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

State the definition of soil, State the definition of soil The definiti...

State the definition of soil The definition of soil has changed a great deal from a thin "outer layer of  Earth's crust" to "a collection of natural bodies on the surface of th

Exchange transfusion, Exchange transfusion An exchange transfusion is ...

Exchange transfusion An exchange transfusion is the serial withdrawal and injection of small amounts of blood through a central vein-usually umbilical until the required volu

Role of glucose-6-phosphate dehydrogenase - gene expression, Define Role of...

Define Role of Glucose-6-phosphate dehydrogenase - Gene Expression? Glucose-6-phosphate dehydrogenase (G6PD) is another enzyme involved in lipogenesis that is regulated by diet

Which the dna is made based on the rna template, Q. Is there any situation ...

Q. Is there any situation in which the DNA is made based on the RNA template? What is the enzyme involved? The process in which the DNA is synthesized having as template a RNA

How successful are you at synthesizing genes, How successful are you at syn...

How successful are you at synthesizing genes with really high G/C content? A: We have an extremely low failure rate, which is about one out of five thousand or ten thousand gen

Retention of soil moisture, Retention of Soil Moisture The movement of ...

Retention of Soil Moisture The movement of water into and within the soil, moisture storing capacity of soils and the availability of moisture to plants are governed by soil pr

Define needs of fluid in postoperative nutritional care, Define Requirement...

Define Requirements of Fluid in Postoperative Nutritional Care Extensive fluid losses may occur through vomiting, haemorrhage, diesis, excudate, fever and sweating after a surg

What are the alleles of a gene, What are the alleles of a gene? The Dip...

What are the alleles of a gene? The Diploid individuals have paired chromosomes. For instance in humans there are 23 pairs of chromosomes totaling 46 chromosomes. Every pair co

Spina bifida occulta, Spina Bifida Occulta There is no protrusion of ...

Spina Bifida Occulta There is no protrusion of the meninges but the vertebrae are bifid. There are three components of the spina bifida occulta. a) Vertebral- there is

Which are the brain regions associated with memory, Which are the brain reg...

Which are the brain regions associated with memory? According to researchers some of the main regions of the nervous system associated with the memory phenomenon are the hippoc

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