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Biology Chapter 9
Biology Chapter 9 Section 1
Term | Definition |
---|---|
genetics | the science of heredity and of the mechanisms by which traits are passed from parents to offspring |
heredity | the passing of genetic traits from parent to offspring |
trait | a genetically determined characteristic |
pollination | the transfer of pollen from male reproductive structures (the anthers) to the tip of a female reproductive structure (the pistil) of a flower in angiosperms or to the ovule in gymnosperms |
self-pollination | the transfer of pollen grains from an anther to the stigma of the same flower or to the stigma of another flower on the same plant |
cross-pollination | the reproductive process in which pollen from one plant is transferred to the stigma of another plant |
true-breeding | describes organisms or genotypes that are homozygous for a specific trait and thus always produce offspring that have the same phenotype for that trait |
P generation | parental generation, the first 2 individuals that mate in a genetic cross |
F1 generation | first generation of offspring obtained from an experimental cross of two organisms |
F2 generation | the second generation of offspring, obtained from an experimental cross of two organisms;the offspring of F1 generation |
dominant | describes the allele that is fully expressed when carried by only one of a pair of homologous chromosomes |
recessive | describes a trait or allele that is expressed only when two recessive alleles for the same characteristic are inherited |
law of segregation | Mende's law that states that pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete |
law of independent assortment | the law that states that genes separate independently of one another in meiosis |
molecular genetics | the study of the structure of nucleic acids and the function and regulation of genes |
allele | one of the alternative forms of a gene that governs a characteristic such as hair color |