Explain the role of meiotic cell division, including the production of…

The idea

Meiosis is a type of cell division that produces gametes (sex cells) such as sperm, egg cells and pollen. One parent cell divides to give four daughter cells. Each daughter cell receives half the number of chromosomes of the parent cell, so it is haploid rather than diploid. Because the chromosomes are shared out and recombined, the four gametes are genetically different from one another and from the parent cell. This variation is the role of meiosis: it makes gametes that carry different combinations of alleles, so offspring formed at fertilisation are not identical to each other or to their parents. You do not need to learn the individual stages of meiosis; focus on the outcome — four haploid, genetically different gametes.

What earns the marks

• Meiosis produces gametes (sex cells).
• One cell divides to form four daughter cells.
• Each daughter cell has half the number of chromosomes of the parent cell (haploid).
• The gametes produced are genetically different from each other.
• The variation arises because chromosomes/alleles are shared out and recombined.
• The stages of meiosis are not required knowledge.

Common mistakes and how to put them right

• Saying meiosis produces two daughter cells.

  Put it right: It produces four.

• Saying daughter cells have the same chromosome number as the parent.

  Put it right: They have half, so they are haploid.

• Confusing meiosis with mitosis.

  Put it right: Mitosis gives genetically identical diploid cells for growth, meiosis gives genetically different haploid gametes.

• Claiming the four gametes are identical.

  Put it right: They are genetically different.

Exam tips

• Link each feature to the word 'gamete' so the answer stays on the role of meiosis.
• State 'half the number of chromosomes' and use the term 'haploid'.
• Remember the number four for daughter cells and 'genetically different' for variation.