Meiosis and Genetic Diversity Flashcards
What is the purpose of meiosis?
To produce haploid gametes for sexual reproduction.
What are the two stages of meiosis?
Meiosis I (reductional division) and Meiosis II (equational division).
What occurs during prophase I?
Homologous chromosomes pair up and exchange genetic material (crossing over).
What is independent assortment?
Random alignment of homologous chromosomes during metaphase I.
What happens in anaphase I?
Homologous chromosomes are separated, while sister chromatids stay together.
How does meiosis create genetic variation?
Through crossing over, independent assortment, and random fertilization.
What is the result of meiosis II?
Four genetically unique haploid gametes.
Define synapsis.
The pairing of homologous chromosomes during prophase I.
What is a chiasma?
The point where crossing over occurs between homologous chromosomes.
What ensures gamete diversity in meiosis?
Random segregation of homologs and crossing over.
How does recombination during meiosis affect SNP inheritance?
Recombination shuffles SNPs, with closely linked SNPs less likely to separate.
What happens to SNP patterns under strong selection with low recombination?
SNPs near a beneficial mutation show reduced diversity, forming long conserved haplotypes.
What would SNP data look like without recombination?
SNPs would remain fixed in large blocks with little variation.
How does meiosis provide evidence for selection?
Recombination during meiosis creates patterns of SNP inheritance, with linked SNPs near beneficial alleles showing reduced diversity.
How does Tishkoff et al. (2007) connect meiosis to lactase persistence?
The study used recombination patterns to track the origin and spread of lactase persistence alleles.
