We summarize natural selection as "survival fittest". what factor "selects" the fittest organisms in natural selection?

Consider the model of the oxygen cycle on earth. the majority of earth's oxygen reservoirs are found in the a) atmosphere. b) biosphere. c) hydrosphere. d) lithosphere.

Astudent wants to test the hypothesis that fertilizer improves the growth rate of grass seeds. to test this hypothesis, the student put the same amount of grass seed in 3 containers with the same type of soil. the student measured the growth at the end of the week. all plants received equal amounts of water and sunlight. if you were asked to graph this data, what would you place on the x-axis? a. fertilizer b. water c. plant growth d. week one

Which of these parts of the membrane large moecules pass through it ?