Solveeit Logo

Question

Biology Question on Structure of DNA and RNA

Read the following statements and select the correct option. (i) Loosely packed and lightly stained region of chromatin are called as heterochromatin. (ii) Densely packed and dark stained region of chromatin are called as euchromatin. (iii) A typical nudeosome contains 200200 bp of DNADNA helix

A

Statements (i) and (ii) are true, but statement (iii) is false

B

Statements (i) and (ii) are false, but statement (iii) true

C

Statements (ii) and (iii) are true, but statement (iv) false

D

All the statements are true

Answer

Statements (i) and (ii) are false, but statement (iii) true

Explanation

Solution

A typical nudeosome contains 200bp200 \,bp of DNADNA helix. Nudeosomes constitute the repeating unit of a structure in nucleus called chromatin. Chromatin is held over a scaffold of non-histone chromosomal (or NHCNHC) proteins. At some places chromatin is densely packed to form darkly stainined heterochromatin. At other places chromatin is loosely packed. It is called euchromatin. It is transcriptionally active chromatin whereas heterochromatin is transcriptionally inactive and late replicating or heteropycnotic.