Year 11 Genetics - Harder Keywords

2. reproduction A form of producing offspring involving the fertilization of two gametes from two parents, producing variation in the offspring.
6. breeding A process for breeding a specific required trait.
8. pressure Environmental factors that that reduce or increase the reproductive success of individuals with a particular phenotype over another.
9. A group of individuals that can breed to produce fertile offspring.
11. assortment The random arrangement of homologous chromosomes when lining up and separating during meiosis.
12. A body cell.
14. allele The allele that is always expressed (shows up as a trait) if it is present in the genotype.
16. drift A change in allele frequency within a population due to a random event.
18. The change in the gene pool within a population over many generations.
20. A permanent change in the base sequence of DNA that causes variation.
21. A type of cell division which produces identical body cells for growth and repair, or to produce clones through asexual reproduction.

1. pool The set of all the alleles present in a population.
3. An alternative version of a gene (with a slightly different order of base pairs).
4. effect When a population's size is dramatically reduced, leading to a loss of genetic diversity and altering allele frequencies in the surviving individuals.
5. The fusing (joining) of a male and female gamete to form a zygote.
7. A fertilized egg, formed by the fusion of male and female gametes
10. over When homologous chromosomes exchange alleles during meiosis, which increases genetic variation.
13. flow The transfer of alleles from one population to another, usually by migration.
15. A type of cell division which produces egg and sperm cells (gametes) with half the number of chromosomes of the parent cell.
17. selection The process by which beneficial phenotypes in a population tend to be preserved while unfavourable phenotypes tend to be lost.
19. bottleneck An event that drastically reduces the size of a population.