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.
Q. Function of Dopamine in consciousness? An increase in dopamine activity produces an increase in wakefulness. Dopaminergic neurons in the ventral tegmental areas are constant
If a lipid bilayer does not form in a test tube of phospholipids in a liquid solvent and instead the heads join together in a circular pattern, the most likely explanation is: a
Female Gametophyte The development of a female gametophyte is initiated with the enlargement of one of the megaspores (usually the one close to the chalaza in a linear tetrad)
Genetic engineering has been successfully used for producing: 1. Transgenic mice for testing safety of polio vaccine before use in humans 2. transgenic models for studying ne
Q. What are the three major cell types that form the osseous tissue? What are their functions? The three major cell types of the osseous tissue are the osteocytes, the osteobla
what are the etiological agents of malaria
Injury Resulting From an Accident Accident was described earlier which meant that accident was a sudden event. However, several legal opinions favored exclusion of suddenness
Explain the role of cuvier in animal taxonomy? Cuvier (1769-1832) was critical of Lamarck's evolutionary concept which thereafter remained in oblivion for half a century. Cuvi
CRANIAL NERVES 12 pairs. Total weight 12 gms. Upto amphibian 10 pairs cranial nerves are present. 1, 2, 8, - sensory. 3, 4, 6, 11, 12, motor. 5, 7, 9, 10 - mixed. 3
What is Atraumatic needles Atraumatic needles with sutures comprise an eyeless needle attached to a specific length of suture thread. There are several shapes of surgical n
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