A student wanted to see if covering a leaf in foil would stop it from producing starch. Why should the student put the plant in a dark cupboard for 48 hours before returning it to the light and starting the experiment? 1. To make the results reliable
2. So that the plant would photosynthesise faster when returned to the light
3. So that any starch already in the leaf was used up by the plant
4. He did that simply

How did the miller-urey experiment impact the way scientists think about the origins of life? use what you know about the miller-urey experiments to discuss the factors needed for life to arise, and speculate on whether life could arise on another planet.

One of the newest applications of cell technology is called cybrid embryos. this process involves replacing the nuclear material of an animal cell with human nuclear material. how might this process affect public policies about research by using stem cells? the same policies and concerns about the use of human embryonic stem cells would most likely apply. the embryos would most likely be treated like traditional animal embryos and regulated accordingly. the process of forming cybrid embryos would most likely be banned by government regulators. the embryos would be treated as regular cells because they are not fully human in origin.

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.