For Questions 1-7; answer with the phenotypic and genotypic ratios for each cross.
Question 8; review co-dominance in your book and lecture notes.
Genetics-Heredity Study
Concepts/Words to know: – Gregor Mendel – P, Fl, F2 Generations – Codominant – Incomplete Dominance – Heterozygous – Allele
Name
Homozygous Dominant and recessive Autosomal X-linked Blood Types and transfusions Pedigrees Punnett Square
1) A green pea plant (Gg) is crossed with a yellow pea plant (gg).
Date Section
– Pea Plants – Genetic disorders – X-linked recessive – Carrier – Hemophilia
2) A tall plant (TT) is crossed with a tall plant (Tt).
3) A tall plant (Tt) is crossed with a short plant (tt).
4) A red flower (Rr) is crossed with a white flower (rr).
5) A white flower (rr) is crossed with a white flower (rr).
6. A homozygous dominant brown mouse is crossed with a heterozygous brown mouse (tan is the recessive color).
7. Two heterozygous white (brown fur is recessive) rabbits are crossed.
8. In some chickens, the gene for feather color is controlled by codiminance. The heterozygous phenotype is known as erminette.
a. What is the genotype for black chickens?
b. What is the genotype for white chickens?
c. What is the genotype for erminette chickens?
Questions 9 and 10 below: Create a dihybrid Punnett square with Pea. Once you have the parental genotypes, select the gametes using 1-3; 1-4; 2-3; 2-4 method.
Then create the 16 genotypes possible; summarize with the ending ratio to the right of the 16 squares. R=round, r-wrinkled, T=tall, t=short, Y= yellow peas, y= green peas, P=purple flowers, p=white flowers.
9. Make the following Punnett square. RrYY x rrYy 16 box square.
What are the phenotypic and genotypic ratios of the offspring?
10. Extra Credit: Worth an extra 10 points!!! Make the following Punnett square. RrYYTT x rrYytt 8*8 or 64 squares. Use a blank sheet as needed.
What is the phenotypic ratio of the offspring?
Your gametes: 1-3-5; 1-3-6; 1-4-5; 1-4-6; 2-3-5; 2-3-6; 2-4-5; 2-4-6;
