Nitrogen-fixing bacteria live in in protective nodules (bumps) on the roots of some plants. a. mutualism. b. predation. c. commensalism. d. parasitism.

Guinea pig coat color is determined by a single gene. the allele for black coat color is dominant to brown. in a cross between twoblack-haired guinea pigs, 20 offspring are born. if both parents were heterozygous, probability would predict that approximately howmany of the 20 offspring would have brown hair?

18. over time, how do sand dunes tend to migrate? a. perpendicular to the movement of the wind b. in the same direction as the wind blows c. toward the wind d. in random directions

Scientists are conducting a study on the effectiveness of a new drug on memory loss. they are giving some of the test subjects the new drug to find out if it improves their long-term memory. which are possible limitations of this study? check all that apply. a) test subjects may want to participate in additional experiments. b) test subjects may think they should be paid more. c) test subjects may get bored and want to quit early. d) test subjects may have to travel during the experiment. e) test subjects may have full-time jobs. this is multiple choice. you for the !