Unit 8: Ecology
Biology · Unit 8 · Paper 3

Ecology 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 42 terms and is the same for everyone, so a teacher can assign “Unit 8, 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 31 min 28 points0/17 attempted
1

Ten percent rule

2

Species richness vs evenness

3

Symbiosis types

4

Simpson's diversity index

5

Nitrogen fixation

6

Ecosystem services

7

Biodiversity and stability

8

Population growth rate

9

Fundamental vs realized niche

10

Mimicry

11

Trophic levels

12

Carbon cycle

Short answer 1. Define or explain: Limiting nutrient

3 pts

Short answer 2. Define or explain: Gross vs net primary productivity

3 pts

Short answer 3. Define or explain: Eutrophication

3 pts

Short answer 4. Define or explain: Primary vs secondary consumers

3 pts

Free response

4 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 gene in a bacterium is transcribed only when lactose is present in the growth medium and glucose is absent.

Identify whether this operon is inducible or repressible, and justify your answer.

Explain the role of the repressor protein when lactose is absent.

Explain the advantage to the bacterium of regulating these genes rather than expressing them constantly.