Help me please!!! Science?

Question

Scientists performed an experiment to determine whether there is a connection between learning ability and food. They took two groups of 20 mice each, all from the same purebred strain. The mice were deprived of food for 3 days and then given a standard learning session in running through a maze. They were trained by giving them a mild electric shock whenever they took a wrong turn. Immediately after each learning session, one group of mice was fed, but the other was not, A week later, all of the mice were tested to see whether they could still run the maze correctly. The group that had been fed had retained this ability, but the other group had not. The probable reason that the scientists used only mice from the same pure-bred strain is so that:

a)the mice would all be the same size

b)the mice would all be the same color

c)the experiment could be repeated with the same mice

d)genetic differences would not affect the outcome of the test

e)the experiment wouldn't cost

Answer 1

d) is the correct answer, but c) is technically correct too.

a) There is size and weight variation, even between mice from the same litter.
b) There is color variation, even between mice from the same litter.
e) Please let me know where this is possible. I'd move our transgenic mouse colony there in a second.

c) is technically correct, but the "learning" process from the previous experiments would influence the outcome of subsequent experiments.

On a side note, I'm not sure too many still use electrical shock stimuli as a deterrent in rodent experimentation. It seems a little barbaric. The "reward" of food should be enough incentive to learn. I also wouldn't recommend food deprivation for 72 hours on mice. Since their metabolic rate is about 7 times that of a human, it would be equivalent to starving a human for 3 weeks.

Answer 2

d.

Genetic differences are more likely to affect learning ability than size and color, ruling out a and b. The mice don't need to be identical for the experiment to be repeated; you can just use the same mice again, or get the same type of mixed-breed mice, ruling out c. Cost isn't as important a factor as quality of the experiment, plus pure-bred mice probably cost more, not less, ruling out e.

Answer 3

D- Genetic difference could be a confounding variable, so by using mice with the same genetic pattern they can control for that.

Answer 4

D of course

Answer 5

In my opinion, it's D. It's which makes more sense.

Answer 6

The answer is D.

Answer 7

ohhh D.