Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
SEXUAL REPRODUCTIONYou 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 aboutvariability. 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.
why phloem made of living cells
Q. What are the three kinds of protein fibers of the connective tissue proper? The matrix of the connective tissue proper is made of elastic fibers, collagen fibers and reticul
Manual and Automatic Toothbrushes Brushing is imperative and soft or medium toothbrushes are recommended. Small heads are useful because they allow better access. Automatic too
Q. Can you briefly explain about parasitism? The Parasitism is an inharmonious interspecific ecological interaction in which individuals of a species (the parasites) explore or
Define Reagents for Measurement of pH? Buffer solutions of pH 4, pH 7 and pH 9.18 for calibration and an unknown solution (i.e. solution of unknown pH) You can prepare these
Potassium, Calcium, Iron and Magnesium - Microorganism? These are supplied by inorganic salts and exist in the cell as cations. These perform various functions in the cell like
What should we focus on During pregnancy? Our focus should be strongly on the preventive aspects of nutrition, identify women at-risk, recognize special needs for counseling, a
Q. What are the major components of the cytoskeleton? The cytoskeleton is a network of very small filaments and tubules distributed throughout the cytoplasm of eukaryotic cells
How to calculate the raw score for each scale The raw score for each scale is the sum of the 0, 1 and 2 item scores. Thus, the higher the score, the poorer the performance. Th
Gastrulation Process - Formation of Primitive Streak Gastrulation in all amniotes involving eutherian mammals is related to a characteristic structure termed as the primitive
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!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd