In a species of flowering plant, male gametes P and Q are carried in pollen grains and egg cells R and S are held in ovules. Each gamete contains 11 chromosomes.
M and m are different alleles of one gene. N and n are different alleles of a second gene. The table shows the alleles carried by four gametes produced by meiosis.
| Gamete | Allele of the first gene | Allele of the second gene |
|---|---|---|
| P | M | n |
| Q | m | N |
| R | m | n |
| S | M | N |
Gamete P fuses with gamete R to form zygote 1. Gamete Q fuses with gamete S to form zygote 2.
Compare the chromosome number and the combinations of alleles in zygote 1 and zygote 2.
92 exam-style questions on Edexcel GCSE Biology 3.1 Reproduction and meiosis, covering 3.1.1 Advantages and disadvantages of reproduction and 3.1.2 Role of meiotic cell division. Each one has a worked solution and a mark scheme showing where the marks go.