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.
Equivalence point and end point - Nutritional Biochemistry? Titrimetric analysis volumetrically measures the amount of reagent, often called a titrant, required to complete a
Explain diet from Lifestyle Risk Factors ? The lifestyle factors are the way of living of an individual and comprise of the diet, smoking, alcohol, physical activity and stress
Fishe s - Heart is 2 chambered 1 auricle & 1 ventricle present. Sinus venosus, truncus or conus arteriusus present. Only impure blood come in heart so heart is venous he
What are deciduous trees? Deciduous trees are plants that lose their leaves in a period of the year. In the case of the deciduous trees of the temperate forest the fall of the
How do birds reproduce? Birds, like each vertebrate, have sexual reproduction. Their embryos develop within shelled eggs having extraembryonic membranes and outside the mother'
Define Requirements and Recommended Dietary Allowances (RDA)? What do we mean by requirements and RDA? The requirement level is the amount of nutrient needed to be absorbed to
What is an analogy for a smooth endoplasmic reticulum? Endoplasmic reticulum (ER) is such as a manufacturing plant, like a factory, where proteins and lipids are made. This is
A hypothesis can be used to predict the outcome of future testing. Which type of hypothesis is easier to test? A. It is easier to specify and test for a difference between two outc
The organisms that live in hostile environments that cannot support other forms of life are members of what kingdom?
Q. Various types of microorganisms? Microbes are single-cell organisms so tiny that millions can fit into the eye of a needle. They are the oldest form of life on earth. Micro
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