Free Cell Structure and Function MCQs with Answers

• A. Nucleoside
• B. Gene
• C. Chromosomes
• D. Nucleotides

Explanation: A gene is a specific sequence of DNA (or RNA in some viruses) that contains the information necessary to produce a functional product…

• A. Transcription
• B. Replication
• C. Translation
• D. None

Explanation: Transcription is the process by which an RNA molecule is synthesized from a DNA template.

• A. Non-sense codon
• B. Stop codon
• C. Both (A) and (B)
• D. Promoters

Explanation: Non-sense codons, also known as stop codons, are specific sequences of three nucleotides (in DNA or mRNA) that signal the termination of…

• A. None
• B. Ligases
• C. Nucleases and phosphatases
• D. Polymerases

Explanation: Nucleases are enzymes that degrade nucleic acids, while phosphatases remove phosphate groups from molecules.

• A. Cancer
• B. Phenylketonuria
• C. Sickle cell anemia
• D. All

Explanation: In 1956, Vernon Ingram's discovery focused specifically on the molecular basis of sickle cell anemia.

• A. Antisense
• B. Sense
• C. Both (A) and (B)
• D. Coding

Explanation: This term refers to the non-coding DNA strand also called template strand that serves as the template for RNA synthesis during…

• A. Point mutation
• B. Line mutation
• C. Stop mutation
• D. None

Explanation: This occurs when a single nucleotide base is changed, inserted, or deleted from a DNA or RNA sequence.

• A. Polymerase III
• B. Primase
• C. DNA ligase
• D. Synthatase

Explanation: Primase is an enzyme responsible for synthesizing RNA primers during DNA replication.

• A. Ionic bond
• B. Hydrophobic interaction
• C. Phosphodiester bond
• D. None

Explanation: The overall stability of DNA is primarily due to the phosphodiester bond.

• A. P.A. Levene
• B. Watson and Crick
• C. F. Miescher
• D. Franklin

Explanation: Friedrich Miescher, a Swiss biologist, is credited with the first isolation of DNA in 1869.

• A. Lysine, serine
• B. Lysine, glutamine
• C. Arginine, lysine
• D. Arginine, proline

Explanation: Both arginine and lysine have positively charged side chains, making this option correct.

• A. 60% - 30%
• B. 20% - 80%
• C. 40% - 60%
• D. 90% - 10%

Explanation: Chromosomes are composed of DNA and protein. Most are about 40% DNA and 60% protein.

• A. 10
• B. 1000
• C. 40 million
• D. 140 million

Explanation: A typical human chromosome contains about 140 million (1.4x108) nucleotides in its DNA.

• A. 3'
• B. 5'
• C. Both
• D. None

Explanation: Another feature of DNA polymerase III is that it can add nucleotides only to the 3' end of a DNA strand.

• A. Meselson and Stahl
• B. DNA polymerases
• C. S form
• D. Locus

Explanation: The "S" form of Streptococcus pneumoniae refers to the smooth, encapsulated form of the bacterium.

• A. Locus
• B. DNA polymerases
• C. DNA model
• D. Meselson and Stahl

Explanation: The DNA model refers to the structure of DNA, which was elucidated by James Watson and Francis Crick in 1953.

• A. Locus
• B. Meselson and Stahl
• C. DNA polymerases
• D. S form

Explanation: DNA polymerases are enzymes responsible for catalyzing the synthesis of DNA molecules from nucleotides during DNA replication.

• A. 1 chromosome pair
• B. Drosophila
• C. Nucleotide
• D. F. Miescher

Explanation: Penicillium, a fungus, has only one pair of chromosomes.

• A. Open configuration
• B. Nucleotide
• C. F. Miescher
• D. 1 chromosome pair

Explanation: Euchromatin refers to the less condensed form of chromatin, which is the complex of DNA and proteins found in the nucleus of eukaryotic…

• A. 1 chromosome pair
• B. Nucleotide
• C. F. Miescher
• D. Drosophila

Explanation: Drosophila, particularly Drosophila melanogaster, is closely associated with T.H. Morgan.