Course
Ecology
Study Pack
Set 9 Population Distribution And Abundance
Question 1
(Multiple Choice)
Free
Some Aleutian Islands are surrounded by urchin barrens while others are surrounded by kelp forests. Which statement gives the primary explanation for these differences?
A) Kelp forest islands and urchin barren islands differ with respect to oceanic currents.
B) Kelp eat urchins, thus preventing their establishment.
C) The kelp forest islands experience a substantially warmer climate than do the urchin barren islands.
D) Grazing by urchins prevents the formation of kelp forests.
Answer
Question 2
(Multiple Choice)
Free
Which statement about Duggins's urchin removal experiments is true?
A) Kelp was abundant in both the urchin-excluded and the control treatments at the start of the experiments.
B) Kelp did not become established in the control treatment.
C) Kelp did not become established in the urchin-excluded treatment.
D) Urchins died in the control treatment due to the presence of kelp.
Answer
Question 3
(Multiple Choice)
Free
Refer to the figure.
Assume that the number of individuals of Laminaria is on a linear trajectory in the figure. If Duggins had sampled the kelp density 1.5 years after urchin removal, predict the approximate number of individuals of Laminaria he would have counted.
Assume that the number of individuals of Laminaria is on a linear trajectory in the figure. If Duggins had sampled the kelp density 1.5 years after urchin removal, predict the approximate number of individuals of Laminaria he would have counted.A) 20
B) 40
C) 60
D) 100
Answer