Free Cell Structure and Function MCQs with Answers

• A. Myoglobin
• B. Actin
• C. Tubulin
• D. Myosin

Explanation: Spindle fibers are microtubules made of 𝜶-and β-tubulin proteins; they do not contain RNA.

• A. Leptotene
• B. Pachytene
• C. Zygotene
• D. Diakinesis

Explanation: In diakinesis, chromosomes are maximally condensed and homologous chromosomes begin separating at chiasmata.

• A. Prophase
• B. Anaphase
• C. Metaphase
• D. Telophase

Explanation: Anaphase I of meiosis separates homologous chromosomes while sister chromatids remain together.

• A. Prophase
• B. Metaphase
• C. Anaphase
• D. Telophase

Explanation: In metaphase, spindle fibers attach to centromeres and chromosomes align at the metaphase plate.

• A. Rudolph Virchow
• B. F. Griffith
• C. Watson & Crick
• D. Hershey & Chase

Explanation: Rudolf Virchow stated "Omnis cellula e cellula" in 1855, meaning all cells arise from pre-existing cells.

• A. Growth Curve
• B. Cell Cycle
• C. Cell Growth Hypothesis
• D. One Gene - One Enzyme Hypothesis

Explanation: The cell cycle includes cell growth, DNA replication, mitosis. and cytokinesis.

• A. Interphase
• B. Prophase
• C. G-0 Phase
• D. G-1 Phase

Explanation: Interphase is the resting phase where the cell grows, duplicates DNA, and prepares for division.

• A. G-0 Phase
• B. G-1 Phase
• C. S Phase
• D. Both A and B

Explanation: DNA synthesis occurs only in S phase; G-1 and G-0 do not involve DNA replication.

• A. G-0 Phase
• B. G-1 Phase
• C. S Phase
• D. Mitotic Phase

Explanation: G-0 phase cells are metabolically active but have exited the cell cycle.

• A. G-0 Phase
• B. G-1 Phase
• C. S Phase
• D. Mitotic Phase

Explanation: S phase is when DNA replication occurs, forming identical sister chromatics.

• A. G-0 Phase
• B. G-1 Phase
• C. G-2 Phase
• D. S Phase

Explanation: G-1 phase duration varies among cells; some quickly enter S phase, others stay longer or enter G-0.

• A. G-1, G-2, S
• B. S, G-1, G-2
• C. G-1, S, G-2
• D. G-2, S, G-1

Explanation: Interphase sequence: G-1 (growth)--->S (DNA replication) --->G-2 (preparation for mitosis).

• A. After completion of interphase, mitosis is a dynamic and vigorous process
• B. Cytokinesis is usually followed by karyokinesis
• C. S sub-stage is followed by G-1
• D. Both B and C

Explanation: B is wrong: cytokinesis follows karyokinesis. C is wrong: sequence is G-1--->S---> G-2---> M

• A. Amitosis
• B. Mitosis
• C. Meiosis
• D. Interphase

Explanation: Amitosis is direct cell division without spindle formation or chromosome condensation.

• A. S­-phase
• B. G-1 phase
• C. G-2 phase
• D. M-phase

Explanation: In S-phase, DNA replicates, doubling the genetic material for division.

• A. G-1/S
• B. G-2/M
• C. M
• D. Both G-2/M and M

Explanation: The G-2/M checkpoint ensures DNA repication is complete before mitosis; a stalled fork triggers this checkpoint.

• A. Centromere
• B. Kinetosome
• C. Telomere
• D. Kinetochores

Explanation: Kinetochore is a protein complex on centromere where spindle fibers attach for chromosome movement.

• A. Chromosome movement
• B. Synapsis
• C. Spindle fibres
• D. Disappearance of nucleolus

Explanation: Synapsis occurs only in meiosis where homologous chromosomes pair. In mitosis, chromosomes do not pair, so synapsis is not a characteristic.

• A. Zygotene
• B. Diplotene
• C. Pachytene
• D. Leptotene

Explanation: Pachytene is when non-sister chromatids exchange. segments at chiasmata.

• A. Twice the chromosomes & four times the DNA
• B. Four times the chromosomes & twice the DNA
• C. Twice the chromosomes & same DNA
• D. Same chromosomes & twice the DNA

Explanation: After S-phase, diploid somatic cell has replicated DNA: 2x chromosomes and 4x DNA content compared to gametes.