What is Mitosis and Meiosis?
Mitosis and meiosis are the two ways cells divide — mitosis makes identical copies for growth and repair, while meiosis produces genetically varied sex cells for reproduction. Comparing them reveals how organisms both grow and pass on genetic diversity.
Mitosis is cell division that produces two genetically identical diploid cells for growth and repair, while meiosis is cell division that produces four genetically unique haploid gametes for sexual reproduction.
- •One division, two daughter cells
- •Genetically identical to parent cell
- •Diploid (2n) to diploid (2n)
- •Used for growth, repair, and asexual reproduction
- •No crossing over
- •Two divisions, four daughter cells
- •Genetically unique (recombination)
- •Diploid (2n) to haploid (n)
- •Used for producing gametes (sperm/eggs)
- •Crossing over occurs in prophase I
Step-by-step worked examples
A skin cell with 46 chromosomes divides by mitosis to repair a wound. How many chromosomes does each daughter cell have?
Mitosis produces two daughter cells genetically identical to the parent Chromosome number stays the same — no reduction occurs Each daughter cell has 46 chromosomes, same as the original skin cell
A human germ cell with 46 chromosomes undergoes meiosis to form gametes. How many chromosomes does each resulting sperm cell have?
Meiosis involves two rounds of division (meiosis I and II) The chromosome number is halved to produce haploid cells Each of the four resulting sperm cells has 23 chromosomes (46 ÷ 2)
Why do siblings from the same parents look different from each other, even though both were produced by meiosis from the same two parents?
Meiosis includes crossing over during prophase I, which shuffles genetic material between homologous chromosomes Independent assortment randomly distributes chromosomes into gametes These two processes create genetically unique gametes each time, so siblings inherit different combinations of genes
Flashcards
Quick quiz
Q1.Which process produces two genetically identical daughter cells?
Q2.How many daughter cells result from meiosis?
Q3.Where does crossing over occur?
Q4.If a parent cell has 46 chromosomes, how many chromosomes does each cell have after meiosis?
The full card deck, worked steps and AI-tutor support for “What is Mitosis and Meiosis?” are in Notek — study by hand before your exam.
Common mistakes
Thinking mitosis and meiosis both produce identical cells. — Correct: Only mitosis produces genetically identical cells; meiosis produces genetically unique gametes.
Believing meiosis has only one division, like mitosis. — Correct: Meiosis has two rounds of division (meiosis I and II), producing four cells total.
Assuming crossing over happens in mitosis too. — Correct: Crossing over is unique to prophase I of meiosis, not mitosis.
Confusing diploid and haploid outcomes. — Correct: Mitosis keeps cells diploid (2n); meiosis reduces cells to haploid (n).
FAQ
What is the difference between mitosis and meiosis?
Mitosis produces two identical diploid cells for growth and repair, while meiosis produces four genetically unique haploid gametes for reproduction.
What are examples of mitosis and meiosis?
Skin cells dividing to heal a cut is mitosis; the production of sperm and egg cells in reproductive organs is meiosis.
How many stages does meiosis have?
Meiosis has two main divisions, each with prophase, metaphase, anaphase, and telophase — meiosis I and meiosis II.
Why is meiosis important for genetic diversity?
Crossing over and independent assortment during meiosis shuffle genes, making every gamete genetically unique — a key driver of variation in offspring.