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

Explain procedure for detection of metanil yellow, Explain Procedure for De...

Explain Procedure for Detection of Metanil Yellow? Carry out the exercise following the steps enumerated herewith. 1. Suspend the food sample in water and shake vigorously.

Define the symptoms of dry beriberi, Define the Symptoms of Dry beriberi? ...

Define the Symptoms of Dry beriberi? Early symptoms are similar to those found in wet beriberi. The muscles become progressively wasted and weak and walking becomes difficult.

Amphibians, Ask questionImagine you are studying a group of amphibian speci...

Ask questionImagine you are studying a group of amphibian species that vary in their habitats, some living in dense murky water, and others living in very clear ponds. What kind of

Endosperm Haustoria, Explain the presence of haustoria in nuclear and helob...

Explain the presence of haustoria in nuclear and helobial endosperm

Which are growth tissues of plants, Which are growth tissues of plants? How...

Which are growth tissues of plants? How do they categorize and where can they be found? Growth tissues of the plants are the meristems. The Meristems are the tissues that produ

What are antibodies, Question 1 Write a short note on the following- ...

Question 1 Write a short note on the following- Theory of clonal selection Interferons Super antigens Helper T cells Auto immunity Active Immunization

Explain the oxidative phase of the pentose phosphate pathway, With the help...

With the help of reaction briefly explain the oxidative phase of the pentose phosphate pathway. The oxidative branch of the pathway generates NADPH and pentose-5 phosphate, th

Explain thoracic, Thoracic (non-cardiac) Antibiotic prophylaxis is give...

Thoracic (non-cardiac) Antibiotic prophylaxis is given routinely in thoracic surgery, but sup- porting data are sparse. In one study, a single preoperative dose of cefazolin be

Define primary motor cortex corticospinal interneuron a, Define Primary mot...

Define Primary motor cortex corticospinal interneuron A Primary motor cortex (M1) corticospinal interneuron A that produces action potentials during movements of the big toe of

What is simple transposition in neonates, What is Simple Transposition in N...

What is Simple Transposition in Neonates ? A baby with this malformation needs to be operated without delay. A very cyanosed infant will require palliation by balloon arteries

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