Self-study
The three-spine stickleback is a small fish that lives both in oceans and in freshwater lakes. █████ █████ ███████████ ███ ███████ ████ █████ ██ ███████ ████ ████ █████ ██████████ ████ ███████████ ████ █████████ ██ ██████ █████ █████ ██████ ███ █████ ██ █ █████████████ ███████ ████ █████████ ████ ██████ █ ██████ ████ ██ █ ██████ ███████ ███████ ███ ████ █████████████ █████████ ████ ██████ ██████
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that a lake stickleback’s having a larger size is a better defense against its predators than having armor. This is based on the fact that ocean stickleback have armor for protection, whereas lake stickleback have almost no armor. In addition, armor limits the speed of a stickleback’s growth.
Notable Assumptions
The author assumes that lake stickleback are larger than ocean stickleback. In addition, the author assumes that the need to protect from its predators is the reason lake stickleback are larger and lack armor.
26.
Which one of the following, ██ █████ ███████ ███ █████████
a
Sticklebacks with armor ███ ██████ ██ ████ ██ █████ ██████ ████ ████ ██████████ ██ ███████████ ██████████
This is a disadvantage of having armor. This doesn’t undermine the author’s hypothesis, because it’s possible lake predators are fast-moving, making armor less effective against them.
b
Having a larger ████ ██ ██ █████████ ██████ ██ ███████ ████ ████████████ ███ ███ █████ ████████████ ███████ ████ ████████
This raises a potential alternate explanation for the lake stickleback’s larger size. The author thinks the larger size must have something to do with protection from predators. But it might instead be due to the need for surviving cold winters.
Alternate explanation
Alternate explanation
Weaken: Introduce or support an alternate explanation for a phenomenon.
Strengthen: Helps to eliminate an alternate explanation for a phenomenon.
c
Unlike ocean stickleback, ███ ████ ███████████ ███ ████ █████ ██████ ████ ██ █████████ ███████ ████ ██ ██████ █████
This doesn’t undermine the author’s hypothesis, unless you make the unwarranted assumption that a larger size wouldn’t be necessary or more effective at deterring insect predators. We have no reason to think a larger size is better defense than armor only against larger fish.
d
Both ocean stickleback ███ ████ ███████████ ████ █████████ ██ ███ ████ █████ ██ ██████
This concerns the diet of each stickleback. This has no clear relationship to lake sticklebacks’ larger size or lack of armor.
e
Sticklebacks originated in ███ █████ ███ █████ ██████████ ██████████ █████ ███ ███████ █████████ ███ ████ ███ ████
This relates to the origin of sticklebacks. This has no clear relationship to lake sticklebacks’ larger size or lack of armor.