(1)Nucleotides are building blocks of nucleic acids. Each nucleotide i...
Nucleotide→ base + sugar + phosphate......
Nucleoside→ base +sugar....
So, option A is correct.....
(1)Nucleotides are building blocks of nucleic acids. Each nucleotide i...
Introduction
Nucleotides are the building blocks of nucleic acids, which include DNA and RNA. These molecules play a crucial role in storing and transmitting genetic information. Each nucleotide is a composite molecule consisting of three components: a nitrogenous base, a sugar molecule, and a phosphate group.
Explanation
The correct answer is (a) base - sugar - phosphate. Let's break down the components of a nucleotide to understand why this is the correct answer:
1. Base
The base is the nitrogenous component of a nucleotide. There are four types of bases found in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G). In RNA, uracil (U) replaces thymine. The base provides the genetic information and forms specific base pairs with complementary bases in the double helix structure of DNA.
2. Sugar
The sugar component in a nucleotide is either deoxyribose in DNA or ribose in RNA. These sugars are pentose sugars, meaning they have five carbon atoms. The sugar molecule forms the backbone of the nucleic acid chain and connects the bases together.
3. Phosphate
The phosphate group is a negatively charged molecule that consists of one phosphorus atom bonded to four oxygen atoms. It attaches to the sugar molecule through a phosphodiester bond. The phosphate group provides stability to the nucleotide and allows for the formation of the DNA or RNA backbone.
Composition of a Nucleotide
Therefore, the correct composition of a nucleotide is as follows:
- Base: Adenine (A), Thymine (T), Cytosine (C), Guanine (G), or Uracil (U) in RNA.
- Sugar: Deoxyribose in DNA or Ribose in RNA.
- Phosphate: A negatively charged phosphate group bonded to the sugar molecule.
Conclusion
In summary, nucleotides are composite molecules consisting of a nitrogenous base, a sugar molecule, and a phosphate group. The correct answer is (a) base - sugar - phosphate. Understanding the composition of nucleotides is essential for comprehending the structure and function of nucleic acids.
To make sure you are not studying endlessly, EduRev has designed NEET study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in NEET.