Mitosis & the Cell Cycle — Practice · Grade 10 Science

Chapter: Cell Division, Reproduction & Development

What this practice covers

By the end of Mitosis & the Cell Cycle you should be able to:

10 questions, multiple choice, numeric and written answer, each with a worked explanation.

Vocabulary used: cell cycle, interphase, mitosis, sister chromatids, cytokinesis, daughter cell, centromere, G₁, S and G₂.

Problem 1

In the standard model without new copying errors, what is the main result of mitosis followed by cytokinesis?
  1. Two genetically identical daughter cells
  2. Four sex cells with half the DNA
  3. A cell with double the normal chromosome number
  4. A finished protein
Answer and explanation

Two genetically identical daughter cells

Mitosis produces two daughter cells genetically identical to the parent, used for growth and repair.

Problem 2

Which is the correct order of the phases of mitosis?
  1. Anaphase, Metaphase, Prophase, Telophase
  2. Prophase, Metaphase, Anaphase, Telophase
  3. Metaphase, Prophase, Anaphase, Telophase
  4. Telophase, Anaphase, Metaphase, Prophase
Answer and explanation

Prophase, Metaphase, Anaphase, Telophase

The order is Prophase, Metaphase, Anaphase, Telophase — remembered as PMAT.

Problem 3

Starting from a single cell, how many cells exist after 5 rounds of mitosis?
Answer and explanation

32 cells

Each round doubles the count: 2^5 = 32 cells.

Problem 4

Explain why a cell must copy its DNA during interphase before it divides by mitosis.
Answer and explanation

Copying the DNA first means there are two complete sets of chromosomes to distribute, so when the cell splits, each daughter cell receives a full, identical set rather than half of one.

Problem 5

How is cancer related to the cell cycle?
  1. Cells begin making sex cells instead of body cells
  2. DNA is no longer copied before division
  3. Mutations damage the genes that control the cell cycle, so cells divide uncontrollably and ignore normal stop signals
  4. The cell cycle stops completely and no cells ever divide again
Answer and explanation

Mutations damage the genes that control the cell cycle, so cells divide uncontrollably and ignore normal stop signals

Cancer arises when the checkpoint-control genes are mutated, letting cells divide out of control instead of stopping when they should.

Problem 6

A diploid cell has 12 chromosomes before replication. How many chromosomes does each daughter cell normally have after mitosis and cytokinesis? Explain the reasoning in your own words.
Answer and explanation

Each daughter normally has 12 chromosomes in this model.

Replication makes sister chromatids without changing the stated chromosome number.

Normal separation gives each daughter the original set size.

Response criteria

  • Use the stated conditions.
  • Show the evidence or calculation.
  • Explain the conclusion and any stated limitation.

Problem 7

A diploid cell has 12 chromosomes. What count is expected after normal mitosis in each daughter? Show the reasoning, not just the conclusion.
Hints

Chromatid doubling after replication is not a doubling of chromosome count when counted by centromeres.

Answer and explanation

12 chromosomes in each daughter.

Problem 8

Why do checkpoints matter before division?
Hints

State what the supplied observations or conditions establish, and separate that from any assumption.

Answer and explanation

They help coordinate replication, DNA integrity and segregation; failures can permit abnormal growth or chromosome errors.

Problem 9

Checkpoints regulate progression instead of promising perfect copyingCheckpoints regulate progression instead of promising perfect copyingDNA damage / signalsCheck before progressionRepair, pause or stopnot automatic divisionRegulation involves multiple pathways and responses.
Original control-decision abstraction, not a cancer diagnostic model or exhaustive checkpoint network.
Interpret the supplied visual. Does the mere observation of cell division establish failed regulation?
Answer and explanation

No. Division is also part of normal growth and renewal; interpretation needs the conditions, tissue behavior and regulatory evidence.

A checkpoint is a regulatory interaction that coordinates progression with conditions such as DNA integrity and spindle attachment. Repair, arrest and other responses can limit the propagation of damage. Cancer involves altered growth regulation and additional changes in cellular behavior; a single missed checkpoint is not a complete diagnosis or explanation of every tumor. Rate and timing differ among tissues. A cell-cycle diagram should show controlled transitions and distinguish damaged DNA, attempted repair and the later fate of the cell.

No. Division is also part of normal growth and renewal; interpretation needs the conditions, tissue behavior and regulatory evidence.

Response criteria

  • Read the structures, axes, directions and units correctly.
  • Connect the evidence with the biological mechanism.
  • Respect stated model assumptions and distinguish an observation from a further inference.

Problem 10

A diploid model starts with 10 chromosomes. Track chromosomes, chromatids and daughter-cell chromosome number through replication and normal mitosis/cytokinesis.
Answer and explanation

After S phase there are 10 replicated chromosomes and 20 chromatids; during separation each former chromatid becomes a chromosome. Each daughter receives 10 chromosomes, preserving diploidy in the model.

After S phase there are 10 replicated chromosomes and 20 chromatids; during separation each former chromatid becomes a chromosome. Each daughter receives 10 chromosomes, preserving diploidy in the model.

Response criteria

  • Use the stated measurements or conditions, with correct units.
  • Connect the result to the biological mechanism or evidence relationship.
  • Identify the assumption, model limit or further evidence requested.

Browse all courses