Question 19

[icandoit2]

HI!! I really have no idea why B isn't the answer for #19. I don't understand the reasoning in the explanation. It really doesn't make sense to me.

How can the paraiste pop increase if there is a low host pop to feed on?
thanks



19. Which of the following is the least likely explanation of the results obtained for the control group in Fig. 1?

a. A low parasite population results in a lowered host population by the sheer virulence of the parasite. [x]
b. A low host population can increase a parasite population by eliminating their source for food. [x]
c. A high parasite population destroys the host population resulting in a lowered host population. [x]
d. A high host population creates a breeding ground for parasites thus increasing the parasite population. [x]
INCORRECT:

[admin]

I think we agree that C and D are fine. The challenge is between A and B. And frankly, this is too close to call so it has been scored as a test question.

Consider A for a moment:

"A low parasite population results in a lowered host population by the sheer virulence of the parasite."

Fig 1 clearly shows repeatedly that a low parasite population permits the host to start to grow again and thus the host population increases. Answer choice A directly contradicts what Fig 1 demonstrates making answer choice A the correct answer.

[Shain451130]

It would be nice to be able to reference the explanation and type here simultaneously. I specifically remember the explanation describing choice A as "illogical" yet it is listed as the correct answer. The graph seemed to reflect a allopatric symbiosis that more closely resembles the need for host population size to come before parasite proliferation (I can't remember which letter that answer corresponds to, but that's the one I marked). Please elaborate on the explanation.

[calena7178147]

The question asks for the LEAST likely explanation for the graph. Answer A is not likely, because it states that a low parasite population results in a lowered host population by the sheer virulence of the parasite. The graph does not have an area where a low number of parasites are seen before a low number of hosts.

[hua8986059]

pretty nasty passage lol.. I saved this one for the last, and still ended up missing the most on this passage. (spent 15 min on it.... )