Transcript 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