Sexual reproduction, Biology

Assignment Help:

SEXUAL REPRODUCTION

You must be aware that reproduction is one of the distinguishing features of living beings. Reproduction is basically of two types: asexual and sexual. In asexual reproduction an organism propagates itself without the formation of sex cells or gametes. Sexual reproduction is more complex than the asexual type. It is based on the production of two kinds of gametes, the male and the female. The gametes are microscopic and in order that they fuse, certain specific conditions are required. This makes sexual reproduction so very specialised.

You may question why a complex and difficult mode of reproduction is found in nature when a simpler mode is available. It is because, an offspring that has been produced asexually has exactly the same genetic constitution Like that of its parents. Asexual reproduction necessarily involves mitosis which is a conservative process maintaining the status quo ante of the genetic material. On the other hand, sexual reproduction causes genetic variability in offspring. This is due to meiosis which is an essential component of sexual reproduction. Meiosis generates enormous variation through dependent assortment ofh omologous chromosomes and crossing-over. In addition, randam fusion of gametes at the time of fertilisation also contributes in generating variation.

You may recall that genetic.variability is a precondition for biological evolution. A species that is unable to evolve would sooner or later become extinct. Sexual reproduction hence is seen in a majority of existing forms of life to bring about
variability. To ensure a sexual mode of reproduction, most organisms have evolved different 'mating types' or 'sexes'.

In nature there is a vast array of diverse mechanisms of sex determination in different species.


Related Discussions:- Sexual reproduction

What is meant by post-translational modification, What is meant by "post-tr...

What is meant by "post-translational modification"? Give examples of post-translational modifications of the following amino acids: a. Serine b. Lysine C. Choose a third amino acid

Genetic repatterning during isolation, An island may be colonised by just a...

An island may be colonised by just a few individuals, or just a pair:, or even a single gravid female. When a new population develops from these early colonisers of the island, the

What is guided bone regeneration, What is Guided bone regeneration Gui...

What is Guided bone regeneration Guided bone regeneration (GBR) allow the practitioner to place implants in patients who would not have received this treatment option a few y

Explain about probiotics and prebzotics, Explain about Probiotics and Prebz...

Explain about Probiotics and Prebzotics? We all have read or heard about probiotics and prebiotics at some point of time. However, what exactly do we mean by these terms? When

Define recommended intake of fibre, Define Recommended Intake of Fibre? ...

Define Recommended Intake of Fibre? 1. A minimum of fibre intake of 20 g/day is recommended by the American Dietetic Association (ADA), the National Cancer Institute, US and th

Express the term - amnion, Express the term - Amnion One of the extraem...

Express the term - Amnion One of the extraembryonic membranes found in terrestrial vertebrate. The amnion is filled with fluid and the developing embryo of reptiles, birds, and

Regulatory factors, 1. Describe how the hypothalamus regulates the secretio...

1. Describe how the hypothalamus regulates the secretion of anterior pituitary hormones and identify all of the individual hypothalamic regulatory factors. Describe how the hypotha

Describe examination of chest and abdominal, Describe Examination of chest ...

Describe Examination of chest and abdominal ? As already mentioned earlier, any overt deformity of the chest, for example kyphosis, scoliosis, pectus exacavatum and pectus car

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