Question

46.

Researchers studying succession in three forest sites want to determine how similar the forests are in terms of species composition. Using Jaccard’s index, determine which pair of forests has the LOWEST similarity.

Tree Species	Forest A	Forest B	Forest C
Acer saccharum	X	X
Fagus grandifolia	X	X	X
Quercus rubra	X		X
Quercus alba	X		X
Acer rubrum	X	X
Prunus serotina		X
Liriodendron tulipifera	X	X
Carya ovata	X		X

Group of answer choices

A. Forest A & Forest B

B. Forest A & Forest C

C. Forest B & C

D. Forests A & B have equal similarity to Forests A & C

E. Forests A & C have equal similarity to Forests B & C

47).

A grassland habitat produces 5,000,000 available food calories per day from plants. If each organism in the community requires 1,000 calories per day, how many organisms could survive if feeding at the level of a primary consumer? What about if all fed at the level of a secondary consumer?

Group of answer choices

A. 50; 5

B. 50; 500

C. 500; 50

D. 5,000; 500

E. 5,000; 50

Researchers working at high-elevation sites in the Alaska Range and High Andes of Peru conducted a nutrient addition experiment to see how the addition of nitrogen and phosphorous individually and together affect the cover (abundance) of plant species. They conducted 3 separate t-tests to analyze their results. For the test to determine whether percent cover was significantly different between the +N and +P treatments, they calculated a p-value of 0.002. For the test of a difference between +N and +N+P treatments, they calculated a p-value of 0.001. And finally, for the test of a difference between the +P and +N+P treatments, they calculated a p-value of 0.46.

According to the experimental results described and shown in the figure above, which of the following statements are true? Select ALL that apply.

Group of answer choices

A. The addition of nitrogen had a larger effect than the addition of phosphorous and this effect was statistically significant.

B. The addition of phosphorous had a larger effect than the addition of nitrogen this effect was statistically significant.

C. Adding both N & P increased plant cover significantly more than adding either N or P alone.

D. Nitrogen is more of a limiting nutrient than phosphorous in this system.

E. Phosphorous is more of a limiting nutrient than nitrogen in this system.

Answer 1

46) Answer C: Forest B and C has lowest similarity.

According to jaccard's index

Number in both sets / number in either sets multiplied by 100

A and B forest sites share four species among the total eight species .4/8 = 1/2 *100 =50%

A and C Forest sites also share four species among the total eight species.4/8 = 1/2 *100=50%

Forest A and B & A and C has similar similarity.

B and C Forest sites share only one species among the total eight species so this pair only has lowest similarity.1/8 *100= 12.5%

47) Answer : C - 500:50

Total calories produced in the grassland habitat is 5,000,000 per day

Each organisms require 1,000 calories per day

So the number of organisms in the producers level will be 5,000,000/1,000 = 5000

Each level of the pyramid gets 10% less energy than the level below .

Calories used by primary consumers will be 10% less than producers so it has 5,000,000÷ 10 = 5,00,000.

The number of organisms in the next level ,primary consumers will be 5,00,000÷ 1,000= 500

Calories used by secondary consumers will be 10% less than primary consumers 5,00,000÷ 10 = 50000

Number of organisms in the secondary consumers level will be 50000÷1000 = 50