3. What organelle is known as the “gatekeeper” and allows
nutrients to enter and exit the
cell?
A. Cell wall
B. Cell membrane
C. Nucleolus
D. Mitochondria

Whether or not a given study has the possibility of causing harm to participants:

Ascientist successfully predicts the outcome of an experiment. you watch carefully and know he didn't cheat. the scientist's success shows that: a) the scientist knows absolute truth about this experiment; success is not possible unless you know the truthb) the scientist was just lucky; no one ever knows what's going on, so successful predictions require luckc) the scientist may know the truth, or at least know something that is close to the truth, or the scientist may have gotten lucky this time; you can't be absolutely sured) the scientist really was cheating, even though you didn't see the cheating; no one can get things right, except by cheatinge) the scientist spent the night at a particular hotel chain and go a free breakfast, giving the scientist the ability to do amazing things

John recently received his semester grades and found that he had failed two courses. he says the reason he failed the two courses is that they were taught by female professors. john believes that women are really not smart enough to teach at the college level. in this example, the female professors are a) spacegoats and being blamed for john's grades b) being discriminatory toward john c) probably not smart enough to teach in a college d) prejudiced against john because he is male