Question

Read the following statements and select the Correct option.
(i) Loosely packed and lightly stained region of chromatin are called as heterochrormatin.
(ii) Densely packed and dark stained region of chromatin are called as euchromatin.
(iii) A typical nucleosome contains 200 bp of DNA helix.

• A. Statements (i) and (ii) are true, but statement (iii) is false.
• B. Statements (i) and (ii) are false, but statement (iii) is true.
• C. Statements (ii) and (iii) are true, but statement (i) is false.
• D. All the statements are true.

Answer 1

The correct option is B Statements (i) and (ii) are false, but statement (iii) is true.

A typical nucleosome contains 200 bp of DNA helix. Nucleosomes constitute the repeating unit of a structure in nucleus called chromatin. Chromatin is held over a scaffold of nan-histone chromosomal (or NI-K) proteins. At some places, chromatin is densely packed to form darkly stained heterochromatin. At other places, chromatin is loosely packed. it is called chromatin Chtornatin. It is transcriptionally active chromatin. Whereas heterochromatin is transcriptionally inactive and late, replicating or heteropycnotic.

So, the correct answer is 'A typical nucleosome contains 200 bp of DNA helix. Nucleosomes constitute the repeating unit of a structure in nucleus called chromatin. Chromatin is held over a scaffold of nan-histone chromosomal (or NI-K) proteins. At some places, chromatin is densely packed to form darkly stained heterochromatin. At other places, chromatin is loosely packed. it is called chromatin Chtornatin. It is transcriptionally active chromatin. Whereas heterochromatin is transcriptionally inactive and late, replicating or heteropycnotic'.

So, the correct answer is 'Statements (i) and (ii) are false, but the statement (iii) is true.'