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!
Events after Sperm and Egg Fusion
The entry of the sperm into the egg activates the egg. The activation of egg results in two types of responses.
(1) The early responses and
(2) The late responses.
The early response for the entry of the sperm into the egg is the prevention of polyspermy i.e. the entry of or fusion of more than one sperm into the egg. Polyspermy may result in several abnormalities such as polyploidy, abnormal mechanism of chromosomal separation during cell division and ultimate death of the embryo. Organisms have evolved different types of mechanisms for prevention of entry of more than one sperm into egg. Generally any one of the three different strategies may be involved in the prevention of polyspermy. For instance in fishes the sperm can enter into the egg only through the narrow opening the micropyle, the rest of the egg being covered by the impermeable chorion. In sea urchins and mammals there is a restriction on the number of sperm that are able to penetrate the extracellular coats and fuse with the egg. In mammals the sperm have to migrate the long female reproductive tract to reach the egg and further, the structural changes in zona pellucida block polyspermy. Certain animals such as salamanders do permit the entry several sperm into the egg but only the nucleus of one of the sperm can fuse with the egg to form the zygote nucleus; other sperm nuclei degenerate.
what are characteristics of flagellata class ?
What is the radula? What is the function of this organ? Some molluscs have a tongue-like structure with harsh saliences similar to small teeth. This structure is called radula
Malpighian Tubules Other arthropods like insects and myriapods and arachnids have Malpighian tubules, the outgrowths of alimentary canal like excretory organs. Malpighian tub
what is osmoregulation.
Define the Dietary Guidelines? Dietary Guidelines are becoming increasingly powerful tools to help the general public to appreciate the role of diet in prevention of degenerati
Q. Explain Nutritive and Non-Nutritive Sweeteners? Nutritive Sweeteners: We know some sweeteners like glucose, honey, molasses, fruit juice, dextrose, maltose, mannitol, sorbit
Is there a difference between the initial and the final energy levels in catalyzed and non-catalyzed reactions? The catalysis does not alter the energetic state of reagents and
Based on your reading of the article "The Inner Life of the Genome" which of the following is a wrong statement regarding the organization of chromosomes within the nucleus? A.
OVARIES - 2 in number (didelphic). White / pinkish. Almond like. 3 cm long, 2 cm wide, 1 cm thick. Lie in the lower part of abdomen attached to dorsal wall by mesovarium.
Explain anterior pituitary gland secretes hormones The anterior pituitary gland secretes hormones that elevate the blood glucose and therefore antagonize the action of glucose
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