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.
Alterations occurring in nuts and oilseeds Some oilseeds have acquired a great significance in the large-scale industrial production of edible oils. You have already studied t
Features of Plant Hormones The following are the important features of the role of plant hormones in growth and development: The hormone may initiate one response
Q. What is the molecular formula of glucose? How can its structural formula be explained? The molecular formula of glucose is C 6 H 12 O 6 . Structurally glucose is a hexago
A Molecule of DNA is 2.17 um long. The ends of the molecule become strongly ionixed: negative on one end, positive on the other. The helical molecule acts like a spring and compres
SPINAL NERVES 31 Pairs. Mixed type. Total weight 150 gms. At the base of origin of spinal nerves gland of swammardon or calcarious ganglion is present. Composed of m
Define the Toxicity of Vitamin K? Vitamin K, does not produce any toxic effects in doses (10-20 mg) normally used for the treatment or subjects suffering from disorders of liv
cephalization
COMMON DISEASE OF CATTLE & BUFFALOES - 1 . Anthrax - Its symptoms are high temp, painless & warmthless swellings on different body parts. Bloody discharge from na
Spiracular Control - Respiration Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
Define Precautions for Preparation of Phosphate Buffers? 1. Glass electrodes should always be dried before and after measuring pH with a tissue paper. 2. The pipettes should
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