MC	Biology	Standard: 04
Objective: 02. Predict and interpret patterns of inheritance in sexually reproducing organisms.
ILO:

How did people respond to Mendel's ideas on inherited traits?

a. immediately accepted by his peers

b. thought to be far ahead of their time

c. not recognized for more than thirty years

d. found to be out of date even then

e. lost and have never been found

Correct Answer: c

MC	Biology	Standard: 04
Objective: 02. Predict and interpret patterns of inheritance in sexually reproducing organisms.
ILO:

The following pedigree chart shows sex-linked inheritance of color blindness for three generations of a family. Review the pedigree chart. Answer the following questions.

1. What is the genotype of Individual #2 in the first generation?

a. X^CX^c

b. X^CX^C

c. X^CY

d. X^cY

2. What type of trait is color-blindness?

a. Dominant

b. Recessive

c. Codominant

d. Multiple Allele

3. According to the pedigree, who is passing on the genes for color-blindness to Individual #4 of the third generation?

a. Individual #3 of the second generation

b. Individual #4 of the second generation

c. Individuals #3 and #4 of the second generation.

d. Individuals #2 and #3 of the second generation.

4. What is genotype of Individual #4 of the second generation?

a. X^CX^c

b. X^CX^C

c. X^CY

d. X^cY

5. What is the genotype of Individual #2 if the third generation?

a. X^CX^c

b. X^CX^C

c. X^CY

d. X^cY

Correct Answers:

1. a

2. b

3. c

4. a

5. d

MC	Biology	Standard: 04
Objective: 02. Predict and interpret patterns of inheritance in sexually reproducing organisms.
ILO:

What is the probability of two heterozygous parents having a child that is homozygous dominant?

a. 1/8

b. 1/4

c. 1/2

d. 1

e. 2

Correct Answer: b

MC	Biology	Standard: 04
Objective: 02. Predict and interpret patterns of inheritance in sexually reproducing organisms.
ILO:

In a cross involving simple dominance, using B = Black hair and b = blonde hair, if you have a male who is heterozygous crossed with a homozygous dominant female, what percent of their offspring will have blonde hair?

a. 0%

b. 25%

c. 50%

d. 75%

e. 100%

Correct Answer: c

MC	Biology	Standard: 04
Objective: 02. Predict and interpret patterns of inheritance in sexually reproducing organisms.
ILO:

Using T = tall and t = short. If a heterozygous male crosses with a heterozygous female, what is the genotype ratio?

a. 2:2

b. 4:0

c. 3:1

d. 3:3

e. 1:2:1

Correct Answer: e

MC	Biology	Standard: 04
Objective: 02. Predict and interpret patterns of inheritance in sexually reproducing organisms.
ILO:

Mary has natural blonde hair. Both of her parents have natural brown hair. In humans, brown is dominant and blonde is recessive. Chose the genotype that best describes MaryÕs parents.

a. Bb and Bb

b. BB and Bb

c. BB and BB

d. bb and BB

e. bb and bb

Correct Answer: a

MC	Biology	Standard: 04
Objective: 02. Predict and interpret patterns of inheritance in sexually reproducing organisms.
ILO:

Which of the following is an inference?

a. Selective breeding produces organisms with resistance to specific diseases.

b. Selective breeding creates larger fruits, such as strawberries.

c. Milk production in cows can be increased by selective breeding.

d. Humans who eat hybrid cows will become immune to infections.

