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.
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
FUNCTIO N OF LIPIDS Fats are storage products of both plants and animals. I n plants , fats are commonly stored in spores and seeds while in animals they are sto
What are the Abnormalities of gaze Normal gaze is when visual axes both eyes are parallel in primary gaze. when visual axes are not parallel in primary gaze, it is abnormal ga
what chemistry
Access burs through the crown: Carbide fissure burs : cut through metal ( amalgam alloy or cast metal ) or composite resin. Porcelain fused to metal : -A round diam
Long buccal nerve The long buccal nerve is a branch of the mandibular division of the trigeminal nerve which provides sensory innervation to the buccal gingiva and mucosa of th
Rejection Reaction For rejection reaction the physiological and biochemical processes are set in the pistil by the recognition reaction specific to the type of pollen that lan
Bilateral - Metazoa Bilaterally symmetrical animals have the major axis running from head (anterior) to tail (posterior). They have a ventral (lower) and dorsal (upper) surfac
Nervou s System It is controling system of body. Ectodermal in origin. This system is made up of nervous tissue. Nervous tissue is made up of neuron & neuroglial
Q. How are the three major arthropod classes characterized according to the presence of antennae? Crustaceans have two pairs of antennae insects have one pair arachnids don't h
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