Online Test — Molecular Basis of Inheritance
17 Questions • 15 min • Chapter MCQ
15:00
Question 1 of 17
The genetic material in almost all living organisms is:
Protein
DNA
Lipid
Starch
Explanation: DNA is the genetic material (RNA in some viruses).
Question 2 of 17
The building blocks (monomers) of DNA are:
Amino acids
Nucleotides
Fatty acids
Sugars only
Explanation: DNA is a polymer of nucleotides.
Question 3 of 17
Which sugar is present in DNA?
Ribose
Deoxyribose
Glucose
Sucrose
Explanation: DNA contains deoxyribose sugar.
Question 4 of 17
In DNA, guanine pairs with:
Adenine
Thymine
Cytosine
Uracil
Explanation: G pairs with C (and A with T).
Question 5 of 17
The double-helix model of DNA was proposed by:
Watson and Crick
Mendel
Darwin
Pasteur
Explanation: Watson and Crick proposed the double helix in 1953.
Question 6 of 17
Copying of DNA before cell division is called:
Translation
Replication
Transcription
Mutation
Explanation: DNA replication copies the DNA.
Question 7 of 17
DNA replication is:
Conservative
Semi-conservative
Dispersive only
Random
Explanation: Each new molecule keeps one old strand — semi-conservative.
Question 8 of 17
The enzyme that builds new DNA strands is:
DNA polymerase
Amylase
Pepsin
Lipase
Explanation: DNA polymerase synthesises the new strand.
Question 9 of 17
The central dogma is:
Protein → RNA → DNA
DNA → RNA → Protein
RNA → Protein → DNA
DNA → Protein
Explanation: Information flows DNA → RNA → Protein.
Question 10 of 17
Copying a gene from DNA into mRNA is:
Translation
Transcription
Replication
Mutation
Explanation: Transcription makes mRNA from DNA.
Question 11 of 17
In RNA, the base that replaces thymine is:
Adenine
Uracil
Cytosine
Guanine
Explanation: RNA uses uracil in place of thymine.
Question 12 of 17
Proteins are built from mRNA at the:
Nucleus
Ribosomes
Mitochondria
Cell wall
Explanation: Translation builds proteins at the ribosomes.
Question 13 of 17
A triplet of bases coding for one amino acid is a:
Gene
Codon
Genome
Chromosome
Explanation: A codon is three bases coding one amino acid.
Question 14 of 17
The genetic code being nearly the same in all organisms means it is:
Universal
Random
Useless
Single
Explanation: The code is universal, evidence of common ancestry.
Question 15 of 17
The complete set of an organism's DNA is its:
Genome
Codon
Allele
Ribosome
Explanation: The genome is all of an organism's DNA.
Question 16 of 17
The 'transforming principle' was first observed in the experiment of:
Griffith
Mendel
Darwin
Watson
Explanation: Griffith observed transformation in Streptococcus pneumoniae.
Question 17 of 17
The lac operon of E. coli is switched on in the presence of:
Lactose
Oxygen
Sunlight
Nitrogen
Explanation: Lactose induces the lac operon, turning on the digesting genes.