Cleavage - metazoa, Biology

Assignment Help:

Cleavage - Metazoa

The unicellular zygote begins cell division (cleavage). First, the single cell divides forming two cells, these redivide further to form four, then eight cells and so on till it gets converted into a ball of cell. The cells are called blastomeres. The planes of the first and second cleavage are vertical passing through the axis, but at right angles to one another. These two cleavages together result in four blastomeres lying side by side around the axis.

The plane of the third cleavage is at right angles to the first two planes and to the axis and is horizontal and hence parallel to the equator of the zygote. This results in eight blastomeres. Of the eight blastomeres four lie on top of the other four. The pattern of cleavage and arrangement of blastomeres around an imaginary central axis in a zygote can be one of two types radial or spiral.


Related Discussions:- Cleavage - metazoa

Explain the nutrient deficiency disorders, Explain the Nutrient Deficiency ...

Explain the Nutrient Deficiency Disorders? Protein Energy Malnutrition (PEM), iron deficiency anaemia (IDA) and vitamin A deficiency (VAD) are still the major public health pro

Complete feed system in ruminants, Complete feed system in ruminants C...

Complete feed system in ruminants Complete feed system for feeding dairy animals is a departure from conventional individual rationing method. It involves the self-feeding of

How many asymmetric the amino acid serine have, How many asymmetric carbons...

How many asymmetric carbons does the amino acid serine have? Please explain with a strucutral diagram if possible.

Myocardial ischemia, In patients with coronary artery disease an acute coro...

In patients with coronary artery disease an acute coronary syndrome event can precipitate heart failure. Mitral regurgitation occurring as a result of papillary muscle ischemia con

How is the nervous system characterized, Q. How is the nervous system chara...

Q. How is the nervous system characterized in beings of the phylum Annelida? How can one compare cephalization in annelids to cephalization in platyhelminthes and nematodes? An

Which foods are used by microorganisms for energy, Q. Which Foods are used ...

Q. Which Foods are used by Microorganisms for Energy? The carbohydrates, especially the sugars, are most commonly used as an energy source, but other carbon compounds can also

Tonicity and the plant cells., Potato type: Potato A: Beginning displaceme...

Potato type: Potato A: Beginning displacement (ml)= Ending displacement (ml) = Potato B: Beginning displacement (ml)= Ending displacement (ml) = Potato type: Potato A: Beginn

Define seminal plasma in human male, Seminal plasma in human males is rich ...

Seminal plasma in human males is rich in : 1. fructose and calcium 2. glucose and calcium 3. DNA and testosterone 4. ribose and potassium Fructose and Calcium

What is cerumen, Q. What is cerumen? Cerumen is a fatty, oily substance...

Q. What is cerumen? Cerumen is a fatty, oily substance produced by theceruminous glands in outer part of ear canal. This compound is generally referred to as ear wax and, toget

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd