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.
Classification of Multicellular Animals - Coelom We know earlier that the pseudocoel gave animals specific selective benefits. Among other things, this fluid-tilled space wor
Q. What is signifying when it is said that beings of the phylum Annelida are vascular beings? From which other phyla of the animal kingdom does this feature differentiate them?
Which of the following is TRUE about the properties of aqueous solutions? Select one: a. A pH change from 5.0 to 6.0 reflects an increase in the hydroxide ion concentration (
What is Self-jamming Unless all of the mobile client are perfectly synchronized, the arriving transmissions from multiple clients will not be perfectly aligned on chip boundari
Define Historical example of Ecosystems Science? Mathematical and statistical tools are central to enhancing our understanding of large-scale systems and contain, for instance,
what is somogyi
Describe the Intensity of S 2 in second heart ? Loud A 2 occurs in patients with hypertension, when aorta is closer to anterior chest wall owing to root dilatation or TGA or
what is the modes of reproduction
Name the state in humans in which the blood cholesterol content becomes abnormally high. a) Explain vernalisation. b) Many villagers near Industrial area vary from "blue bab
Describe how the International Astronomical Union defines a planet. Also include why Pluto is no longer considered a planet.
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