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प्रश्न
Explain the structure of chromosomes with labelled diagram.
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उत्तर
Structure of chromosome:
- A typical chromosome consists of two chromatids joined together at the centromere also known as primary constriction.
- Primary constriction consists of a disk shape plate called the kinetochore. During cell division, spindle fibers get attached to the kinetochore.
- Apart from primary constriction, a few chromosomes possess an additional one or two constrictions called secondary constriction.
- At secondary constriction I (nucleolar organizer), nucleolus becomes organized during interphase.
- A satellite body (SAT body) is attached at secondary constriction II, in very few chromosomes.
- Each chromatid in turn contains a long, unbranched, slender, highly coiled double-stranded DNA thread, called chromonema, extending through the length of the chromatid.
- The ends of chromosomes (i.e. chromatids) are known as telomeres.
A: Parts of chromosomes
B: Showing secondary constrictions and details
Structure of Chromosome
संबंधित प्रश्न
Mention whether the following statement is (T) Or (F). Give reason in support of your answer.
The unfertilized human egg has half the number of chromosomes of the body cells.
Mention the contribution of the scientist given below in the study of chromosome:
Waldeyer
The number of chromosomes in a certain type of cell division is halved. This kind of cell division occurs in ______.
Write the functional activity of the following structure:
Chromosome
Complete the following sentence with appropriate word:
The chromosomal theory of inheritance was proposed by ____________in 1902.
Write the functional activity of the following structure:
Chromosomes
Compare X chromosome and Y chromosome.
The centromere is found at the centre of the ______ chromosome.
An inheritable change in the amount or the structure of a gene or a chromosome is called ______.
