Advertisements
Advertisements
प्रश्न
How does colchicine act as mitotic poison? Is there any advantage of it?
उत्तर
Colchicine is an alkaloid obtained from Autumn crocus (Colchicum autumnale). It inhibits the formation of mitotic spindle. As a result, chromosomes duplicate but they remain within the same cell, increasing in number (endoduplication). Such cells are called polyploid cells.
Its advantage is that plant breeders have used colchicine-induced polyploidy as a means of producing variants of agricultural and horticultural crops.
APPEARS IN
संबंधित प्रश्न
The term “chromosomes” literally means ______.
Correct the following statement if there is any mistake:
If there are 46 chromosomes in a cell, there will be 23 chromatin fibres inside the nucleus during interphase.
Answer the following question in your own words.
What is meant by ‘chromosome’?
Mention the contribution of the scientist given below in the study of chromosome:
Waldeyer
Give Reasons for the following
The meiosis is called reductional division
Differentiate between
Gametic meiosis and Zygotic meiosis.
Give Technical Terms
The phase of meiosis at which homologous chromosomes are separated.
Complete the following sentence with appropriate word :
Polytene chromosomes are found in _________ of fly larvae.
Duplicated chromosomes are joined at a point termed ______.
Name the following:
The diploid number for cell of man.
Give Technical Term:
Transmission of characters through generations.
Identify the odd one:-
Define euploidy.
Match the following.
| 1. Autosomes | - | Trisomy 21 |
| 2. Diploid condition | - | 9 : 3 : 3 : 1 |
| 3. Allosome | - | 22 pair of chromosome |
| 4. Down’s syndrome | - | 2n |
| 5. Dihybrid ratio | - | 23rd pair of chromosome |
Read the following statements and select the correct option.
Statement I: The densely packed transcriptionally active, light staining region of chromatin is known as 'Heterochromatin'.
Statement II: The loosely packed, dark staining transcriptionally inactive region of chromatin is known as 'Euchromatin'.
Small swellings on the surface of the chromosome are called______.
Given below is a set of four term. Choose the odd one and write the category of the remaining term:
