Practice questions on the structure of DNA, the double helix model, and how DNA is packaged into nucleosomes and chromatin. Useful for genetics exam preparation.
A missense mutation occurs when a nucleotide change results in a different amino acid being incorporated into the protein.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance DNA Structure Double Helix and Packaging - Nucleosome
Histone proteins help in the packaging of DNA into chromatin by forming nucleosomes.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance DNA Structure Double Helix and Packaging - Nucleosome
A nonsense mutation introduces a premature stop codon, leading to an incomplete protein.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance DNA Structure Double Helix and Packaging - Nucleosome
Helicase unwinds the DNA double helix, allowing replication to proceed.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance DNA Structure Double Helix and Packaging - Nucleosome
Enhancers are DNA sequences that increase transcription efficiency by binding activator proteins.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance DNA Structure Double Helix and Packaging - Nucleosome
A frameshift mutation alters the reading frame, leading to incorrect amino acid sequences.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance DNA Structure Double Helix and Packaging - Nucleosome
A nonsense mutation results in a premature stop codon, leading to incomplete protein synthesis.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance DNA Structure Double Helix and Packaging - Nucleosome
DNA consists of two antiparallel strands forming a double helix, with complementary base pairing (A-T, G-C).
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance DNA Structure Double Helix and Packaging - Nucleosome
Histones are only found in eukaryotic cells, as prokaryotic DNA lacks histones.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance DNA Structure Double Helix and Packaging - Nucleosome
Unlike eukaryotic DNA, prokaryotic DNA is not associated with histone proteins for packaging.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance DNA Structure Double Helix and Packaging - Nucleosome
Aminoacyl-tRNA synthetase catalyzes the attachment of an amino acid to its corresponding tRNA.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance DNA Structure Double Helix and Packaging - Nucleosome
A nucleosome helps package DNA into a compact structure by wrapping it around histone proteins.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance DNA Structure Double Helix and Packaging - Nucleosome
