Unit 7: Natural Selection
Biology · Unit 7 · Paper 1

Natural Selection 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 38 terms and is the same for everyone, so a teacher can assign “Unit 7, Paper 1” 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

Heritability requirement

2

Phylogenetic tree

3

Evidence for evolution

4

Directional selection

5

Convergent evolution

6

Antibiotic and pesticide resistance

7

Speciation

8

Natural selection

9

Lab: Hardy-Weinberg modeling

10

Out-group in a cladogram

11

Artificial selection

12

Adaptive radiation

Short answer 1. Define or explain: Disruptive selection

3 pts

Short answer 2. Define or explain: Fitness

3 pts

Short answer 3. Define or explain: Coevolution

3 pts

Short answer 4. Define or explain: Cladogram and shared derived characters

3 pts

Free response

9 pts

In a population of beetles, body color is controlled by a single gene with two alleles. Dark color (D) is dominant to light (d). A researcher samples 1,000 beetles from a forest and finds 640 dark and 360 light beetles. The forest is then partly cleared, leaving pale soil across half the habitat, and birds hunt the beetles by sight.

Calculate the frequency of the d allele in the original population, showing your work.

Calculate the expected number of heterozygous beetles, assuming Hardy-Weinberg equilibrium.

Explain how the habitat change is expected to alter allele frequencies over several generations, and identify the type of selection involved.

A colleague argues the population is evolving because individual beetles are changing color to match the soil. Explain why this reasoning is incorrect.