Different Types of Inheritance. Dihybrid Crosses. Cross that involves two traits Concludes with 16 offspring. Steps for Solve for Dihybrid Cross. Make a key for the two traits that you are crossing Black Hair (B) vs Brown Hair (b) Curly Hair (S) vs Straight Hair (s)
Cross that involves two traits
Concludes with 16 offspring
Set up your punnett square
Inheritance that occurs when one trait is not completely dominant over another
Results in the heterozygous form being blended together
Perform a regular monohybrid punnett square
Only difference is the heterozygous offspring will be mixture of two traits (i.e. if black and white than gray)
Genotype: 4/4 Rr
Phenotype 4/4 Pink
Example: Black fur (B) is dominant over white fur (b) in guinea pigs. Cross a grey guinea pig with a white guinea. What do we get?
Answer: ½ Bb (grey) and ½ bb (white)
Sex Linked Traits
In humans and many other organisms, sex is determined by the X and Y chromosomes.
Sons get their X chromosome from their mothers only.
Fathers must pass their X chromosomes to their daughters.
Daughters can be carriers and pass the trait onto their son.
0%- what about % of being carrier
A woman who is a carrier for hemophilia marries an unaffected male. What is the % chance that their children will be affected?
XH XH XH Xh
XH Y XhY
When two different alleles are present and both are expressed
IA IO IBIO
Results: ½ A blood type or ½ blood type B
Yes he is their son!