Unit 5: Heredity
Biology · Unit 5 · Paper 3

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 3” 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

Environmental effect on phenotype

2

Punnett square and probability

3

Barr body and X-inactivation

4

Multiple alleles

5

Pleiotropy

6

Monohybrid cross

7

Dihybrid cross

8

Mean, standard deviation, standard error

9

Law of independent assortment

10

Linked genes

11

Interpreting a chi-square result

12

Degrees of freedom in chi-square

Short answer 1. Define or explain: Genotype vs phenotype

3 pts

Short answer 2. Define or explain: Test cross

3 pts

Short answer 3. Define or explain: Incomplete dominance

3 pts

Short answer 4. Define or explain: Pedigree analysis

3 pts

Free response

9 pts

This course has no free-response prompt tagged to this unit, so one from elsewhere in the course is used. It is still worth writing — the skill transfers.

In a beetle population, dark body color (D) is dominant to light body color (d). Among a random sample of 1,000 beetles, 360 are light-colored.

Calculate the frequencies of the D and d alleles, showing your work.

Calculate the expected numbers of homozygous dominant and heterozygous beetles in the sample.

State two conditions that must hold for a population to remain in Hardy–Weinberg equilibrium.

After ten generations on a dark volcanic substrate with heavy bird predation, only 90 of 1,000 beetles are light-colored. Calculate the new frequency of the d allele and identify the mode of selection acting on the population.

Explain why the d allele is unlikely to be eliminated from the population entirely.