QCAA Biology Functioning ecosystems and succession
5 sample questions with marking guides and sample answers · Avg. score: 73.4%
The table shows data on four plant species. Which is most likely to be a pioneer species?
| Germination rate | Presence of nitrogen-fixing bacteria | |
|---|---|---|
| A | slow | present |
| B | slow | not present |
| C | rapid | present |
| D | rapid | not present |
Row A
Row B
Row C
Row D
The process of change in the species structure of an ecological community over time is known as
cyclic succession.
primary succession.
ecological succession.
secondary succession.
An investigation compared mangrove species diversity for two areas of different size in the same catchment.
The table shows species population counts for each area.
Total species count
| Area 1 | Area 2 | |
|---|---|---|
| Grey mangrove | 37 | 7 |
| Red mangrove | 32 | 3 |
| Yellow mangrove | 25 | 88 |
| SDI | 0.67 | ? |
Calculate Simpson's diversity index for Area 2. Show your working.
SDI = ____________________ (correct to two decimal places)
Using your answer for Question 12a), compare the diversity of the two areas.
A glacier has retreated, leaving a large amount of gravel, small rocks, sand and mud.
Explain the steps of succession that would occur if the glacier continues to retreat.
Identify the type of ecological succession.
Two species of Paramecium, single-celled microorganisms, were grown for 4 days in test tubes with a fixed amount of algae added to each tube daily as their food source. The life span for each species ranges from 4–6 hours.
Test tubes 1 and 2 each contained a single species, and test tube 3 initially contained both species.
| Live Paramecium population after 4 days (per mL) | ||
|---|---|---|
| Test tube | Species A | Species B |
| 1 | 245 | 0 |
| 2 | 0 | 104 |
| 3 | 120 | 0 |
Identify and describe the ecological principle that relates to these observations.
Explain the results of the experiment.