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.
How calcium prevents luxury consumption of potassium Increasing Ca:K ratio in soil solution depresses the uptake of potassium. Thus one of the harmful effects of over liming m
Q. Can you explain Protease inhibitors? Ans. Protease inhibitors are the compounds which are found to some extent in cereal grains such as oats, wheat, barley and mai
How does the structure of a chloroplast enable it to build up a concentration gradient of protons? Chloroplasts have an inner membrane system having of thylakoids. The pumpin
Explain the Behavioural Observations of the child Behavioural observations of the child are the second critical source of information available to the neuropsychologist. Qualit
Define Stripping Perforation - Types of Root Perforation It is latral perforation caused by over instrumentation through a thin wall of the root. Most common on the in
If I take a drug that induced the synthesis of CYP 2E1 in my system, would that raise or lower my blood alcohol level after I drink a beer or wine (compared to if I hadn''t taken t
Q. Show the principle parts of a mold? The principle parts of a mold are a web-like structure known as mycelium and the spore. The mycelium is often white and cottony and penet
a precaution to follow when heat fixing a smear
Q. How does the contraceptive diaphragm work? What are the limitations of this contraceptive method? The contraceptive diaphragm is an artifact made of plastic or latex that wh
Define drawbacks of Nutritional status that assessed traditionally? Nutritional status assessed traditionally with the use of anthropometric, biochemical clinical and dietary a
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