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

Frequency - synthetic characters, Frequency - Synthetic Characters Thi...

Frequency - Synthetic Characters This term refers to the degree of dispersion of individual species in an area, and is usually expressed in terms of percentage. Frequency can

+illustrate sturdy evolutionary hypothesis, Q. Why is it a sturdy evolution...

Q. Why is it a sturdy evolutionary hypothesis that although viruses are the structurally simplest beings they were not the first living beings? The fact that viruses are obliga

Lab safety, Why should you not apply cosmetics while doing a lab experiment...

Why should you not apply cosmetics while doing a lab experiment in class?

Agro industrial-by-products from sugar industry, By-Products from Sugar Ind...

By-Products from Sugar Industry India is one of the important sugarcane (Saccharum officinarum) growing countries of the world. Five main by-products are available from the su

How does plasma membrane regulate, How does a plasma membrane regulate move...

How does a plasma membrane regulate movement of molecules into and out of a cell?

Explain etiology, Etiology Fevers can be caused due to 1. Internal (...

Etiology Fevers can be caused due to 1. Internal (endogenous) factors:  This could be caused within the body. Examples are antigen-antibody reactions, malignant cancer, graf

Explain about fats and oils, Explain about Fats and oils Fats and oils ...

Explain about Fats and oils Fats and oils are a unique class of agricultural products in that a high degree of interchangeability among them is possible for many products and u

Define natural gums - hydrocolloids, Natural Gums These are derived fro...

Natural Gums These are derived from various plant as well as microbial sources and are divided into the following four basic categories: 1.  Seaweed gums:   Agar, Alginate,

Plant tissues responsible for the supporting of the plant, Which are plant ...

Which are plant tissues responsible for the supporting of the plant? The plant supporting tissues are the sclerenchyma and the collenchyma. The collenchyma is made of elonga

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