Biology Review: Genetics

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The study of genes and their heredity
Segments of DNA that are information/ instructions for one trait
The way genes are passed down (generations)
Blending Theory of Inheritance
The main theory of earlier genetics; states that an offspring is a mix of parents’ traits
Gregor Mendel (1800s)
Called the Father of Modern Genetics, a monk and gardener, who saw variety in plants and wanted to test this; he tested pea plants, because they only have two varieties of a trait, by cross- pollinating them; his results contradicted the blending theory
Self- pollination/ Cross- pollination
Sexual reproduction where the pollen travels to another part of the plant to fertilize/ Pollen goes to another plant to fertlize
Pure- bred/ Hybrid
A copy offspring created by self- pollination/ A combining offspring created by cross- pollination
Different variations of the same gene trait; found in homologous chromosomes, and offspring always recive two for each trait (1 from each parent)
Dominant allele (T)/ Recessive allele (t)
Needs only one allele to be able to show in offspring/ Can be hidden by dominant allele; two are needed to show in offspring
Genotype/ Phenotype
The combination of alleles an offspring can have for a trait/ The characteristics an offspring can have due to the genotype
Homozygous/ Heterozygous
A way to describe a genotype where where two alleles are the same/ A way to describe a genotype where the two alleles are different
The chances of something happening; in genetics, the possibility of an offspring recieveing a certain trait due to the alleles; every event, the chances are the same
Punnett square
A diagram used to determine probability in genetics
Seperation of alleles in homologous chromosomes during meiosis
Monohybrid cross/ Dihybrid cross
A crossing of parents that creates a hybrid; for 1 trait/ Same, for 2 traits
Test cross
The way to test some organisms for their genotype, by crossing them with a homologous recessive (tt) organism
Independent assortment
The various amount of alleles that a parent can pass on to its offspring
FOIL (First, Inner, Outer, Last)
A method used to translate parent genotypes in dihybrid crosses into genotypes for the Punnett square
Categories: Genetics