Fundamentals Of Genetics Ch. 9

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Genetics

Back 1

The field of biology devoted to understanding how characteristics are transmitted from parents to offspring.

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Heredity

Back 2

The passing of genetic traits from parent to offspring.

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Trait

Back 3

A genetically determined variant of a characteristic.

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Pollination

Back 4

The transfer of pollen from the male reproductive structures to the tip of a female reproductive structure of a flower in angiosperms or to the ovule in gymnosperms.

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Self-Pollination

Back 5

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.

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Cross-Pollination

Back 6

a reproductive process in which pollen from one plant is transferred to the stigma of another.

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True-Breeding

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Describes organisms or genotypes that are homozygous for a specific trait and thus always produce offspring that have the same phenotype for that trait.

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P Generation

Back 8

parental generation, or the first two individuals that mate in a genetic cross.

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F1 Generation

Back 9

the first generation of offspring obtained from an experimental cross of two organisms.

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F2 Generation

Back 10

the second generation of offspring, obtained from an experimental cross of 2 organisms; the offspring of the F1 generation.

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dominant

Back 11

describes the allele that is fully expressed when carried by only one of a pair of homologous chromosomes.

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recessive

Back 12

a trait or allele that is expressed only when to recessive alleles for the same characteristic are inherited.

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law of segregation

Back 13

states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete

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law of independent assortment

Back 14

states that the genes separate independently of one another in meiosis.

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molecular genetics

Back 15

the study of the structure of nucleic acids and the function and regulation of genes.

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allele

Back 16

one of the alternative forms of a gene that governs a characteristic, such as hair color.

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genotype

Back 17

the entire genetic makeup of an organism; also the combination of genes for one or more specific traits.

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phenotype

Back 18

an organisms appearance or other detectable characteristic that results from the organisms genotype and the environment.

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homozygous

Back 19

describes an individual that has identical alleles for a trait on both homologous chromosomes

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heterozygous

Back 20

an individual that has 2 different alleles for a trait.

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probability

Back 21

the likelihood that a possible future event will occur in any given instance/event.

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monohybrid cross

Back 22

a cross between individuals that involves one pair of contrasting traits

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punnett square

Back 23

a graphic used to predict the results of a genetic cross.

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genotypic ratio

Back 24

the ratio of the genotypes that appear in offspring

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phenotypic ratio

Back 25

the ratio of phenotypes produced by a cross.

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testcross

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the crossing of an individual of unknown genotype with a homozygous recessive individual to determine the unknown genotype.

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complete dominance

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a relationship in which one allele is completely dominant over another.

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incomplete dominance

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a condition in which a trait in an individual is intermediate between the phenotype of the individuals 2 parents b/c the dominant allele is unable to express itself fully

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codominance

Back 29

a condition in which both alleles for a gene are fully expressed.

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dihybrid cross

Back 30

a cross between individuals that have different alleles for the same gene.