#nucleic acids

ZOOLOGY

Which of the following elements is a major component of nucleic acids but is not found in carbohydrates?

Nitrogen is a key component of nucleic acids (DNA & RNA) but is absent in carbohydrates. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.

Ref: NCERT Biology Textbook for Class XI and XII (Zoology section), Chapter: Principles of Inheritance, Molecular Basis of Inheritance and Biotechnology, Topic: Genetics, DNA techniques and applications.

View Details

ZOOLOGY

Which of the following statements about nucleic acids is correct?

DNA contains deoxyribose sugar, while RNA contains ribose. DNA is double-stranded, and RNA has uracil instead of thymine. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.

Ref: NCERT Biology Textbook for Class XI and XII (Zoology section), Chapter: Principles of Inheritance, Molecular Basis of Inheritance and Biotechnology, Topic: Genetics, DNA techniques and applications.

View Details

ZOOLOGY

Which of the following statements about nucleic acids is correct?

RNA is usually single-stranded, while DNA is double-stranded and contains deoxyribose sugar. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.

Ref: NCERT Biology Textbook for Class XI and XII (Zoology section), Chapter: Principles of Inheritance, Molecular Basis of Inheritance and Biotechnology, Topic: Genetics, DNA techniques and applications.

View Details

ZOOLOGY

Which of the following statements about nucleic acids is correct?

RNA is usually single-stranded, while DNA contains deoxyribose and thymine instead of uracil. This follows from NCERT principle where relation explains outcome clearly for students.

Ref: NCERT Biology Textbook for Class XI and XII (Zoology section), Chapter: Molecular Basis of Inheritance, Topic: Nitrogenous bases, uracil in RNA, thymine in DNA.

View Details

BOTANY

Which of the following organisms lacks both DNA and RNA?

Prions are infectious proteins that lack both DNA and RNA, unlike viruses and viroids. This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.

Ref: NCERT Biology Textbook - Latest Edition for Academic Session 2026-27 (Botany section, Rationalized Textbook for Class XI and XII), Chapter: Biology - Botany portion (Latest NCERT Textbooks for Academic Session 2026-27 -

View Details

Nucleic Acids - Structure - Nucleotides, Sugars and Base Pairing

Which component of a nucleotide provides the backbone structure?

The sugar and phosphate groups form the backbone of nucleic acids via phosphodiester bonds.

Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Nucleic Acids - Structure - Nucleotides, Sugars and Base Pairing

View Details

Nucleic Acids - Structure - Nucleotides, Sugars and Base Pairing

Which base pairs with adenine in DNA?

In DNA, adenine pairs with thymine via two hydrogen bonds, following base-pairing rules.

Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Nucleic Acids - Structure - Nucleotides, Sugars and Base Pairing

View Details

Nucleic Acids - Structure - Nucleotides, Sugars and Base Pairing

Which nucleic acid contains a sugar with a missing hydroxyl group at C2?

DNA contains deoxyribose, which lacks an -OH group at C2, unlike ribose in RNA.

Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Nucleic Acids - Structure - Nucleotides, Sugars and Base Pairing

View Details

Nucleic Acids - Structure - Nucleotides, Sugars and Base Pairing

Which type of bond links the sugar and nitrogenous base in a nucleotide?

A glycosidic bond connects the sugar (ribose or deoxyribose) to the nitrogenous base in a nucleotide.

Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Nucleic Acids - Structure - Nucleotides, Sugars and Base Pairing

View Details

Nucleic Acids - Structure - Nucleotides, Sugars and Base Pairing

Which nucleic acid base forms a triple hydrogen bond with its complement?

Guanine pairs with cytosine in DNA via three hydrogen bonds, enhancing stability.

Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Nucleic Acids - Structure - Nucleotides, Sugars and Base Pairing

View Details

Nucleic Acids - Structure - Nucleotides, Sugars and Base Pairing

Which base is found in RNA but not in DNA?

Uracil is present in RNA, replacing thymine, which is exclusive to DNA.

Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Nucleic Acids - Structure - Nucleotides, Sugars and Base Pairing

View Details

Nucleic Acids - Structure - Nucleotides, Sugars and Base Pairing

Which of the following is a component of nucleic acids?

Nucleic acids (DNA and RNA) are composed of nucleotides, each containing a nitrogenous base like adenine.

Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Nucleic Acids - Structure - Nucleotides, Sugars and Base Pairing

View Details