Free Cell Structure and Function MCQs with Answers

• A. One strand turns clockwise
• B. One strand turns anti­-clockwise
• C. The phosphate groups of two DNA strands, at their ends, share the same position
• D. The phosphate groups at the start of two DNA strands are in opposite positions (poles)

Explanation: DNA is a type of nucleic acid that forms genetic material in many organisms.

• A. A polypeptide of 24 amino acids will be formed.
• B. Two polypeptides of 24 and 25 amino acids will be formed.
• C. A polypeptide of 49 amino acids will be formed.
• D. A polypeptide of 25 amino acids will be formed.

Explanation: UGA, UAG and UAA are three non sense (or termination) codons which do not code for any amino acid.

• A. Ligase
• B. Primase
• C. DNA polymerase
• D. Endonuclease

Explanation: DNA ligase is a type of enzyme that catalyses the formation of a phosphodiester bond between two DNA molecules.

• A. repetitive DNA
• B. RNA
• C. single copy DNA
• D. none of these

Explanation: Single copy DNA - because most protein-coding genes are present in the unique (single-copy) regions of the genome, while repetitive DNA…

• A. F. Sanger
• B. Beadle
• C. Tatum
• D. Ingram

Explanation: Ingram because Vernon Ingram discovered that sickle cell anaemia results from a single amino acid substitution (glutamic acid → valine) in…

• A. GGGAUCUC
• B. GGGATCTC
• C. GGAAUCUC
• D. GGGGTCTC

Explanation: C pairs with G, A pairs with T in DNA, while A pairs with U in RNA. The question asks for the corresponding mRNA sequence after…

• A. DNA polymerase
• B. DNA ligase
• C. Reverse transcriptase
• D. All of these

Explanation: Reverse Transcriptase is an enzyme that uses single-stranded RNA as a template to synthesize complementary double-stranded DNA (cDNA).This…

• A. Chromatic body
• B. Nuclear region
• C. Nuclear Body
• D. All of above

Explanation: Nucleotides are present in chromosomes that are located in the nucleus.

• A. Haploid
• B. Diploid
• C. Single nucleus
• D. None of these

Explanation: Diploid organisms have cells with two sets of chromosomes (2n), one set inherited from each parent.

• A. RNA Polymerase
• B. tRNA synthetase
• C. Aminocyle-tRNA synthetase
• D. tRNA ligase

Explanation: So, when it comes to linking a specific amino acid with its corresponding tRNA molecule during protein synthesis, there's a special enzyme…

• A. It should be able to express itself in the form of 'Mendelian characters
• B. It should be able to generate its replica
• C. It should be unstable structurally and chemically
• D. It should provide the scope for slow changes that are required for evolution

Explanation: Genetic material should be structurally and chemically stable; otherwise, its expression will change.

• A. Lactose
• B. Lactose and Galactose
• C. Glucose
• D. Galactose

Explanation: In the Lac operon, lactose is an inducer. It binds with a suppressor and inactivates it.

• A. tRNA^Val
• B. tRNA^Glu
• C. tRNA^Met
• D. tRNA^Lys

Explanation: tRNA^Val is the correct answer. Sickle cell anemia is caused by a single amino acid substitution in the beta-globin chain of hemoglobin…

• A. Double bond
• B. Phosphodiester bonds
• C. Covalent bond
• D. Hydrogen bond
• E. Single bond

Explanation: Each chain of DNA is formed by the union of many nucleotides through phosphodiester bonds. Phosphodiester bonds are covalent bonds.

• A. Genetic code
• B. Chromosome
• C. Amino acid
• D. Helix

Explanation: The correct answer is A Genetic code. Genetic information in DNA is stored in the form of a genetic code.

• A. Genes
• B. Phenotypes
• C. Karyotypes
• D. Cells

Explanation: DNA stores biological information in discrete units called genes. Genes are segments of DNA that contain the instructions for building and…

• A. Double Stranded binding proteins
• B. Double-stranded binding enzymes
• C. Single-stranded binding proteins
• D. Single-stranded binding enzyme

Explanation: Single-stranded (SSBs) are proteins that bind to single-stranded DNA during processes such as DNA replication and repair.

• A. 3rd position
• B. 6h position
• C. 5th position
• D. 4th position

Explanation: The sixth position of the beta globin chain of the hemoglobin molecule is where glutamic acid is replaced by valine.

• A. Basic amino acid
• B. Acidic fatty acid
• C. Başic citric acid
• D. Acidic amino acid

Explanation: Basic amino acids are amino acids that have a positively charged side chain at physiological pH (around 7.4), due to the presence of an…

• A. Gene
• B. Nucleosome
• C. Centrosome
• D. Centromere

Explanation: A centromere is a region of a chromosome that plays a critical role during cell division.