Question

question 32
a nucleotide is composed of:
a nitrogen base, phospholipids, and a disaccaride
b nitrogen base, phosphate, and a pentose sugar
c nitrogen base, phosphate, and a triose sugar
d nitrogen base, phosphate, and a hexose sugar

Explanation:

A nucleotide is a basic building block of nucleic acids (like DNA and RNA). It consists of three components: a nitrogen - containing base (such as adenine, thymine, cytosine, guanine in DNA and adenine, uracil, cytosine, guanine in RNA), a phosphate group, and a pentose sugar. In DNA, the pentose sugar is deoxyribose (a 5 - carbon sugar, which is a type of pentose), and in RNA, it is ribose (also a 5 - carbon sugar, a pentose).

• Option A: Phospholipids are not part of a nucleotide. Disaccharides are not the sugar component of nucleotides.
• Option C: Triose sugar has 3 carbon atoms. Nucleotides have 5 - carbon (pentose) sugars.
• Option D: Hexose sugar has 6 carbon atoms. Nucleotides have 5 - carbon (pentose) sugars.

Answer:

B. nitrogen base, phosphate, and a pentose sugar