| Date | November 2017 | Marks available | 2 | Reference code | 17N.3.HL.TZ0.15 |
| Level | Higher level | Paper | Paper 3 | Time zone | TZ0 / no time zone |
| Command term | Predict | Question number | 15 | Adapted from | N/A |
Question
Wild turkeys (Meleagris gallopavo) once inhabited most forested areas of North America. As an important food source for early European settlers, the population of M. gallopavo seriously decreased. Due to recent conservation efforts, population numbers are increasing.
[Source: https://commons.wikimedia.org/wiki/File:A_wild_turkey_in_Middleboro,_Massachusetts.jpg]
The curve shows a population of M. gallopavo from 2000 to 2015 in Ohio in the mid-western USA.
State the range of years when exponential growth of the M. gallopavo population occurred.
Suggest factors that could account for the growth curve of the M. gallopavo population.
State how the population of M. gallopavo may have been determined.
Hunting of M. gallopavo is currently regulated. Predict what would happen if the hunting regulations were removed.
Markscheme
2000–2008
a. natality AND mortality
b. immigration AND emigration
c. resources/abiotic conditions/carrying capacity
d. predation/hunting
[Max 2 Marks]
capture–mark–release–recapture/Lincoln/Peterson method
a. population would decrease/may become extinct
b. open realized niche for other organisms
OWTTE
c. food web may change
d. less intraspecific competition
[Max 2 Marks]
Examiners report
Syllabus sections
- 17N.3.HL.TZ0.15b: State how the population of M. gallopavo may have been determined.
- 19M.3.SL.TZ1.11c: Suggest one way in which depth may act as a limiting factor for coral.
-
16N.3.HL.TZ0.17a:
State two bottom-up factors affecting algal blooms.
- 18M.3.SL.TZ1.12c: State one method that could be used to estimate the isopod population size.
-
19M.3.HL.TZ2.16a:
Explain the factors that can contribute to the exponential growth phase in a sigmoid population curve.
- 16N.3.HL.TZ0.16a: Describe one method that could have been used to estimate the population size of a given tree...
- 17N.3.HL.TZ0.15a.i: State the range of years when exponential growth of the M. gallopavo population occurred.
- 18M.3.HL.TZ1.17a.ii: Suggest one possible cause for the decrease of the number of animals after 1940.
- 16N.3.SL.TZ0.14a: Outline the trend in the number of people with malaria during the period when the use of...
- 17M.3.HL.TZ2.15e: Explain how an excessive growth of algae on coral reefs can be controlled by top-down factors.
- 18M.3.HL.TZ2.15c: Explain how nutrients can have a positive or negative bottom-up effect on seagrass.
- 18M.3.HL.TZ1.17a.i: State the type of growth of this population up to 1940.
- 17M.3.HL.TZ1.17: Discuss the factors affecting population growth that can result in an exponential growth curve.
-
19N.3.HL.TZ0.18:
Explain the technique used to estimate the population size of a named species of organism that is able to move.
-
19M.3.HL.TZ1.19:
The garden snail, Helix aspersa, is a herbivore.
[Source: Sinan Önder /https://www.pexels.com/photo/animal-close-up-crawling-garden-243128/]
Explain how the population of snails in an ecosystem could be estimated by capture-mark-release-recapture, identifying the limitations in the method.
- 16N.3.HL.TZ0.17b: Explain how top-down factors control algal blooms.
- 19M.3.HL.TZ2.16b: Outline the effect of carrying capacity on the growth of a population.
-
17N.3.HL.TZ0.15a.ii:
Suggest factors that could account for the growth curve of the M. gallopavo population.
![https://commons.wikimedia.org/wiki/File:A_wild_turkey_in_Middleboro,_Massachusetts.jpg]](https://commons.wikimedia.org/wiki/File:A_wild_turkey_in_Middleboro,_Massachusetts.jpg]){kind=link}