Lab 3 Flashcards
What is a dihybrid cross?
A cross between organisms that vary by two characters.
You get alleles from both parents.
What is a genotype?
Genetic makeup of the organism in terms of alleles present
What is a phenotype?
Observable traits
What does a dihybrid cross begin with?
A dihybrid cross begins with two true breeding strains.
The parent generation is a true-breed.
What do you get when you cross a true breeding strain with itself, what do you get?
You get offspring with the same phenotype as the parent.
True breeding strains are either?
Homozygous dominant or recessive.
F2 generation ratio when you self an (f1) heterozygous dihybrid?
9/16: Homozygous dominant.
3/16: Heterozygous
3/16:Heterozygous.
1/16: Homozygoes recessive.
4 phenotypes occur.
What is meiosis?
Cell division in sexually reproducing organisms that reduces the number of chromosomes in gametes.
What allows for more variety in chromosomes?
Independent assortment.
What is independent assortment?
During gamete formation, tetrads line up independently of other tetrads.
