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
Genetic Diversity of Population The biological diversity of animals, plants, and microorganisms is of fundamental importance to human survival. The term "gene resources" may b

CELL MEMBRANE It is biological, thin, elastic, flexible & selective permeable membrane. Term "Cell membrane" was coined by Negeli & Crammer 1855. Term " Plasma membr

Explain the Digestibility Coefficient? You have earlier learnt that dietary proteins are hydrolyzed to amino acids during digestion. The digestion begins in the stomach by the

How do you draw in organic chemistry format a carbon double bonded to an oxygen atom when this carbon is the first carbon on a carbon skeleton of a molecule?

How is the genetic determination of sex established in humans? In the diploid genome of human beings there are 46 chromosomes, 44 of them are autosomes and two are sex chromoso

Aujeszky's disease This is primarily a disease of pigs, which serve as the principal reservoir host. The secondary hosts include cattle, horse, sheep, goat, dog and cat but hu

Determine the maximum crop yield In determining maximum crop yield it was thought that a given plant let us say corn, is only inherently capable of producing a given amount of

What is the relation among fecundation and the end of the meiotic process during oogenesis? The oocyte II only completes the second meiotic division (interrupted at metaphase) i

Determine the term - Neuropsychological approach The neuropsychological approach relies on the use of tests in which poor performance may indicate either focal (localised) or d

is the study of internal structure of cell included in cell biology or anatomy?