content…
E.g. Hydra, corals, jellyfishes and many echinoderms.
Fragmentation:
Spirogyra is a filamentous freshwater green algae having chloroplasts in spirally twisted bands.
An alga breaks up into two or more fragments. These fragments or pieces grow into new individuals. This process continues and they cover a large area in a short period of time. Fragmentation is caused by mitosis. Meiosis is not involved in fragmentation.
Fragmentation can be seen in many organisms such as molds, some annelid worms, and sea stars.
Sporogenesis or Spore Formation:
Spore formation is the process of reproduction via spores. The fungi on a bread piece grow from spores which are present in the air. When spores are released they keep floating in the air. As they are very light they can cover long distances.
The spores are asexual reproductive bodies. Each spore is covered by a hard protective coat to withstand unfavorable conditions such as high temperature and low humidity. So they can survive for a long time. Under favorable conditions, a spore germinates and develops into a new individual.
Reproductive spores are formed in many eukaryotic organisms, algae and fungi, during their normal reproductive life cycle. Plants such as moss and ferns also reproduce by means of spores.
Parthenogenesis:
Parthenogenesis ("virgin birth") is a form of asexual reproduction found in females, where growth and development of embryos occurs