Free Cell Structure and Function MCQs with Answers
2,478 Cell Structure and Function MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Animal, plant, prokaryotic and eukaryotic cells are compared through their membranes, cell walls, nuclei and cytoplasmic organelles. The work includes the structures and functions of mitochondria, chloroplasts, ribosomes, endoplasmic reticulum, Golgi apparatus and lysosomes, as well as chromosome organization and the distinction between chromatin and chromosomes.
Last updated
Read the Cell Structure and Function notesFree MDCAT chapter notes with key terms2,478 questions · page 83 of 124
- A. RNA polymerase
- B. RNA primase
- C. RNA ligase
- D. RNA protease
Explanation: RNA ligase seals exons after introns are removed, producing a continuous coding sequence.
Correct answer: RNA ligase- A. L-shaped
- B. S-shaped
- C. Y-shaped
- D. E-shaped
Explanation: tRNA folds into an L-shape in 3D, fitting correctly into ribosomes during translation.
Correct answer: L-shaped- A. Formation of formyl-met-tRNA
- B. Binding of 30S subunit of ribosome with mRNA
- C. Association of 30S-mRNA with formyl-met-tRNA
- D. Association of 50S subunit of ribosome with initiation complex
Explanation: In prokaryotic translation initiation, a GTP molecule is required for the step where the 50S ribosomal subunit joins the 30S initiation…
Correct answer: Association of 50S subunit of ribosome with initiation complex- A. On plates with and without streptomycin
- B. On plates with minimal medium
- C. Only on plates with streptomycin
- D. Only on plates without streptomycin
Explanation: Imprints on both plates (with and without streptomycin) help identify streptomycin-resistant mutants by comparing growth patterns.
Correct answer: Only on plates with streptomycin- A. One DNA strand with another
- B. One nucleoside with another
- C. One nucleotide with another nucleotide
- D. One nitrogenous base with a pentose sugar
Explanation: Phosphodiester bonds connect 3′-OH of one sugar with 5′ phosphate of next nucleotide, forming the DNA backbone.
Correct answer: One nucleotide with another nucleotide- A. Codes for enzymes needed for DNA replication
- B. Codes for protein needed in cell cycle
- C. Does not code for proteins and is same in all members of population
- D. Shows high polymorphism in the population and is inherited
Explanation: Satellite DNA varies greatly among individuals. Its polymorphism is used in DNA fingerprinting, paternity tests, and forensic studies.
Correct answer: Shows high polymorphism in the population and is inherited- A. Centromere
- B. Chromatid
- C. Telomere
- D. Kinetochore
Explanation: The centromere is the constricted region joining the two sister chromatids and is essential for spindle attachment during cell division.
Correct answer: Centromere- A. Sugar-phosphate backbone
- B. Nitrogenous base
- C. Nucleotides
- D. Hydrogen bonds
Explanation: The sugar-phosphate backbone of DNA is formed by alternating deoxyribose sugar and phosphate groups linked by phosphodiester bonds.
Correct answer: Sugar-phosphate backbone- A. Sister Chromatid
- B. Centromere
- C. Chromatin
- D. Telomere
Explanation: The label X points to the tip (end) of the chromatid arm. Telomeres are the protective caps at the ends of chromosomes that prevent…
Correct answer: Telomere- A. Ligase
- B. Helicase
- C. Primase
- D. Polymerase
Explanation: Helicase is the enzyme responsible for unwinding and separating the two strands of the DNA double helix at the replication fork, creating…
Correct answer: Helicase- A. Template strand
- B. Coding strand
- C. Okazaki fragment
- D. Introns
Explanation: The transcription bubble is the unwound portion of DNA where RNA is being synthesized.
Correct answer: Template strand- A. DNA polymerase
- B. RNA polymerase
- C. Ligase
- D. Helicase
Explanation: RNA polymerase reads the DNA template strand and synthesizes a complementary RNA strand.
Correct answer: RNA polymerase- A. Strand A
- B. Strand B
- C. Both strands
- D. None
Explanation: The lagging strand is synthesized discontinuously in short segments called Okazaki fragments.
Correct answer: Strand B- A. DNA polymerase I
- B. Ligase
- C. Primase
- D. Topoisomerase
Explanation: During lagging strand synthesis, short DNA segments (Okazaki fragments) are produced.
Correct answer: Ligase- A. Acceptor arm
- B. Anticodon loop
- C. Variable arm
- D. D-loop
Explanation: The anticodon loop carries a sequence of three bases complementary to the mRNA codon.
Correct answer: Anticodon loop- A. Anticodon loop
- B. Acceptor stem (3′ end)
- C. D‑loop
- D. Variable arm
Explanation: The 3' end of tRNA always ends with the sequence CCA, where the amino acid binds.
Correct answer: Acceptor stem (3′ end)- A. Acrocentric
- B. Telocentric
- C. Sub metacentric
- D. Metacentric
Explanation: Acrocentric is defined as the position where centromere is present near the end.
Correct answer: Acrocentric- A. Histone
- B. Nucleosome
- C. Nucleolus
- D. None of the above
Explanation: Every 200 nucleotides, the DNA duplex is coiled around a core of eight histone proteins forming a complex known as a nucleosome which…
Correct answer: Nucleosome- A. Nucleosome
- B. Chromatin
- C. Chromosome
- D. All of the above
Explanation: Coiling occurs when the string of nucleosomes wraps up into higher order coils called super coils, which results in formation of chromatin.
Correct answer: Chromatin- A. Walter Sutton
- B. Oswald Avery
- C. Frederick Griffith
- D. Karl Correns
Explanation: The first evidence of the hereditary nature of DNA was provided by a British microbiologist Frederick Griffith who made some unexpected…
Correct answer: Frederick Griffith