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!
Primary Egg Envelopes
These are the egg envelopes which develop in the ovary between oocyte and follicle cells in the space occupied by the interdigitating microvilli. Such envelopes have been named variously in different animals.
a) It is named as vitelline envelope or vitelline membrane in insects, molluscs, amphibians and birds.
b) In tunicates and fishes, it is known as chorion. In many sharks and bony fishes the primary envelope has striated appearance and is referred to as zona radiata representing the degraded microvilli of the growing oocyte. The perforation in the zona radiata becomes the micropyle through which the spermatozoa can enter the egg.
c) In mammals, the unstriated and modified zona pellucida is formed as a result of joint efforts of egg and follicle cells. While escaping the Graafian follicle mammalian oocyte carries on the surface of zona pellucida a layer of follicle cells known as corona radiata. The primary envelopes usually stick closely to the egg surface. These later on participate in the formation of fertilization membrane.
History of Ecology The roots of ecology lie in Natural History, which is as old as human civilisation itself. As a matter of fact man indulged in ecology in a practical sort of
Define the intracellular cyclic AMP Healthy Person P takes a drug that makes a strong effect on the epithelial cells of the kidney collecting duct within one hour and lasts fo
It involves the standardization of copper sulphate solution. This is same as done in the previous activity. 1) Pipette accurately 5 ml of Solution A and Solution B in conical f
Explain the Effect of Deficiency of Vitamin E? Fortunately, vitamin E deficiency in human is extremely rare. This may probably be due to its wide occurrence. in natural foods a
Euthenics : It is the study of improvement of human races by providing better conditions. Euthenics means human improvement by altering external factors like as education or the co
Pheromones Serving Functions Other than Reproduction Besides sexual responses as described above pheromones mediate several other types of behaviour. Alarm pheromones have bee
What are the three main signs of diabetes? The three main signs of diabetes mellitus are called as the diabetic triad: polyuria, polydipsia and polyphagia. Polyuria is the e
Define Dietary Management during Surgery? Surgery increases the nutritional demands of the body and can lead to the elicitation of several nutritional deficiencies/imbalance. M
Explain the Meaning of Transfer of Culture Transfer of culture can be done from one liquid media to another liquid media or from liquid to solid media or vice versa. The steps
Toxoplasmosis Toxoplasmosis, one of the important parasitic zoonoses, occurs all over the world, and is caused by a protozoan parasite Toxoplasma gondii. Its definitive hosts are
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: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd