Cell Cycle and Cell Division — NEET Botany MCQs with answers

Cell Cycle and Cell Division is a Class 11 Botany chapter in the NEET (UG) syllabus. NEET720 has 714 reviewed practice questions on it, each with a quick answer and a step-by-step explanation. The 8 questions below are free and fixed, so you can bookmark this page; the full chapter, plus mistake tracking and spaced revision, is in the app.

Topics covered

Cell Cycle Phases · Mitosis · Meiosis · Mitosis vs Meiosis Comparisons · Significance of meiosis · Cell Division · Cell Cycle and Cell Division · Cell cycle checkpoints · Interphase · Mitosis phases · Cytokinesis in plants · Significance of mitosis · Meiosis significance · Meiosis phases · Meiosis I vs meiosis II · Meiosis outcome · Mitotic spindle · Mitotic checkpoints · Plant meristem cell cycle · Chromosome number terminology · Mitosis - prophase events · Independent assortment · Mitosis vs meiosis comparison · Cell cycle duration variability · Chromosome structure at metaphase · G2 phase · Interphase overview · Meiotic products in plants · Cell division errors · Cell cycle regulation · Amitosis · Cytokinesis · Meiosis vs mitosis · Cell cycle · Mitosis vs meiosis · Cell cycle and division · Cell cycle control · Applied cytology · Comparative division biology

8 free Cell Cycle and Cell Division practice questions with answers

Choose an answer in your head before opening it. Each explanation says why the correct option is right and, where relevant, why the tempting wrong option is wrong.

1. Question 1 · easy · Cell Cycle Phases

   In a typical dividing cell with a cell cycle duration of about 24 hours, interphase occupies approximately what fraction of the total cycle time?

   • A.About 30%
   • B.About 50%
   • C.About 95%
   • D.About 70%
   Show answer and explanation

   Answer: C. About 95%

   Interphase (G1+S+G2) is the longest phase of the cell cycle, occupying roughly 95% of total cycle duration.

   The cell cycle is divided into interphase (preparatory phase) and M phase (mitotic/division phase). Interphase includes G1 (growth), S (DNA replication) and G2 (further growth and preparation). Because a cell spends most of its time growing and preparing rather than actually dividing, interphase occupies about 95% of the cycle, while M phase takes up only about 5%. Options A, B and D underestimate this dominance.

   Common mistake: Assuming mitosis, being visually dramatic, occupies a large fraction of cycle time.

   Key point: Interphase is the longest phase, ~95% of the cell cycle; M phase is brief, ~5%.

2. Question 2 · medium · Cell Cycle Phases

   Which of the following best describes the principal cellular activity occurring during the G1 phase of the cell cycle?

   • A.DNA replication doubles the genetic content from 2C to 4C
   • B.The cell is metabolically active, grows, and synthesises RNA and proteins needed for later phases
   • C.The centriole duplicates in preparation for spindle formation
   • D.Karyokinesis followed by cytokinesis occurs
   Show answer and explanation

   Answer: B. The cell is metabolically active, grows, and synthesises RNA and proteins needed for later phases

   G1 is the growth phase before DNA synthesis: the cell increases in size and is metabolically active, synthesising RNA and proteins, but DNA replication has not yet begun.

   G1 (Gap 1) is the first sub-stage of interphase. The cell grows physically, becomes metabolically active, and synthesises RNA and proteins needed for later replication and division, but does not undergo DNA replication in this phase. Option A describes S phase. Option C describes an event associated with S phase in animal cells. Option D describes M phase.

   Common mistake: Assuming any interphase sub-stage involves DNA synthesis.

   Key point: G1: growth and biosynthesis, NOT DNA replication.

3. Question 3 · medium · Cell Cycle Phases

   The defining event of the S (synthesis) phase of the cell cycle is:

   • A.Formation of the cell plate or cleavage furrow
   • B.Nuclear envelope breakdown and spindle fibre formation
   • C.Separation of sister chromatids to opposite poles
   • D.DNA replication, during which the DNA content of the cell doubles while chromosome number remains unchanged
   Show answer and explanation

   Answer: D. DNA replication, during which the DNA content of the cell doubles while chromosome number remains unchanged

   S phase is when DNA synthesis (replication) occurs; the DNA content doubles from 2C to 4C, but the chromosome number stays the same because each chromosome now consists of two sister chromatids.

   During S phase, DNA replicates and histone protein synthesis also occurs; the amount of DNA per cell doubles from 2C to 4C, but the number of chromosomes does not change because replication produces two identical sister chromatids joined at the centromere within the same chromosome. Options B, C and D describe events of mitosis (prophase, anaphase and cytokinesis respectively), not interphase.

   Common mistake: Believing chromosome number doubles in S phase (only chromatid/DNA content doubles).

   Key point: S phase: DNA content 2C to 4C, chromosome number unchanged.

4. Question 4 · medium · Cell Cycle Phases

   After DNA replication is complete, a cell enters G2 phase. What is the main significance of this phase?

   • A.It is when chromosome number is reduced to half in preparation for gametogenesis
   • B.It is when the cell replicates its DNA a second time to ensure fidelity
   • C.Protein synthesis continues and the cell grows further, preparing the machinery needed for mitosis
   • D.It is when karyokinesis is completed and the nucleus divides into two
   Show answer and explanation

   Answer: C. Protein synthesis continues and the cell grows further, preparing the machinery needed for mitosis

   G2 is a growth and preparatory phase following DNA replication, during which protein synthesis continues and the cell readies itself for mitosis.

