the function of an organism has a hole is the outcome of the combined activities and interaction of the constituents of the cell give reason

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

Which of the following is a limitation of a clinical trial? a.)amount of random assignments b.)hospital cost c.)number of test tubes d.)amount of peer review

Which of the following best describes the expensive tissue hypothesis? brains require more energy, so the gut had to be reduced, and larger brains and tool use led to higher quality diets. increasing body size means that homo neanderthalensis had to include more fat in its diet. brains require more energy, so the gut had to be reduced as brains got bigger. brains require more fat, so the gastrointestinal viscera (gut) had to expand, and hands were needed to acquire more food.