Bi-parental reproduction, Biology

Assignment Help:

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.


Related Discussions:- Bi-parental reproduction

Conducting system of the heart, The fibrous rings of the four valves of the...

The fibrous rings of the four valves of the heart are continuous with each other. They not only form the basis for the attachment of the corresponding valve cusps but also form an

Points, What is the classification of protozoa with examples

What is the classification of protozoa with examples

Green leaves give off oxygen in sunlight, Green leaves give off oxygen in s...

Green leaves give off oxygen in sunlight Place some water weed under a funnel in a beaker of water reverse a test tube full of water over the tube of the funnel. Leave the appa

Influence of associated ions, Influence of Associated Ions The second i...

Influence of Associated Ions The second important factor influencing the plant uptake of a given cation is the effects of the ions held in association with it. For instance, as

Non insulin dependent diabetes mellitus, Q. Explain about Non Insulin Depen...

Q. Explain about Non Insulin Dependent Diabetes Mellitus? Overweight and obese adults are generally afflicted by this type of diabetes. The insulin produced by the pancreas is

Lysosomes, Lysosomes Lysosomes are small vesicles which are bounded ...

Lysosomes Lysosomes are small vesicles which are bounded by a single membrane & contain hydrolytic enzymes in the form of minute crystalline or semi crystalline granules of

Explain about thiol proteases, Explain about thiol proteases Group of  ...

Explain about thiol proteases Group of  thiol proteases, similar in structure to each other, are found in plants. These include  papain from the papaya fruit and  ficain from f

.ecology, Name three sources of biofuel

Name three sources of biofuel

How to identify the monomer or molecular components, Please help with the f...

Please help with the following: For each of the four macromolecules carbs, lipids, proteins and nucleic acids, please identify the monomer or molecular components and name the b

List the stages of process of behaviour change, Q. List the stages of proce...

Q. List the stages of process of behaviour change? Stages of behaviour change process: · Unawareness · Awareness · Acquiring knowledge · Motivation · Trial

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd