Smooth Pod Shape Is Dominant and Constricted Pod Shape Is Recessive

Genetics Practice Problems NAME ______

Begin with the Basics Smooth pod shape is dominant and constricted pod shape is recessive. A pure breeding (homozygous) smooth pod plant is crossed with a pure breeding (homozygous) constricted pod plant. All the offspring are smooth pods.

1. What is the genotype for the parental smooth pods? ______

2. What is the genotype for the parental constricted pods? ______

3. Diagram a Punnett Square for this cross.

4. What is the genotype for the offspring? ______5. Two of the F1 generation (offspring) in the above cross are bred. Diagram a Punnett Square for this cross.

6. What is the genotypic ratio? ______

7. What is the phenotypic ratio? ______

8. What is the probability of producing a smooth pod plant? ______

9. What is the probability of producing a homozygous dominant individual? ______

Cleft chins are dominant to no clefts in humans. A male with a cleft chin marries a female without a cleft chin. They have a son without a cleft chin.

10. What is the child’s genotype? ______

11. What is the mother’s genotype? ______

12. What is the father’s genotype? ______

13. Diagram a Punnett Square for this cross.

14. What is the probability for this couple to have a child with a cleft chin? ______

Let’s Go Jellyfishing! SpongeBob and his pal Patrick love to go jellyfishing at Jellyfish Fields! The fields are home to a special type of green jellyfish known as Goobers and only really great jellyfishermen are lucky enough to catch some on every trip. Many of the jellyfish are yellow (YY) or blue (BB), but some end up green as a result of incomplete dominance. Use this information to help you complete each section below.

1. What would happen if SpongeBob and Patrick crossed two “goobers” or green jellyfish? Complete the Punnett square to help you determine the probability for each color of jellyfish.

(a) Give the possible genotypes and phenotypes for the offspring.

(b) What percentage of the offspring would be yellow? _____%

(c) What percentage would be blue? _____ %

(d) What percentage would be “goobers” (green)? _____ %

2. What would happen if they crossed a yellow jellyfish with a goober? Complete the Punnett square to help you determine the probability for each color of jellyfish. (a) Give the possible genotypes and phenotypes for the offspring.

(b) What percentage of the offspring would be yellow? _____%

(c) What percentage would be blue? _____ %

(d) What percentage would be “goobers” (green)? _____ %

“ I Love What You’ve Done with Your Hair” Hair shape is inherited by incomplete dominance. A gene for straight hair and a gene for curly hair will produce an individual with wavy hair. A man with wavy hair marries a woman with curly hair.

1. What is the man’s genotype? ______

2. What is the woman’s genotype? ______3. Diagram a Punnett Square for this couple.

4. What is the probability of producing a child with straight hair? ______

5. What is the probability of producing a child with wavy hair? ______

6. What is the probability of producing a child with curly hair? ______

8. What is the phenotypic ratio? ______The Blue Chicken Chicken color is a codominant trait. Black Andulasian chickens and white Andulasian chickens form “blue”chickens. (A combination of black and white feathers on the same bird.) Cross: A white and “blue” chicken are crossed.

1. What is the genotype of each parent? ______x ______

5. What is the phenotypic ratio? ______

A Man and a Woman A man with blood type B marries a woman with blood type A. they have a child with blood type O. 1. Diagram a Punnett Square for this couple.

3. What is the woman’s genotype? ______

4. What is the probability for this couple to have a child with blood type AB? ______

5. What is the genotypic ratio for the offspring? ______

A type A woman whose father was type B marries a type B man whose mother was type A. 1. Diagram a Punnett Square for this couple.

3. What is the woman’s genotype? ______

4. What is the probability for this couple to have a child with blood type AB? ______

5. What is the genotypic ratio for the offspring? ______

A couple has a child with type A blood. If one parent is type O, what are the possible genotypes of the other parent?

Parent Possible Genotypes: ______

The Oompahs Oompahs can have red, blue or blured hair. Blured hair results from the heterozygous condition. Make a "key" showing the genotypes and phenotypes for hair color. Is this an example of codominance or incomplete dominance?

1. Orville Oompah has blured hair and is married to Opal Oompah who brags that she has the bluest hair in the valley.

What is the parental genotypes? ______x ______

How many of Opal's children will be able to brag about their blue hair also? ______

What is the phenotypic ratio? ______

2. One of Opal's children is born with shocking red hair.

Is Orville the father of this child? ______(Show your work)

But wait, Opal swears she has been faithful and claims that the hospital goofed and got her baby mixed with another. Is this a plausible explanation. Show the square to prove your answer.

Dimples and Freckles Dimples are dominant to no dimples and freckles are dominant to no freckles in humans.

Diagram a Punnett Square for an individual that is heterozygous for both traits and for an individual that does not have dimples or freckles.

Parent Genotypes: ______

35. What is the phenotypic ratio for this cross? ______