Question 18M.2.SL.TZ1.c
| Date | May 2018 | Marks available | [Maximum mark: 7] | Reference code | 18M.2.SL.TZ1.c |
| Level | SL | Paper | 2 | Time zone | TZ1 |
| Command term | Explain | Question number | c | Adapted from | N/A |
The structure of organisms is based on organic molecules containing carbon. Explain the cycling of carbon in an ecosystem.
[7]
a. autotrophs/producers absorb carbon (dioxide} from atmosphere/air/water
b. autotrophs make carbohydrates/organic compounds / perform photosynthesis
c. carbon (compounds) pass along food chains/trophic levels (as consumers feed)
d. respiration releases carbon (dioxide) into atmosphere/water
e. carbon (dioxide} is released from dead matter /by decomposition/respiration
f. methane is produced during anaerobic respiration of organic matter / by methanogens in cattle/herbivores
g. methane is oxidized into carbon dioxide in the atmosphere
h. fossil fuels/peat were made from partially decomposed organic matter
i. combustion of fossil fuels/forest fires/biomass releases carbon (dioxide} into the atmosphere
j. volcanic eruptions may add large quantities of carbon (dioxide) into the atmosphere
k. limestone (from shells/reefs)/trees/permafrost are sinks of carbon
