AP BIOLOGY

THE MOLECULAR BASIS OF INHERITANCE

DNA REPLICATION

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Which of the following is/are true of nucleosomes?I. They contain six histone proteinsII. They control gene expressionIII. They help in DNA supercoiling
A
I only
B
II only
C
II and III only
D
I, II and III
Explanation: 

Detailed explanation-1: -The nucleosome consists of DNA and proteins. It is present in eukaryotes. In eukaryotes, the organization of DNA is complex and is carried out by a set of positively charged basic proteins called histones.

Detailed explanation-2: -Answer and Explanation: a. DNA is wrapped around proteins known as histones to form structures called nucleosomes. This statement is true.

Detailed explanation-3: -Correct option C It consists of DNA and proteinsExplanation:Nucleosome is the smallest unit of DNA packaging containing 200 nitrogen bases and four types of histone proteins i.e. H2A H2B H3 and H4.

Detailed explanation-4: -The nucleosome is the fundamental subunit of chromatin. Each nucleosome is composed of a little less than two turns of DNA wrapped around a set of eight proteins called histones, which are known as a histone octamer. Each histone octamer is composed of two copies each of the histone proteins H2A, H2B, H3, and H4.

There is 1 question to complete.