Sort the variables of these three studies based on whether they are independent or dependent variables. Study 1: the effect of light on flowering patterns of plants Study 2: the effect of penicillin on the growth of E. coli Study 3: the effect of progesterone on the ovulation of rats light flowering patterns progesterone penicillin growth of E. coli ovulation

Which of the following will not cause mass extinction? a. drastic change is weather b. geological change c. both a and b d. none of the above

This is a situation in which genes are attached to an organism's sex chromosomes; the sex of an organism influences the expression of a gene.

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.