Read the following and select the set of correct statements.
(A) Euchromatin is transcriptionally inactive
(B) Heterochromatin is more densely packed
(C) Heterochromatin is loosely packed
(D) Euchromatin is transcriptionally active
(E) Euchromatin stains lighter
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (B), (D) and (E) Only
(A) Euchromatin is transcriptionally inactive — False. Euchromatin is transcriptionally active.
(B) Heterochromatin is more densely packed — True.
(C) Heterochromatin is loosely packed — False. It is densely packed.
(D) Euchromatin is transcriptionally active — True.
(E) Euchromatin stains lighter — True.
NCERT Extract:
Packaging of DNA Helix – “… The beads-on-string structure in chromatin is packaged to form chromatin fibers that are further coiled and condensed at metaphase stage of cell division to form chromosomes. The packaging of chromatin at higher level requires additional set of proteins that collectively are referred to as Non-histone Chromosomal (NHC) proteins. In a typical nucleus, some region of chromatin are loosely packed (and stains light) and are referred to as euchromatin. The chromatin that is more densely packed and stains dark are called as Heterochromatin. Euchromatin is said to be transcriptionally active chromatin, whereas heterochromatin is inactive.”