Products of cleavage - morula and blastula, Biology

Assignment Help:

Products of Cleavage (Morula and blastula)

In several cases, the blastomeres in early cleaving stages tend to presume spherical shape like that of the egg earlier than cleavage. Even though their mutual pressure (resulting from limited available space in the egg envelopes) flattens the surface of blastomeres in contact with each other, the free surfaces of each blastomere stay spherical. The result of it is that after some cleavage divisions have taken place the embryo has a shape that resembles mulberry. Due to this superficial resemblance this stage of embryonic development of many animals has been considered to as Morula (Latin for mulberry).

As cleavage divisions carry on the subsequent arrangement of the blastomeres in the morula may change in different groups of animals. In some the blastomeres are packed together with no any space among them, or a small cavity appears but is soon obliterated. In both cases the result is the creation of a solid blastula called stereoblastula example some flatworms, annelids, molluscs and coelenterates. In such type of blastulae some of the blastomeres lie externally and others in the interior. But, in several animals the cavity appearing among the blastomeres persists and may enlarge. This cavity is termed as blastocoel. As the cleavage progresses, the adhesion of the blastomeres to one other increases and they arrange themselves as an epithelial layer around the blastocoel. This stage of embryonic development is termed as blastula and such blastula is called coeloblastula (hollow blastula). The layer of blastomeres is considered to as blastoderm.


Related Discussions:- Products of cleavage - morula and blastula

State the continuous sutures suturing technique, State the Continuous sutur...

State the Continuous sutures Suturing technique It can be used to attach 2 surgical flap edges or to secure multiple interproximal papillae of one flap independently of the oth

Microorganisms, discuss the importance of protozoa to humans

discuss the importance of protozoa to humans

State the female reproductive system, State the Female Reproductive System ...

State the Female Reproductive System The female reproductive organ consists of the following: Uterus receives fertilied ovum and featus develops in it Two ovaries produce

Kreb cycle, where does kreb cycle takes place

where does kreb cycle takes place

Explain the crystal twinning, What is Crystal twinning Crystal twinning...

What is Crystal twinning Crystal twinning happens when two separate crystals share some of the similar crystal lattice points in a symmetrical manner. The result is an intergro

Proteins requirement in dyslipidemia, Q. Proteins requirement in dyslipidem...

Q. Proteins requirement in dyslipidemia? Proteins: While the quantity of protein does not impose any significant impact on the serum lipoproteins, it is the quality of protein,

Forebrain - olfactory lobes, Forebrain 1 .       OLFACTORY LOBES - ...

Forebrain 1 .       OLFACTORY LOBES - 1 pair, very small, solid, club shaped, separated from each other. Fully covered by cerebral hemispheres on dorsal side, clear on

What is the other name given to the sex chromosomes, Q What is the other na...

Q What is the other name given to the sex chromosomes? What is the function of the sex chromosomes? Sex chromosomes are also known as allosomes the other chromosomes that are n

Stratification of vegetation - qualitative characters, Stratification of Ve...

Stratification of Vegetation - Qualitative Characters Stratification of vegetation is another important feature of plant communities. There are different vertical strata in di

What volume of 4x protein sample buffer, What volume of 4x protein sample b...

What volume of 4x protein sample buffer do you need to add to 15 ml of a cell extract in order to load it on a gel?

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