Free Molecular Biology MCQs with Answers
38 Molecular Biology MCQs from Biochemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
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- A. DNA polymerase
- B. Reverse transcriptase
- C. RNA polymerase
- D. Phospho kinase
Explanation: Reverse transcriptase synthesises DNA using an RNA template, producing a complementary DNA strand and ultimately a double-stranded DNA…
Correct answer: Reverse transcriptase- A. Protein storage
- B. m RNA synthesis
- C. Modification of proteins
- D. t RNA synthesis
Explanation: The Golgi apparatus modifies, sorts, and packages proteins received from the endoplasmic reticulum, including glycosylation and…
Correct answer: Modification of proteins- A. Mitochondria
- B. Golgi bodies
- C. Nucleus
- D. Poly ribosomes
Explanation: Protein synthesis occurs on ribosomes, and multiple ribosomes translating the same mRNA form a polyribosome or polysome.
Correct answer: Poly ribosomes- A. Mitochondria
- B. Endoplasmic reticulum
- C. Nucleolus
- D. Plasma membrane
Explanation: Most cytoplasmic ribosomes are attached to the rough endoplasmic reticulum, where they synthesise proteins destined for secretion…
Correct answer: Endoplasmic reticulum- A. Protein lipid synthesis
- B. Protein synthesis
- C. Sorting of glycoproteins
- D. None of the above
Explanation: The Golgi apparatus modifies, sorts, and packages glycoproteins for delivery to their correct destinations.
Correct answer: Sorting of glycoproteins- A. Centriole
- B. Golgi body
- C. Endoplasmic reticulum
- D. Mitochondrion
Explanation: Mitochondria contain their own circular DNA and replicate semi-autonomously.
Correct answer: Mitochondrion- A. Lysomes
- B. Rough endoplasmic reticulum
- C. Golgi apparatus
- D. Mitochondria
Explanation: Lysosomes function as the cell’s digestive compartments because their acid hydrolases degrade proteins, lipids, nucleic acids, and…
Correct answer: Lysomes- A. c AMP
- B. c GMP
- C. Phosphatidyl glycerol
- D. Phosphatidyl inosital
Explanation: Phosphatidylglycerol is a membrane phospholipid and is not a standard second messenger.
Correct answer: Phosphatidyl glycerol- A. Ribsomes
- B. Nucleolus
- C. Golgi apparatus
- D. Nucleus
Explanation: The nucleus contains the cell's nuclear DNA and is therefore the expected answer among these options.
Correct answer: Nucleus- A. G Proteins act as inhibitory and excitatory because of difference in alpha subunit
- B. All the three subunits alpha, beta and gamma should bind each other for G protein to act
- C. G proteins bind to hormones on the cell surface
- D. G protein is bound to GTP in resting stateOrder DNA Kits
Explanation: G-protein effects can be stimulatory or inhibitory largely because different alpha subunits activate or inhibit target enzymes such as…
Correct answer: G Proteins act as inhibitory and excitatory because of difference in alpha subunit- A. Integrin a6-B4
- B. The catenins desmoplakin
- C. cadherins desmoglein
- D. a and B catenin
Explanation: Hemidesmosomes use integrin α6β4 to attach epithelial cells to laminin in the basal lamina.
Correct answer: Integrin a6-B4- A. Watson and Crick
- B. Edwarg Angle
- C. Singer and Nicolson
- D. G.V Black
Explanation: Singer and Nicolson proposed the fluid mosaic model in 1972, describing proteins floating within a dynamic phospholipid bilayer.
Correct answer: Singer and Nicolson- A. Immunofluoresence
- B. Widal test
- C. Electrophoresis
- D. Real time PCR
Explanation: Real-time PCR quantitatively amplifies and detects viral nucleic acid, allowing estimation of viral load.
Correct answer: Real time PCR- A. Cyclic AMP
- B. Cyclic GMP
- C. Adenosine cyclate
- D. Calcium release
Explanation: FSH, LH and TSH bind G-protein-coupled receptors that activate adenylate cyclase, increasing cyclic AMP as the second messenger.
Correct answer: Cyclic AMP- A. Post transcriptional modification
- B. Post translation modification
- C. DNA replication
- D. Splicing
Explanation: RNA directly participates in post-transcriptional processing, splicing, and DNA replication through RNA primers.
Correct answer: Post translation modification- A. Mitochondria
- B. Centrosome
- C. Nucleus
- D. Ribosome
Explanation: Translation is the ribosome-mediated reading of mRNA to assemble an amino-acid chain.
Correct answer: Ribosome- A. m-RNA
- B. DNA
- C. t-RNA
- D. Ribosomal RNA
Explanation: Codons are three-base sequences on mRNA that specify amino acids or stop signals during translation.
Correct answer: m-RNA18. The portion of DNA in Which RNA polymerase binds and starts transcription is called______________?
- A. Terminator
- B. Promoter region
- C. Operator
- D. Anti terminator
Explanation: The promoter is the DNA region recognized by RNA polymerase to begin transcription.
Correct answer: Promoter region- A. Degenerate
- B. Universal
- C. Punctuation
- D. Non overlapping
Explanation: The genetic code is degenerate, largely universal and non-overlapping, but it is comma-less, meaning there are no punctuation marks…
Correct answer: Punctuation- A. Nucleolus
- B. Nucleus
- C. Ribosome
- D. Endoplasmic reticulum
Explanation: Most ribosomal RNA is transcribed and processed in the nucleolus, where ribosomal subunits begin to assemble.
Correct answer: NucleolusMolecular Biology MCQs: common questions
Are these Molecular Biology MCQs free?
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How many Molecular Biology MCQs are on this page?
There are 38 Molecular Biology MCQs in the Biochemistry bank, shown 20 to a page with the correct answer and an explanation on each.
Does every Molecular Biology MCQ have an explanation?
Yes. Each Molecular Biology question shows the correct option and a written explanation of why it is correct, so a wrong answer teaches you something rather than just being marked wrong.
Can I take a timed Molecular Biology test?
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