Question 18M.3.HL.TZ2.16
| Date | May 2018 | Marks available | [Maximum mark: 6] | Reference code | 18M.3.HL.TZ2.16 |
| Level | HL | Paper | 3 | Time zone | TZ2 |
| Command term | Distinguish, Outline, State, Suggest | Question number | 16 | Adapted from | N/A |
The model describes the fundamental and realized niches of a species of microscopic marine arthropod in the Northern hemisphere with respect to two different factors (X and Y). The abundance of the species is shown over twelve months. The fundamental niche is separated into five zones ranging from critical to optimal conditions. The population of the species in its realized niche each month is represented by an oval. The size of each oval shows the population abundance.
Distinguish between fundamental niche and realized niche.
[1]
fundamental niche is all potential conditions a species could live in whereas realized niche is actual conditions under which the species live
State the month where the population reaches its maximum.
[1]
April
Outline how factor Y affects the species from January to April.
[2]
a. limited effect on low/stable population size from January to March
OWTTE.
b. large effect increases population size from March to April
OWTTE.
c. niche conditions decrease from January to March
d. niche conditions improve from March to April
Suggest, with a reason, what factor Y could be.
[2]
a. factor
eg temperature.
b. explanation
eg as temperature increases in spring «March to April» so the conditions for the species are more favourable.