Modification of mitosis, Biology

Assignment Help:

MODIFICATION OF MITOSIS

1.      CRYPTOMITOSIS OR PROMITOSIS :

Primitive type of mitosis. In this mitosis nuclear membrane not disappear (remain intact throughout the division). All the change of karyo kinesis occur inside nucleus even the formation of spindle (intranuclear spindle) centriole is absent. Occur in some protozoa animal during binary fission eg. amoeba.

2.      DINOMITOSIS :

Cell division of dinoflagellate. Dinoflagellate are mesokaryotyes Eukaroytes in which chromatid threads without histone due to absence of histone, chromosome fail to condense properly so chromosome are not distinclly visible during division.

3.      FREE MUDELUR DIVISION :

Karyo kinesis is not followed by cytokinesis. These lead to coenocytic condition. eg. acellular slime mouldes, endosperm.

4.      ENDOMITOSIS :

Division or duplication of chromosome without division of nucleus. Endomitosis lead to polyploidy. Increase no of set chromosome. Colchicine induce polyploidy in plants. It is a mitotic poison. Interferes in normal mitosis retards the arrangement of spindle fibre. Arrest the cell cycle at metaphase.

Besides colchicine Mustard gas and Ribonucleases are also mitotic poison. They inhibit protein synthesis. Stop cell cycle in G phase. Total blockage of mitosis occur.


Related Discussions:- Modification of mitosis

Selenium, S e l e n i u m Selenium toxicity due to pollution of ...

S e l e n i u m Selenium toxicity due to pollution of environment has been reported in animals. Contamination of pasture from industries emitting fly ash particularly fo

Evolutionary changes in humans, Evolutionary changes that occurred in human...

Evolutionary changes that occurred in humans are - Development of prominent chin. Increase in cranial capacity. Reduction of brow-ridges. Development of speech. Developme

Regeneration - root and shoot morphogenesis, Regeneration - Root and Shoot ...

Regeneration - Root and Shoot Morphogenesis Higher plants have three kinds of regenerative activities; All plants possess inherent ability to regenerate lost parts. Fo

Which of the substances is chromatin made, Q. Which Of the substances is ch...

Q. Which Of the substances is chromatin made? Chromatin is made of the DNA molecules associated to proteins known as histones.

Types of cleavage, Types of Cleavage a) Radial Type : If each of the ...

Types of Cleavage a) Radial Type : If each of the blastomeres of upper tier lies exactly over the corresponding blastomeres of the lower tier the pattern of cleavage is radia

What are instances of a carnivorous, Q What are instances of a carnivorous ...

Q What are instances of a carnivorous and an herbivorous reptile? Iguanas are herbivorous, Snakes are carnivorous. Q. Do beings of the class Reptilia perform gas exchange i

Explain hardy weinberg equilibrium., MN blood group in humans is under the ...

MN blood group in humans is under the control of two co-dominant alleles M and N. Blood typing results of a population having of 1349 individuals showed that:  -  363 persons h

How is the skin involved in the regulation of temperature, Q. How is the sk...

Q. How is the skin involved in the regulation of body temperature? Skin is one of various organ systems participating in maintaining a core temperature, meaning the temperature

What is more and less biologically complex, What is more and less biologica...

What is more and less biologically complex out of whey protien and ice cream and why?

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