Bi-parental reproduction, Biology

Bi-Parental Reproduction

In sexually reproducing metazoans, there are separate and distinct male and female individuals. Each has its own reproductive system and produces one kid of sex cell, spermatozoon or egg. Nearly all vertebrates and many invertebrates have separate sexes, and such a condition is celled dioecious and this type of reproduction is called biparental reproduction. However, some animals such as most flatworms, some hydroids, annelids, crustaceans and some fishes have both male and female organs in the same individual. Such a condition is called hermaphroditism. In contrast to the dioecious state of separate sexes, hermaphrodites are monoecious, having both male and female organs in the same organism Most of the hermaphrodites avoid self-fertilization by exchanging germ cells with each other.

For example, although the earthworm bears both male and female organs, its eggs are fertilised by the copulating male and vice versa. Hermaphrodites also prevent self-fertilisation by developing eggs and sperms at different times. If we admit that all living things are mortal, that every living organism is endowed with a life span that must eventually end, then reproduction is indispensable for the continuance of species. During evolution the efficiency of reproduction increased where the parents protect and provide nutrition for the young before or after birth. The adaptations that are found in vertebrates are internal fertilisation, the cleidoic (enclosed in shell) egg, and the foetal membranes. Parallel adaptations are also found in lower animals.

Posted Date: 1/16/2013 6:47:10 AM | Location : United States







Related Discussions:- Bi-parental reproduction, Assignment Help, Ask Question on Bi-parental reproduction, Get Answer, Expert's Help, Bi-parental reproduction Discussions

Write discussion on Bi-parental reproduction
Your posts are moderated
Related Questions
Q. List the steps of mitosis and briefly describe what happens in each.

How does the structure of a chloroplast enable it to build up a concentration gradient of protons?  Chloroplasts have an inner membrane system having of thylakoids. The pumpin

Describe about Acyanotic Congenital Heart Disease ? The following lesions will be discussed here: Left to right shunts: Atrial Septal Defect (ASD), Ventricular Septal Defect

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Japanese encephalitis The Japanese encephalitis is a mosquito-born flavivirus infection that causes encephalitis in human and equines and abortion in pigs, caused by Japanese

How plants use the pattern of changes in day/night length to solve the paradox that day length is equal twice a year. Plants possess the ability to balance the daily changes in

Explain what is DNA? DNA : DNA is the source of the information that directs the development of the cell. Although all segments of DNA are not active in every cell in the huma

Q. What are some factors that can lead to protein denaturation? Protein denaturation can be caused by temperature variation, pH change, changes in the concentration of surround

Explain the Prevalence of iron deficiency anaemia? We can find out about the prevalence of anaemia if we know what percentage of population is suffering from anaemia. The WHO h

Provide a link to the graph, describe the variables, and interpret the meaning of the graph