   G2 (Gap 2) follows S phase. Although DNA has already been replicated, the cell continues to grow and synthesise proteins, including those required for spindle apparatus formation, in preparation for M phase. Option A describes meiosis I, not G2 of the mitotic cycle. Option B is factually wrong, as DNA replicates only once per cycle (in S phase). Option D describes M phase itself, not the preparatory G2 stage.

   Common mistake: Thinking G2 involves another round of DNA replication.

   Key point: G2: growth and protein synthesis in preparation for mitosis, after DNA has already doubled.

5. Question 5 · easy · Cell Cycle Phases

   The M phase (mitotic phase) of the cell cycle is best described as consisting of which sequential events?

   • A.S phase followed by G2 phase
   • B.Cytokinesis followed by DNA replication
   • C.G1 phase followed by G0 phase
   • D.Karyokinesis (nuclear division) followed by cytokinesis (cytoplasmic division)
   Show answer and explanation

   Answer: D. Karyokinesis (nuclear division) followed by cytokinesis (cytoplasmic division)

   M phase, the actual division phase, comprises karyokinesis (division of the nucleus) followed by cytokinesis (division of the cytoplasm), producing two daughter cells.

   M phase is the most dramatic stage of the cell cycle, during which the cell actually divides. It begins with karyokinesis, the division of the nucleus (comprising prophase, metaphase, anaphase and telophase in mitosis), and is generally followed by cytokinesis, the division of the cytoplasm, resulting in two daughter cells. Options A and C wrongly include interphase sub-stages within M phase, and Option D reverses the correct order and misplaces DNA replication, which occurs earlier in S phase.

   Common mistake: Mixing up interphase sub-stages (G1, S, G2) with the events of M phase.

   Key point: M phase = karyokinesis then cytokinesis.

6. Question 6 · medium · Cell Cycle Phases

   Statement I: The chromosome number of a cell remains 2n throughout interphase, including after S phase. Statement II: Although chromosome number is unchanged after S phase, the chromatid number effectively doubles because each chromosome now consists of two sister chromatids. Choose the correct option.

   • A.Statement I is false but Statement II is true
   • B.Statement I is true but Statement II is false
   • C.Both Statement I and Statement II are false
   • D.Both Statement I and Statement II are true
   Show answer and explanation

   Answer: D. Both Statement I and Statement II are true

   Chromosome number stays 2n through all of interphase, including after S phase; what changes is the chromatid count per chromosome, which doubles from one to two sister chromatids.

   DNA replication in S phase does not create new, separate chromosomes; instead, each chromosome duplicates to form two sister chromatids joined at a common centromere, still counted as a single chromosome. Therefore, chromosome number remains constant at 2n throughout interphase (G1, S, G2). What increases is the chromatid number, from one chromatid per chromosome before S phase to two sister chromatids per chromosome after S phase. Both statements correctly describe this relationship.

   Common mistake: Confusing chromosome number doubling with chromatid number doubling.

   Key point: Chromosome number stays 2n through interphase; chromatid number per chromosome doubles after S phase.

7. Question 7 · medium · Cell Cycle Phases

   A biologist examines mature, fully differentiated neurons and finds they never re-enter mitosis under normal physiological conditions. Which phase of the cell cycle are these neurons best described as having exited into?

   • A.S phase, permanently arrested mid-replication
   • B.G2 phase, awaiting an external division signal
   • C.M phase, held at metaphase indefinitely
   • D.G0 phase, a quiescent stage exited from G1
   Show answer and explanation

   Answer: D. G0 phase, a quiescent stage exited from G1

   Terminally differentiated, non-dividing cells such as neurons exit the active cell cycle from G1 into the quiescent G0 stage, remaining metabolically active but not proliferating.

   Cells that complete differentiation and lose the need or capacity to divide further exit the cell cycle at G1 and enter G0, a quiescent but metabolically active stage. Neurons are a classic NCERT example of cells in G0. Options A, B and C incorrectly place the exit within active replication, growth-arrest before mitosis, or mid-mitosis, none of which describe the biologically accurate resting stage.

   Common mistake: Placing non-dividing cells in G2 or M phase rather than the correct G0 exit point from G1.

   Key point: Non-dividing differentiated cells like neurons reside in G0, exited from G1.

8. Question 8 · medium · Cell Cycle Phases

   In animal cells, duplication of the centriole occurs during which phase of the cell cycle?

   • A.S phase, concurrent with DNA replication
   • B.G1 phase, before DNA replication begins
   • C.G2 phase, just before mitosis begins
   • D.M phase, during prophase itself
   Show answer and explanation

   Answer: A. S phase, concurrent with DNA replication

   Centriole duplication in animal cells occurs during S phase, alongside DNA replication, not in G1, G2 or M phase.

   S phase is defined by DNA synthesis, but in animal cells it also features duplication of the centriole, so that by the time the cell enters mitosis, two pairs of centrioles are available to organise the two spindle poles. This is a commonly tested fine-grained NEET fact, since students often assume centriole duplication happens closer to division (G2 or M phase) rather than earlier alongside DNA replication in S phase.

   Common mistake: Placing centriole duplication in G2 because it 'prepares for mitosis'.

   Key point: Centriole duplication is an S-phase event, not a G2 or M-phase event.

Questions about Cell Cycle and Cell Division for NEET

More Botany chapters

← BiomoleculesAll Botany chaptersBiological Classification →

Questions are original NEET720 compositions reviewed for correctness, syllabus fit and option quality. Counts update as the bank grows (714 active practice questions in this chapter today).