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

cramming before a final is bad because it makes a student's stress level higher. students who embrace cramming to get through a final exam week find themselves struggling to perform consistently, once the brain adjusts to prolonged sleep deprivation.

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.