Zigya Logo

Chapter Chosen

Cell Cycle and Cell Division

Book Chosen

Biology

Subject Chosen

Biology

Book Store

Download books and chapters from book store.
Currently only available for.
CBSE Gujarat Board Haryana Board

Previous Year Papers

Download the PDF Question Papers Free for off line practice and view the Solutions online.
Currently only available for.
Class 10 Class 12
Describe significance of mitosis.

Significance of mitosis :

1. It is an equational division. The daughter cells are identical to each other and also to the parent cell in genetic constitution.

2. Mitosis helps in the survival of a species and continuation of its race. It gives a complete set of genetic information to each cell.

3. Mitosis is related to the growth of an individual from zygote to adult stage.

4. It helps in repairing of cells, healing of wounds and regeneration of body cells. 

5. It helps in maintaining a specific nucleocytoplasmic ratio in a cell.

 


Name the process in which there is an exchange of genetic material between non-sister chromatids of homologous chromsomes during meiosis.

Crossing over.

 Namethe five phases of of Prophase I.

The five phases of prophase 1 are
i. Leptotene
ii. Zygotene
iii. Pachytene
iv. Diplotene
v.  Diakinesis. 

Name an important event that occurs during meiosis and not during mitosis.

Crossing over takes place during meiosis but not during mitosis.

 What are two types of cells on the basis of presence or absence of nucleus ?

On the basis of the presence and absence of nucleus the cells are divided into two types Eukaryotic and prokaryotic cells.

What is polyteny ?

Polytene chromosomes are giant chromosomes which are formed due to repeated DNA replication without cell division. They are found in some insects.