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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
Chromosomes get aligned at the centre of the cell during:
A. Metaphase
B. Anaphase
C. Prophase
D. Telophase
Name the sex chromosomes in human males and females
Differentiate between
Gametic meiosis and Zygotic meiosis.
Name the following:
Microtubules form the bipolar spindle in which stage.
Multiple Choice Question:
After mitotic cell division, a female human cell will have
Write the functional activity of the following structure:
Spindle fibers
Name the following:
Pair of genes responsible for a particular characteristic.
Some of the chromosomes have an elongated knob-like appendages known as telomere.
The two non-sister chromatids of a paired chromosome are attached to each other at ______ during the process of crossing over.
Distinguish between the following pair:
Karyotype and Karyokinesis
