Review the following websites before attempting this assignment:
http://sctritonscience.com/Wilson/biology_punnett_squares.htm
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Assignment4 – Heredity
Name
:
Directions: Complete the Punnett Squares below and answer all associated questions (write legibly). Be sure to include the proper terminology to describe the alleles and the ratios of the genotypes and phenotypes of the characteristics indicated for each item.
Dominate-Recessive Inheritance
In humans, the gene for dimpled cheeks (D) is dominant over its allele for smooth cheeks (d). Complete the Punnett square given the parental cross (DD x dd). Complete the associated Punnett square information.
Genotypic ratio: ___________________________________
Phenotypic ratio: __________________________________
How many off-springs are heterozygous? ________
How many off-springs are homozygous dominate? ________
How many off-springs are homozygous recessive? ________
Could they have a child who has dimpled cheeks? ________
Which number(s)? ________
Dominate-Recessive Inheritance
A homozygous mother with small ears (e) marries a heterozygous man with large ears (E). Complete the Punnett square showing the off-spring possibilities. Complete the associated Punnett square information.
How many off-springs are heterozygous? ________
How many off-springs are homozygous dominate? ________
How many off-springs are homozygous recessive? ________
Will they have a child with small ears? ________
Which number(s)? ________
Multiple-Allele Inheritance
Three babies were born in a hospital on the same night, and their blood groups were later found to be O, B, and AB. Complete the Punnett square to cross parents AB x O (simply using the ABO system) to determine the blood type possibilities their off-springs would have. Use the Punnett square information to determine which baby (A, B, AB, or O) belong to them.
How many off-springs are blood type A? ________
How many off-springs are blood type B? ________
How many off-springs are blood type AB? ________
How many off-springs are blood type O? ________
Baby _________ belongs to the AB and O parents.
Sex-Linked Inheretance
Cross the parents (XBY x XBXb). The father is normal and the mother carries the color blind trait. The allele for color blind is b and normal is B. Complete the Punnett square showing the possible off-springs from this couple. Complete the associated Punnett square information.
Could they have a child who is color blind? ________
Which number(s)? ________