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Advanced Higher
Unit 2 - Meiosis
| Question | Answer |
|---|---|
| State the four features of homologous chromosomes | Same size, same gene loci, same banding pattern, same centromere location |
| What is meiosis? | 2 cycles of nuclear division called meiosis I and meiosis II to produce haploid gametes that increase genetic variation during sexual reproduction. |
| Where is meiosis located? = | Gamete mother cells and sex organs |
| What is produced at the end of Meiosis I | 2 haploid cells that are genetically different |
| What is produced at the end of Meiosis II | 4 haploid cells that are genetically different |
| Explain the term random assortment. | Separation of parental chromosomes irrespective of their maternal or paternal origin |
| Where does crossing over take place? | Chiasma(ta) |
| Explain the term crossing over | Random crossing over at chiasmata resulting in exchange of DNA between homologous pairs and recombination of alleles of linked genes. |
| In recombination, which genes will have a higher recombination frequency? | Genes that are further apart |
| State the two ways organisms can use meiosis to produce gametes. | 1.gametes are formed directly from the cells produced by meiosis. 2. mitosis may occur after meiosis to form a haploid organism; gametes form later by differentiation |
| Which stage of meiosis includes homologous chromsomes | Meiosis I |
| Where does random assortment and crossing over occur? | When homologous chromosomes pair and line up along the metaphase plate |