6F Genetics
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Transcript of 6F Genetics
6F Genetics
Gregor Mendel
Genetics
• the study of heredity and the variation of inherited characteristics.
Gene
• a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.
Trait
• Physical characteristics or attributes of an organism that are expressed by genes such as eye color, hair color, leaf shape, etc…
Allele
• one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.
Homozygous
• refers to having two of the same alleles for a single trait.
• Ex: AA or aa
• Both alleles are either dominant or recessive
Heterozygous
• refers to having two different alleles for a single trait.
• Ex: Aa
• One allele is dominant while the other allele is recessive
Dominant Allele
• an allele that produces the same phenotype whether its paired allele is identical or different
• Ex: A (with a capital letter)
Recessive Allele
• an allele that produces its characteristic phenotype only when its paired allele is identical.
• Ex: a (with a lower case letter)
Genotype
• the genetic makeup of an organism or group of organisms with reference to a single trait, set of traits, or an entire complex of traits.
• Ex: AA, Aa or aa
Phenotype
• the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.
• Ex: brown eye color, blond hair color
Monohybrid Cross
• a genetic cross using a single trait with two alleles.
• Ex: AA x aa
Dihybrid Cross
• In a genetic cross, a hybridization using 2 traits with 2 alleles each
• Ex: AABB x aabb
Dihybrid Cross