Mendelian Genetics Flashcards
gene
segment of DNA that controls a particular characteristic or trait
allele
different forms/variations of a gene
genotype
genetic makeup of an organism, an organism’s combination alleles
phenotype
the physical expression of an organism’s genes - what you can see
homozygous
2 alleles are the same
heterozygous
2 alleles are different
dominant
an allele that masks a recessive allele;
an allele that expresses itself even in the presence of another allele
recessive
gene is not allowed to express itself when it is covered up or masked by the presence of another gene
hybrid
Mendel’s term for heterozygous
purebred
Mendel’s term for homozygous
Law/Principle of Dominance
in every pair of contrasting traits, one is dominant one is recessive
when two or more alleles exist, some are dominant some are recessive
basically, some alleles are dominant and some are recessive
Law of Segregation
alleles for a gene segregate independently from one another during the formation of gametes
Genotypic Ratios
DD:Dr:rr
Phenotypic Ratio
dominant:recessive
Phenotypic Ratio in a two-factor cross
DD:DR:RD:RR
