Question 18N.3.SL.TZ0.15b
| Date | November 2018 | Marks available | [Maximum mark: 4] | Reference code | 18N.3.SL.TZ0.15b |
| Level | SL | Paper | 3 | Time zone | TZ0 |
| Command term | Deduce | Question number | b | Adapted from | N/A |
When water rises above a certain temperature, coral bleaching may occur. The coral expels Zooxanthellae algae living in its tissues, leaving the coral a white colour. The graph shows how the water temperature is changing in the coral reefs surrounding the Cayman Islands.
Deduce the effect of bleaching on corals.
[4]
a. the coral and the algae have a symbiotic/mutualistic relationship
OR
two different organisms live together and depend on each other ✔
b. algae expelled from coral/relationship broken ✔
c. coral produces carbon dioxide from respiration ✔
d. the algae use the carbon dioxide to carry out photosynthesis/produce nutrients ✔
e. without the nutrients from the algae the coral are liable to starve ✔
f. coral dies/is susceptible to disease ✔
Do not accept effects on species other than coral
