Question

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Answer 1

Answer:

1. Chromosomes are composed of highly condensed chromatin.
2. A chromosome contains highly condensed DNA.
3. The complex of DNA and proteins present in chromosomes is called chromatin.
4. DNA wraps around special proteins called histones.

Explanation:

1.

Chromosomes are highly condensed form of genetic material composed of DNA and proteins. In a normal, resting cell, chromosomes are present in the form of chromatin. They are only visible during cell division when the DNA is supercoiled. Prokaryotic organisms only possess a single chromosome, whereas, the number varies in multicellular organisms. Humans have 46 chromosomes arranged in two sets of 23 each. Each parent contributes one set to its offspring. This means that two copies of each chromosome are present in an individual. The two copies are called sister chromatids and are joined together by cohesin proteins at a point called the centromere.

2.

Each chromosome contains DNA and a specific number of genes in their corresponding loci (location of a gene on chromosome). A chromosome is the highly condensed form of chromatin. It contains DNA wrapped around special proteins called histones.

3.

Chromation is the decondensed form of chromosomes that contains a complex of DNA and histone proteins. Chromatin is visible in a normal, non-dividing cell.

4.

During the S-phase of cell division, DNA that exists in the form of chromatin condenses into chromosomes. This takes place when DNA double helix wraps around proteins called histones. This forms a bead shaped DNA-histone complex known as the nucleosome. DNA wraps twice around each histone that aids in producing a super-coiling and condensing the chromatin. Histones also give chromosomes their characteristic structure.