Question

Read the following statements and select the correct option.
(i) Lightly stained regions of chromatin are called heterochromatin.
(ii) Dark stained region of chromatin is called euchromatin.
(iii) In prokaryotes, DNA is organised in large loops in the nucleoid region, by positively charged proteins.

• 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 statements are true

Answer 1

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

Some parts of DNA are loosely packed and stains lightly. That region of chromatin is called euchromatin. This region is transcriptionally active.
Whereas some parts of the chromatin are packed densely and darkly stained, those regions are called heterochromatin. They are transcriptionally inactive.

In prokaryotes, the DNA is present in cytoplasm in a region called nucleoid where it is held together with the help of some positively charged proteins forming large loops. The DNA in prokaryotes too is negatively charged due to the presence of phosphate groups in its nucleotides.

Hence, statements (i) and (ii) are false, but statement (iii) is true.