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Bio Vocab
Term | Definition |
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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 the 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 | A 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 two individuals that mate in a genetic cross. |
F1 generation | The 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 the F1 generation. |
Dominant | Describes the allele that is fully expressed when carried by only one pair of homologous chromosomes. |
Recessive | Describes a trait or an allele that is expressed only when two recessive alleles for the same characteristic are inherited. |
Law of Segregation | Mende's law that states that the 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. |
Genotype | The entire genetic makeup of an organism; also the combination of genes for one or more specific traits. |
Phenotype | An organism's appearance or other detectable characteristic that results from the organism's genotype and the environment. |
Homozygous | Describes an individual that has identical alleles for a trait on both homologous chromosomes. |
Heterozygous | Describes an individual that has two different alleles for a trait. |
Probability | The likelihood that a possible future event will occur in any given instance of the event; the mathematical ratio of the number of times one outcome of any event is likely to occur to the number of possible outcomes of the event. |
Monohybrid Cross | A cross between individuals that involves one pair of contrasting traits. |
Punnett Square | A graphic used to predict the results of a genetic cross. |
Genotypic Ratio | The ratio of the genotypes that appear in offspring. |
Phenotypic Ratio | The ratio of phenotypes produced by a cross. |
Testcross | The crossing of an individual of unknown genotype with a homozygous recessive individual to determine the unknown genotype. |
Complete Dominance | A relationship in which one allele is completely dominant over another. |
Incomplete Dominance | A condition in which a trait in an individual is intermediate between the phenotype of the individual's two parents because the dominant allele is unable to express itself fully. |
Codominance | A condition in which both alleles for a gene are fully expressed. |
Dihybrid Cross | A cross between individuals that have different alleles for the same gene. |