Unit 5: Heredity
Biology · Unit 5 · Paper 2

Heredity unit test

A test on this unit alone, marked as a percentage and a letter grade — for the test your class is actually sitting, rather than for May. Answer everything, then submit once: seeing the answer to question 3 before attempting question 4 makes the final percentage meaningless.

Paper 1Paper 2Paper 3
Each paper is built from this unit’s 28 terms and is the same for everyone, so a teacher can assign “Unit 5, Paper 2” and every student sits the identical test. Multiple choice is marked objectively; the written sections you mark yourself against the model answer and rubric.
Suggested time 36 min 33 points0/17 attempted
1

Pleiotropy

2

Nondisjunction

3

Wild type vs mutant

4

Monohybrid cross

5

Epistasis

6

Law of segregation

7

Barr body and X-inactivation

8

Carrier

9

Dihybrid cross

10

Sex-linked inheritance

11

Interpreting error bars

12

Mean, standard deviation, standard error

Short answer 1. Define or explain: Multiple alleles

3 pts

Short answer 2. Define or explain: Degrees of freedom in chi-square

3 pts

Short answer 3. Define or explain: Law of independent assortment

3 pts

Short answer 4. Define or explain: Punnett square and probability

3 pts

Free response

9 pts

In fruit flies, body color and wing shape are determined by two genes. Gray body (G) is dominant to black body (g), and normal wings (N) are dominant to vestigial wings (n). A researcher crossed a female fly heterozygous for both traits with a male that was black-bodied and vestigial-winged. The offspring were counted. TABLE 1. PHENOTYPES OF 1,000 OFFSPRING Phenotype Number observed Gray body, normal wings 412 Black body, vestigial wings 398 Gray body, vestigial wings 94 Black body, normal wings 96

(a)(i) Identify the genotype of the female parent.

(a)(ii) State the phenotypic ratio that would be expected among the offspring if the two genes assorted independently.

(b)(i) Based on Table 1, state whether the data are consistent with independent assortment.

(b)(ii) Justify your answer in (b)(i) using the data.

(c)(i) Identify the two offspring phenotypes that resulted from crossing over during meiosis in the female parent.

(c)(ii) Calculate the recombination frequency between the two genes.

(d)(i) Using your answer to (c)(ii), estimate the distance between the two genes in map units.

(d)(ii) Explain why the recombination frequency between two genes on the same chromosome cannot exceed 50 percent.

(e) Explain why the researcher used a black-bodied, vestigial-winged male as the other parent in this cross.