Genetics Flashcards
Alleles
A variation of a gene.
Genotype
A combination of alles (e.g. AA, Aa, aa)
Phenotype
A physical characteristic controlled by a genotype.
AA
Homozygous dominant
Aa
Heterosygous
aa
Homozygous recessive
Dominant
Is shown in phenotype if present
Recessive
Is shown only if homozygous
Incomplete dominance
Blended alleles to produce a third phenotype.
red alleles + white alleles = pink flowers (blended phenotype)
Co-dominance
Both alleles are equally dominant and both traits are shown in phenotypes.
red allele + white allele = parts red + parts white in phenotype
Meiosis
Cell division to produce sex cells (ova and sperm)
autosome
A non-sex chromosome
chromatid
One of two identical DNA strands forming a replicated chromosome and held together by a centromere
Hemizygous dominant
Only one allele
genome
The complete set of genetic information in an organism
Karyotype
An individual’s complete set of chromosomes
Sex-linked inheritance
Traits or disorders are influenced by genes on the X chromosome, as it contains many more genes than the smaller Y chromosome.
Males, who have only a single copy of the X chromosome, are more likely to be affected by a sex-linked disorder than females, who have two copies
Test cross
A test cross involves mating an unknown genotypic individual with a known homozygous recessive
