Macy always thought there were only a few hair colors: blond, brown, and black. However, when she actually began looking around, she saw varying shades of these hair colors. What is possible reason for so many different hair colors?

What goes in and out of a cell respiration?

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.

Why were the results whit just water so much different than the trials with the detergent ?