Chapter 16 Flashcards
Define unlinked
Genes on non homologous chromosomes that behave independently in their movements into gametes. Do not affect eachother
How are non linked genes expressed
As ; Bb
With a semi colon
What’s the expected phenotypic ration result from a di hybrid cross of two heterozygotes
9 (4 genotypes)
3 (2 genotypes)
3 (2 genotypes)
1 (1 genotype)
9:3:3:1
Do a di hybrid test cross
Look somewhere
What is a di hybrid test cross used for
To identify the linkage realationship between two genes.
One parent is homozygous recessive(ppqq) and the other is heterozygous(PpQq)
What’s the name of the genotype that’s produced identical to the parents
Parental genotype
What’s the name of the genotype that’s produced that’s different from the parents
Recombinant genotype
If genes are unlinked the ratio will be
1:1:1:1
What are linked genes
Genes that are located close together on the chromosome
What does crossing of do
Increases variation
The closer two linked genes are….
The less the chance that crossing over will separate the parental arrangement of alleles.
What is genetic screening
Used to identify specific (often harmful) genes in embryos. Usually done with a person with a family that has a history for a disease.