Correct Answer: d

MC	Biology	Standard: 04
Objective: 02. Predict and interpret patterns of inheritance in sexually reproducing organisms.
ILO:

The creeper syndrome in chickens is due to a recessive condition that results in the severe shortening of the legs. A chicken producer mates a rooster (Cc) to hens that are carrying the creeper gene also (Cc). What are the expected genotypic and phenotypic ratios of the offspring of each hen?

a. 2 normal chickens (CC), 2 creepers (cc)

b. 2 normal chickens (CC), 1 creeper (cc), 1 carrier (Cc)

c. 3 normal chickens (CC), 1 carrier (Cc)

d. 1 normal chicken (CC), 1 creeper (cc), 2 carriers (Cc)

e. 1 normal chicken (CC), 2 creepers (cc), 1 carrier (Cc)

Correct Answer: d

MC	Biology	Standard: 04
Objective: 02. Predict and interpret patterns of inheritance in sexually reproducing organisms.
ILO:

Which breeding system reduces genetic variation in a population?

a. Crossbreeding

b. Linebreeding

c. Inbreeding

d. Outcrossing

e. Outbreeding

Correct answer: c

MC	Biology	Standard: 04
Objective: 02. Predict and interpret patterns of inheritance in sexually reproducing organisms.
ILO:

A family with a history of breast cancer has been given an opportunity to have all family members tested for the BRCA2 breast cancer gene. The presence of even a single copy of the detrimental gene indicates a significantly higher risk for a carrier; two copies elevates the risk even higher. One branch of the family (1) wishes to be tested immediately but another (family 2) wishes not to be tested.

What would a genetic counselor say to the families?

a. There is no chance these families will be affected by the disorder, therefore testing is not necessary.

b. There is no chance these families will be affect3ed by the disorder, but testing will be required by the counselor.

c. There is a chance that one or more family members will be affected, so testing is required.

d. There is a chance that family members will be affected, but testing will be up to the individuals.

Correct Answer: d

I	Biology	Standard: 04
Objective: 02. Predict and interpret patterns of inheritance in sexually reproducing organisms.
ILO:

Assuming the data relating to height of pea plant in MendelÕs experiments, use the Punnett Square to answer the two questions below.

A heterozygous tall plant is crossed with a purebred (homozygous) short plant. Let (T) represent the gene that controls the appearance of the tall plants

	T	t
t
t

1. Use the chart to determine the number of each type.

Number of Plants	Type
	Tall Heterozygous
	Tall Purebreds
	Short Heterozygous
	Short Purebreds

2. What type of parent plants would you need in order to have all tall heterozygous plants?

Rubric:

1. 2 pts for 2 tall heterozygous

2 pts for 2 short purebred (homozygous)

2. 2 pts for purebred tall and purebred short

1 pt for one of the answers either purebred tall or purebred short

I	Biology	Standard: 04
Objective: 02. Predict and interpret patterns of inheritance in sexually reproducing organisms.
ILO:

Genetic History Lesson

You are a genetic counselor and have prepared a family history for a woman (Jane) who has just given birth to a son who has hemophilia. Hemophilia is a sex-linked trait that shows up in 50% of the sons born to mothers who are carriers for the disease. Jane has four sisters and a brother; none of them have hemophilia, neither do her parents. It is not known whether or not any others in the family are carriers for the disease. With the information provided and your knowledge of heredity answer the following questions.

1. Assuming that no fresh mutations have occurred in this family, draw a pedigree showing the history of hemophilia in the family. Indicate all possible gene combinations.

2. Use a Punnett square to show possible offspring that could occur if Jane's husband is a normal male. (Remember: this is a sex-linked trait).

3. As you were counseling with Jane, about the implications of her being a carrier for hemophilia, she refuses to tell the names of her sisters who are all of child bearing ages. She warns you not to upset her family by trying to make contacts. You are concerned about this refusal. Why?

4. In your opinion should genetic counselors be required to keep the information of those who seek their services private? Why or why not?

Correct Answers:

1 & 2.

3. Since Jane's brother doesn't have the disease, he must not have inherited the gene from his mother, but all of Jane's sisters could also be carriers for hemophilia just like Jane. Because the sisters are all of childbearing age, if any sister is a carrier each of her sons would have a 50% chance of inheriting hemophilia. As a counselor you would feel it important to share this information with the sisters so that they could consider whether they should be tested, and make family planning decisions based on the outcome of the tests.

