GENETICS Flashcards
define phenotype
the physical appearance of a trait
define gene
the unit of inheritance
define allele
the different forms of the gene
define genotype
the genetic makeup of an individual
define homozygous
same two alleles for a gene
define heterozygous
different alleles for the same gene
what does independent segregation mean
an individuals gametes will contain only one of the two alleles present in other cells (randomly selected)
what does independent assortment mean
chance determines which factor for a particular trait is inherited and this is not influenced by other genes
what does dominance mean
one allele will be dominant of the other. when both alleles are present the dominant allele is observed in the phenotype
what is cross breeding
it is when one homozygous dominant and one homozygous recessive organisms are crossed to give four heterozygous offspring
what is a monohybrid cross
cross two heterozygous organisms to give the offspring genotypic ratio of 1:2:1 but the phenotypic ratio is 3:1
what is a dihybrid cross
when you cross a homozygous dominant (AABB) and a homozygous recessive (aabb).
what are the gametes in a dihybrid cross
AB Ab aB ab
whats the genotypic ration
9:3:3:1
