Free Cell Structure and Function MCQs with Answers

• A. 3.4 nm
• B. 0.3 nm
• C. 2 nm
• D. 0.2 nm

Explanation: The diameter of the DNA helix is 2 nm and the vertical rise per base pair is 0.34 nm.

• A. 430
• B. 142
• C. 426
• D. 460

Explanation: Each amino acid is coded by 3 nucleotides, hence to form a protein molecule of 142 amino acids, 142 multiplied by 3 nucleotides would be…

• A. 1
• B. 5
• C. 10
• D. 15

Explanation: The distance between two corresponding base pairs is 0.34 nm and a complete helix measures 3.4 nm in length.

• A. DNA and proteins
• B. Only DNA
• C. Only proteins
• D. RNA

Explanation: Evolutionary relationships among species are reflected in their DNA and proteins, in their genes and gene products.

• A. One
• B. Two
• C. Three
• D. Half

Explanation: Even when a chromosome is replicated, it has two sister chromatids. Each sister chromatid has one DNA molecule.

• A. Nucleosome
• B. Gene pool
• C. Karyotype
• D. Centromere

Explanation: Karyotyping is the process of pairing and ordering all the chromosomes of an organism, thus providing a genome-wide snapshot of an…

• A. Ligase
• B. Invertase
• C. Helicase
• D. Topoisomerase

Explanation: DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule

• A. Conservative
• B. Semi - conservative
• C. Dispersive
• D. New synthesis

Explanation: Each strand of original DNA serves as a template to form a new strand with one original and one replicated strand

• A. Two
• B. Three
• C. Four
• D. Five

Explanation: All eukaryotes have three different RNA polymerases (RNAPs) which transcribe different types of genes

• A. Single ; two
• B. Single ; three
• C. Triplet ; two
• D. Triplet ; three

Explanation: The genetic code has a triplet base. Nonsense codons are those that terminate the translation process since there are no corresponding…

• A. RNA polymerase
• B. Helicase
• C. Elongation factor
• D. Primase

Explanation: mRNAs are usually translated by a series of ribosomes, spaced at intervals of about 100 to 200 nucleotides.Elongation factors are a group…

• A. Position of a gene on the chromosome.
• B. Appearance of a trait in an individual
• C. Partner of a gene pair
• D. Gene in an individual for a trait

Explanation: A locus is the specific physical location of a gene or other DNA In genetics, a locus (plural: loci) refers to the specific position or…

• A. Hereditary
• B. Secretory
• C. Power house
• D. Food synthesis
• E. Protein formation

Explanation: Chromosomes are thread-like structures made up of DNA and proteins, and are present in the nucleus of eukaryotic cells.

• A. Epistasis
• B. Gene linkage
• C. Crossing over
• D. Pleiotropy
• E. Bombay Phenotype

Explanation: Gene linkage is a physical relationship of genes present on the same chromosome, which results in the tendency of the genes to be…

• A. Non-fusion
• B. Non-disjunction
• C. Fusion
• D. Interference

Explanation: Non-disjunction: It is the failure of the chromosomes to separate, which produces daughter cells of an abnormal number of chromosomes.

• A. Nucleus
• B. Nucleolus
• C. Cytoplasm
• D. Ribosomes

Explanation: Translation is the process of protein synthesis in which the ribosomes read the messenger RNA (mRNA) and use the information to synthesize…

• A. Release factors
• B. Methionine
• C. tRNA
• D. Amino acids

Explanation: Stop codons are sequences of nucleotides in the mRNA that signal the end of the protein-coding sequence.

• A. TAG
• B. AUG
• C. UAG
• D. AAA
• E. AGT

Explanation: UAG is one of the three stop codons, also known as termination codons, in the genetic code. The other two stop codons are UAA and UGA.

• A. Down
• B. Turner
• C. Klinefelter
• D. None of the above

Explanation: Turner syndrome is often not recognized until adolescence. Down syndrome and Klinefelter syndrome are typically recognized at birth.

• A. 4
• B. 10
• C. 24
• D. 23

Explanation: Humans contain 46 chromosomes in their cells, this number is diploid. The haploid number is half of the diploid number which is 23.