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.
What do you mean by Syconoid sponge. Of different sponge architectures, this is intermediate in its complexity. Spongocoel is no longer lined with choanocytes, now located in r
Q. Explain microbiology of Soil? Ans. You would realize that the soil contains greatest varieties of microorganisms. It actually serves as a medium for growth and developm
Q. What are the three major types of RNA? What is meant by heterogeneous RNA? Messenger RNA, or mRNA, transfer RNA, or tRNA, and ribosomal RNA, or rRNA, are the three main type
What event marks the beginning of the menstrual cycle? What is the blood concentration of FSH, LH, estrogen and progesterone in this phase of the cycle? By convention the menst
How is light from the sun transformed into chemical energy to be used by the living beings on earth? Light from the sun is transmitted into chemical energy contained in organic
Describe the factors that are involved in the regulation of respiration in a child who decides to hold his/her breath for as long as possible.
Palaeobiology : This deals with the study of fossils and remains an impressions of the past organisms found in the rock of different ages. Paleobiology is a growing or comparativel
Define the meaning of Vital signs Vital signs are measures of different physiological statistics, often taken by health professionals, in order to assess the most basic body f
Q. How can the hypothesis that asserts that chloroplasts as well as mitochondria were primitive prokaryotes that related in mutualism with primitive anaerobic eukaryotic cells be c
Discuss the example of Comprehensive neuropsychology Example of these include deficits of visuo-spatial perception hampering performance on construction tasks, poor comprehe
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