4. This is an opinion question, look for logical explanations backed up with evidence.

I	Biology	Standard: 04
Objective: 02. Predict and interpret patterns of inheritance in sexually reproducing organisms.
ILO:

Neighborhood Health Fair

The Johnson Family went to a neighborhood health fair. They were impressed with the many screenings, demonstrations, and exhibits related to health promotion and disease prevention. They went to a booth where the staff was doing blood screening. One of the diseases that was screened for was sickle-cell anemia. Sickle-cell anemia is a genetic disorder of red blood cells that occurs when someone inherits two recessive genes for the disease, one from each parent. A person who inherits only one recessive gene will not usually get the disease but is said to have the sickle- cell trait.

The disorder causes the red blood cells to become distorted. They then cannot flow easily through the tiny capillaries, and they create an obstruction. This decreases the blood supply to the vital organs, which in turn may be damaged.

When the Johnson family got their tests back, they made a pedigree showing the trait in their family. Use the pedigree and your knowledge of inheritance to answer the following questions.

1. Look at the parents (#1 and #2) they both have the genotype Aa. This means they

a. have sickle-cell anemia

b. have a gene mutation

c. are carriers of the sickle-cell trait

d. will eventually develop sickle-cell anemia

2. Person #7 in the pedigree, female genotype aa

a. has sickle-cell anemia

b. is a carrier for sickle-cell anemia

c. will show no symptoms of sickle-cell anemia

d. will have blood that will not clot

3. Person #5 , a male with genotype Aa

a. probably will not be able to participate in active sports

b. possibly will die at an early age from sickle-cell anemia

c. could develop sickle-cell anemia later in life

d. will not have sickle-cell anemia

4. If person # 5 were to marry a person who was normal and not a carrier for sickle-cell trait

a. one half of their children would be carriers for sickle cell anemia

b. one half of their children will develop sickle-cell anemia

c. all of their children would be carriers for sickle-cell anemia

d. all of their children would develop sickle-cell anemia

5. Not long after child #5 visited the health fair where he had this screening, he decided to try out for his high school basketball team. His coach reviewed his medical history and found that he had the sickle-cell trait. Even though he seemed to be in excellent physical condition his coach released him from the team fearing that he would not be able to perform to his peak performance at critical times. The coach recommended that #5 try out for a less strenuous sport. How should #5 reply?

6. Some people believe that all citizens should submit to blood tests to screen for genetic disorders. They argue that the program would benefit public health and allow them to plan their family more rationally. What problems might screening of this type cause?

Correct Answers:

1. c

2. a

3. d

4. d

5. He should tell his coach that having sickle-cell trait merely means that he is a carrier for sickle-cell anemia and that he would not get the disease. There would be no reason he should not be able to perform at his peak performance in any game, as his physical condition would not be affected in any way by being a carrier.

6. Besides being costly, it may lead to discrimination. Health insurance carriers for example may not want to pay for medical costs of people, who, based on their genetic screening, are at risk for certain disorders.

I	Biology	Standard: 04
Objective: 02. Predict and interpret patterns of inheritance in sexually reproducing organisms.
ILO:

In the pedigree above, the shaded individuals are homozygous recessive.

1. What is the genotype of individual B?

a. heterozygous

b. homozygous recessive

c. homozygous dominant

d. can not tell from the diagram

2. What is the genotype of individual E?

a. heterozygous

b. homozygous recessive

c. homozygous dominant

d. can not tell from the diagram

3. If individual E married an individual who is homozygous recessive, what is the probability that their first child will be homozygous recessive?

a. 1/8

b. 1/4

c. 1/2

d. 1

Correct Answers:

1. a

2. a

3. c

I	Biology	Standard: 04
Objective: 02. Predict and interpret patterns of inheritance in sexually reproducing organisms.
ILO:

R