Unit 3: Populations
Env. Science · Unit 3 · Paper 2

Populations 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 33 terms and is the same for everyone, so a teacher can assign “Unit 3, 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 37 min 34 points0/17 attempted
1

Replacement level fertility

2

Crude birth and death rates

3

Population pyramid shapes

4

Why a logistic curve is S-shaped

5

Why Stage 2 grows fastest

6

IPAT equation

7

Infant mortality rate

8

Population growth rate calculation

9

r-selected species

10

Demographic transition

11

Logistic growth equation

12

Exponential growth equation

Short answer 1. Define or explain: Age structure diagram

3 pts

Short answer 2. Define or explain: Factors that lower birth rates

3 pts

Short answer 3. Define or explain: Total fertility rate

3 pts

Short answer 4. Define or explain: Why replacement fertility is 2.1, not 2.0

3 pts

Free response

10 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.

A city plans to build a coal-fired power plant beside a wetland. Ecologists worry that acid deposition will lower the pH of the wetland and reduce amphibian egg survival. Before construction, the city funds a two-year study of amphibian breeding pools.

Identify the independent variable the researchers should measure.

Identify ONE dependent variable they should measure.

Describe an appropriate control or comparison group for this investigation.

Explain why that comparison group must otherwise resemble the treatment pools.

Identify ONE variable that must be held constant across sampling sites.

Justify why that variable must be held constant.

Describe the method and instrument the team should use to collect the pH data.

State how often and at what time of day the samples should be taken.

Make a prediction about the results if the acid-deposition hypothesis is correct.

Identify ONE limitation of this investigation and explain why it weakens a claim that the plant CAUSED any change.