Sexual reproduction, Biology

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.

Posted Date: 12/11/2012 4:06:57 AM | Location : United States







Related Discussions:- Sexual reproduction, Assignment Help, Ask Question on Sexual reproduction, Get Answer, Expert's Help, Sexual reproduction Discussions

Write discussion on Sexual reproduction
Your posts are moderated
Related Questions
Q. What is the name of the terminal portion of the axon? The terminal portion of the axon is called as presynaptic membrane Through, this membrane neurotransmitters are release

Equipment :  Basically, it has an intra aortic balloon pump. A balloon with a capacity of 40 ml is passed percutaneously through the femoral artery up to the upper end of descen

How is a disease-resistant plant selected for successful breeding? Why is the process of fertilisation in a flowering plant referred to as double fertilisation? Explain. Nam

What are the three main parts into which a neuron can be divided? What are their respective functions? The three mains parts into which a neuron can be didactically separated a


Nutrient Cycling in Tropical and Temperate Forests From this study of the nutrient cycles you must have realised the importance of the role of green plants that take up nutri

External features of human heart Human heart is a muscular, hollow organ situated slightly towards left side of the thorasic cavity. It is made up of special muscles call

Define Precautions - Estimation of Nitrogen and Protein Content? 1. The apparatus should be airtight to prevent leakage of NH 3 . 2. The tip of the delivery tube should be i

why we call leech as sangivorous

Explain about the Lactation Process? Lactation is a physiologic process which has profound relevance for both the mother and the newborn. It is the period following pregnancy w