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.
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Read the Cell Structure and Function notesFree MDCAT chapter notes with key terms2,478 questions · page 102 of 124
2021. Euchromatin is _:
- A. The condensed part of a chromosome
- B. In a closed configuration
- C. Never condensed
- D. In an open configuration
Explanation: Heterochromatin and euchromatin are 2 types of chromatin. The key difference between heterochromatin and euchromatin is the packaging.
Correct answer: In an open configuration- A. Genetic information
- B. Yolk
- C. Cytoplasm
- D. Organelles
Explanation: Gametes are haploid and have a half set of chromosomes. During fertilization egg and sperm with an equal number of chromosomes fuse to…
Correct answer: Genetic information- A. DNA polymerase I
- B. DNA polymerase III
- C. DNA polymerase II
- D. DNA Ligase
Explanation: DNA polymerase III is the main replicating enzyme. It has two subunits.
Correct answer: DNA polymerase III- A. Towards replication fork
- B. Towards another DNA molecule
- C. Away from replication fork
- D. Towards other strand of DNA molecule
Explanation: Overall, the process of replication is always towards the replication fork.
Correct answer: Away from replication fork- A. Two heavy strands having N15
- B. Two light Strands having N14
- C. Hybrid possessing heavy and light each
- D. Not specified
Explanation: In the Meselson-Stahl experiment, after the first round of DNA replication, each daughter DNA duplex consists of a hybrid DNA molecule…
Correct answer: Hybrid possessing heavy and light each2026. Separation of variable DNA strands in Meselson-Stahl experiments is achieved due to variability in:
- A. Pentose sugars
- B. Bonding
- C. Phosphate groups
- D. Bases
Explanation: In Meselson-Stahl's experiment, radioactive isotopes of nitrogen were used.
Correct answer: Bases- A. Parent strand
- B. Lagging strand
- C. Leading strand
- D. None of these
Explanation: The leading strand is the strand of nascent DNA which is synthesised in the same direction as the growing replication fork.
Correct answer: Leading strand- A. 10-20 nucleotides
- B. 1000-2000 nucleotides
- C. 100-200 nucleotide
- D. Variable
Explanation: Okazaki fragments are DNA nucleotides sequence synthesized by DNA polymerase III during the replication of the lagging strand variable…
Correct answer: 1000-2000 nucleotides- A. DNA proof-reading
- B. DNA repair
- C. Unwinding
- D. Annealing
Explanation: DNA polymerase enzyme has three types: DNA polymerase-I is involved in proof-reading activities.
Correct answer: DNA repair- A. Codon
- B. Triplet code
- C. Anticodon
- D. Gene
Explanation: Genes are fundamental units of heredity, made of DNA, that carry instructions for building and operating living organisms, determining…
Correct answer: Gene- A. mRNA
- B. rRNA
- C. tRNA
- D. DNA
Explanation: During translation, the site where polypeptides (proteins) are assembled is provided by rRNA (ribosomal RNA).
Correct answer: rRNA- A. Promoter
- B. Initiation complex
- C. Aminoacyl-tRNA
- D. Polysome
Explanation: In prokaryotes, polypeptide synthesis begins with the formation of the initiation complex.
Correct answer: Initiation complex- A. Polymerase
- B. Elongation factor
- C. Initiation factor
- D. Release factor
Explanation: The translocation of ribosomes on mRNA during translation occurs due to elongation factors, not initiation factors, release factors, or…
Correct answer: Elongation factor- A. Condensation
- B. Polymerisation
- C. Replication
- D. Transcription
Explanation: DNA replication is the process by which a ds-DNA molecule is copied to produce two daughter DNA molecules.
Correct answer: Replication- A. Restriction endonuclease
- B. Primase
- C. DNA helicase
- D. DNA Ligase
Explanation: The enzyme that attaches the Okazaki fragments in the lagging strand during DNA replication is called DNA ligase.
Correct answer: DNA Ligase- A. One place only without any specific sequence of DNA
- B. One or more places without any specific sequence of DNA
- C. Any place with the uncoiling of two strands of DNA
- D. One or more places where there is a specific sequence of nucleotides
Explanation: The process of DNA replication begins at one or more places where there is a specific sequence of nucleotides.
Correct answer: One or more places where there is a specific sequence of nucleotides- A. DNA polymerase
- B. RNA polymerase
- C. DNA ligase
- D. Helicase
Explanation: The formation of a new strand of DNA from a template strand is the function of DNA polymerase.
Correct answer: DNA polymerase- A. Conservative idea
- B. Dispersive idea
- C. Disruptive idea
- D. Semi-conservative idea
Explanation: The above context is about the dispersive model of DNA replication. In the dispersive model, it was proposed that parental DNA strands…
Correct answer: Dispersive idea- A. 50% hybrid duplex and 50% light duplex
- B. 60% hybrid duplex and 40% heavy duplex
- C. 100% heavy duplex
- D. 100% hybrid duplex
Explanation: When Meselson and Stahl conducted their famous experiment, they used bacteria grown in a heavy isotope of nitrogen (N-15) medium, and then…
Correct answer: 50% hybrid duplex and 50% light duplex- A. 331
- B. 993
- C. 93
- D. 330
Explanation: To determine the number of amino acids in the polypeptide chain encoded by the mRNA sequence, divide the total number of nucleotides by 3…
Correct answer: 330