Correct option is D
The correct answer is (d).
Histone modifications are required for mitotic chromosome condensation in addition to their role in gene regulation during interphase. Modifications such as phosphorylation, acetylation, and methylation of histones play an essential role in both the condensation of chromosomes during mitosis and the regulation of gene expression. The statement that histone modifications are mainly required for gene repression in interphase is incorrect, as these modifications are also crucial for mitosis and other cellular processes.
Incorrect options-
Option (a) is correct: Condensin I is a key player in forming chromatin loops during mitosis.
Option (b) is correct: Histone H1 is necessary for higher-order packaging in mammalian chromatin.
Option (c) is partially incorrect in its mechanism of interaction but not the main focus here; histones interact mostly by electrostatic forces rather than hydrogen bonding with the DNA backbone.
