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

Issues to be addressed by counsellor, Issues to be addressed by counsellor ...

Issues to be addressed by counsellor while counselling a diabetic patient The following issues should also be addressed while counselling a diabetic patient and their family me

Can high blood pressure cause coronary sclerosis, Q. Can High blood pressur...

Q. Can High blood pressure cause coronary sclerosis? High blood pressure causes coronary sclerosis (hardening in early stages, fatty lesions in the inner surface of [he artery

Signify the difference between bryophytes and tracheophytes, Which of the b...

Which of the below determines the major difference between bryophytes (pron: bry-oh-fites) and tracheophytes (pron: tray-key-o-fites)? a) Tracheophytes can make their own food

Phylum ciliophora - protozoan, Phylum Ciliophora - Protozoan Simple ci...

Phylum Ciliophora - Protozoan Simple cilia or compound ciliary organelles typical in at least one stage of life cycle; subpellicular cilia present even if surface cilia are ab

Respiration, how energy enters and then flows through a biological system

how energy enters and then flows through a biological system

What is ventilation, What is ventilation   A.  An increase in the hydro...

What is ventilation   A.  An increase in the hydrogen ion concentration in the interstitial spaces of the  brain stem leads to an increase in the duration of the respiratory cy

How might stem cells be used to treat brain diseases, How might stem cells ...

How might stem cells and other tools of "regenerative medicine" be used to treat brain diseases? Fuelled by the hope which stem cells may have the capacity to rebuild virtually

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