Question 18M.3.HL.TZ1.15
| Date | May 2018 | Marks available | [Maximum mark: 6] | Reference code | 18M.3.HL.TZ1.15 |
| Level | HL | Paper | 3 | Time zone | TZ1 |
| Command term | Compare and contrast, Predict, State | Question number | 15 | Adapted from | N/A |
A retreating glacier leaves an environment of lifeless glacial deposits, including sands and gravels. Retreating glaciers often offer suitable sites for primary succession.
State one abiotic factor that will determine the type of ecosystem in a succession.
[1]
temperature/precipitation/rainfall/minerals /pH of soils/light/humidity/wind/slope (in this specific example)
A retreating glacier leaves an environment of lifeless glacial deposits, including sands and gravels. Retreating glaciers often offer suitable sites for primary succession.
Predict the process of succession that takes place on exposed bare ground as the glacier retreats.
[3]
a. (bare ground) colonized by microorganisms/pioneer species
b. thin soil forms from rock fragments / decomposing organisms
c. soil retains water from melting permafrost/ice
d. grasses/small plants/herbaceous plants/moss grow
e. (larger plants) create habitat for animals
f. weather/climate may limit plant size/biodiversity
OR
climax community forms
Compare and contrast food chains and food webs.
[2]
Similarities:
a. in both food webs and chains organisms are arranged by trophic levels/feeding positions
b. both represent the transfer of food/energy in an ecosystem
c. both include producers and consumers
Differences:
d. one species could occupy different trophic levels in a food web but not in a food chain / converse
e. food chain represents one possible feeding option for each organism but food web represents more possible feeding relationships/trophic levels
OWTTE
(max 1 for similarities)
(max 1 for differences)