Question

Which of the following statements about euchromatin is TRUE?

a) it replicates earlier during the S phase than heterochromatin
b) it stains lightly by DNA-binding chemicals
c) Both A and B
d) Neither A nor B

Answer 1

The true statements about euchromatin are that it replicates earlier during the S phase than heterochromatin and it stains lightly with DNA-binding chemicals, making the correct answer 'Both A and B'.

Step-by-step explanation:

Euchromatin is the less compact form of DNA, which contains genes that are actively transcribed. In contrast to the tightly packed heterochromatin, euchromatin is characterized by two distinct features relevant to the question posed. First, euchromatin replicates earlier during the S phase than heterochromatin due to its active role in transcription which requires accessibility to DNA replication machinery.

Second, it stains lightly with DNA-binding chemicals because of its less condensed structure, making the DNA more accessible and thus less able to retain the stains that are indicative of dense chromatin regions.Therefore, the correct answer to the student's question is c) Both A and B, as both statements are true for euchromatin.