README.md

genetics-problems

Python Scripts for Generating Genetics Homework/Quiz problems

Table of Contents

• genetics-problems
• Table of Contents
  • Blood Types
    • blood_type_offspring.py
    • blood_type_mother.py
    • hla_genotype.py
  • Gametes
    • gametes_unique.py
  • Epistasis
    • epistasis_test_cross.py
    • epistasis_inverse_test_cross.py
  • X-linked disorders
    • poisson_flies.py
  • Chi-Squared Analysis
    • Table of Chi-Squared (χ²) Critical Values
    • chi_square_errors.py

Created by gh-md-toc

Blood Types

blood_type_agglutination_test.py

• Download list of questions in blackboard upload format

What will the results of a blood test look like for a person with O- blood type?

• A.
• B.

blood_type_offspring.py

• Download list of questions in blackboard upload format

1. For the ABO blood group in humans, the i^A and i^B alleles are codominant and the i allele is recessive. If a female ♀ with type A blood marries a male ♂ with type O blood, which of the following blood types could their children possibly have? Check all that apply.

• A. Type O blood
• B. Type A blood
• C. Type B blood
• D. Type AB blood

blood_type_mother.py

• Download list of questions in blackboard upload format

2. For the ABO blood group in humans, the i^A and i^B alleles are codominant and the i allele is recessive. A father ♂ who has blood type AB has a son ♂ who has blood type A, which of the following blood types could the mother ♀ possibly have? Check all that apply.

• A. Type O blood
• B. Type A blood
• C. Type B blood
• D. Type AB blood
• E. None of the above are possible

hla_genotype.py

• Download list of 2 gene questions in blackboard upload format
• Download list of 3 gene questions in blackboard upload format

3. A mother has a HLA genotype of A2,B5,C6 on one chromosome and A1,B1,C3 on the other. The father has a HLA genotype of A7,B9,C2 on one chromosome and A8,B3,C5 on the other. Which one of the following is a possible genotype for one of their offspring?

• A. A2,A8,B1,B9,C2,C3
• B. A1,A2,B1,B5,C3,C6
• C. A2,A7,B5,B9,C2,C6
• D. A7,A8,B3,B9,C2,C5
• E. A1,A7,B1,B3,C5,C6

Gametes

gametes_unique.py

• Download list of questions in blackboard upload format

1. How many unique gametes could be produced through independent assortment by an individual with the genotype AA Bb cc dd Ee Ff Gg ?

• A. 2² = 4
• B. 2³ = 8
• C. 2⁴ = 16
• D. 2⁵ = 32
• E. 2⁶ = 64

Epistasis

epistasis_test_cross.py

• Download list of questions in blackboard upload format

1. In a specific cross, F₂ progeny exhibit a modified dihybrid ratio of 15:1 (instead of 9:3:3:1 ). What phenotypic ratio would be expected from a test-cross with an individual from the F₁ progeny?

• A. 1:4
• B. 2:2 or 1:1
• C. 4:1
• D. 3:1
• E. 2:1
• F. 1:3

epistasis_inverse_test_cross.py

• Download list of questions in blackboard upload format

2. An F₁ heterozygote individual from dihybrid cross is used for a test-cross. The progeny from the test-cross exhibited a modified ratio of 3:1 (instead of 1:1:1:1). What phenotypic ratio would be expected in the F₂ progeny if the dihybrid cross is continued?

• A. 13:3
• B. 12:4
• C. 11:5
• D. 10:6
• E. 9:7

X-linked disorders

poisson_flies.py

• Download list of questions in blackboard upload format

1. The white-eyed phenotype is an X-linked recessive disorder in fruit flies. The red allele, +, is dominant to the white allele, w. The offspring of size 400 from the mating of a single female and a single male are shown in the table below:

phenotype	female ♀	male ♂
red-eyed (wildtype)	0	0
white-eyed (mutant)	185	215

What are the genotypes of the parents in this cross?

• A. homozygous wildtype female (++) and male of unknown genotype
• B. heterozygous female (+w) and wildtype male (+–)
• C. heterozygous female (+w) and mutant male (w–)
• D. homozygous mutant female (ww) and wildtype male (+–)
• E. homozygous mutant female (ww) and mutant male (w–)

Chi-Squared Analysis

Table of Chi-Squared (χ²) Critical Values

Table of Chi-Squared (χ2) Critical Values
Degrees of Freedom	Probability
	0.95	0.90	0.75	0.50	0.25	0.10	0.05	0.01
1	0.00	0.02	0.10	0.45	1.32	2.71	3.84	6.63
2	0.10	0.21	0.58	1.39	2.77	4.61	5.99	9.21
3	0.35	0.58	1.21	2.37	4.11	6.25	7.81	11.34
4	0.71	1.06	1.92	3.36	5.39	7.78	9.49	13.28

chi_square_errors.py

• Download list of questions in blackboard upload format

1. The final result gives the chi-squared (χ²) test value of 3.58 with 3 degrees of freedom. Using the Table of χ² Critical Values and a level of significance α=0.50, we get a critical value of 2.37. Since the chi-squared (χ²) test value of 3.58 is greater than the critical value of 2.37, the null hypothesis was rejected.

Phenotype	Expected	Observed	Calculation	Statistic
Yellow Round (Y–R–)	90	94	(94-90)2⁄ 90	0.178
Yellow Wrinkled (Y–rr)	30	21	(21-30)2⁄ 30	2.700
Green Round (yyR–)	30	33	(33-30)2⁄ 30	0.300
Green Wrinkled (yyrr)	10	12	(12-10)2⁄ 10	0.400
(sum) χ2 =				3.578

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Your lab partner has done a chi-squared (χ²) test for your lab data (above), for the F₂ generation in a standard dihybid cross. They wanted to know if the results confirm the expected phenotype ratios, but as usual they did something wrong. Where did they do wrong?

• A. the expected progeny for the null hypothesis is incorrect
• B. the degrees of freedom is wrong
• C. the numbers in the calculation have to be squared
• D. the wrong numbers in the calculation were used for division
• E. the wrong rejection criteria was used

Progeny

probabiliy_of_progeny.py

• Download list of questions in blackboard upload format

A women has nine (9) children, what is the probability that she has exactly five (5) boys and four (4) girls?