Over the course of evolutionary time, animal body sizes have gotten larger, yet cell sizes have not. cells have stayed proportionally the same size to remain efficient, which is due to the fact that group of answer choices larger cells would become limited by the ability to move materials across the plasma membrane. the inability of the nucleus to produce sufficient dna for larger cells. limitations of the composition of the plasma membrane. both a and b if cells got larger, the demand for energy and raw materials would greatly increase.

Which process is involved in growing crops? irrigation transportation recreation condensation

Sally and sue were investigating the topic of friction in science. they used a small car and a ramp as seen in the picture to test what they were learning. they knew that they slipped easily on waxed floors but not on carpet, so they decided to change the material on the surface of the ramp to see what happened. they planned to use glass, carpet, aluminum foil, and sandpaper and run the car down the ramp over each surface. what would be the best research question to guide the girls' experiment? a) does the amount of surface area affect the friction on the moving car? b) will the car travel fastest on the glass surface? c) how does the angle of the ramp affect the speed of the car? d)do rougher surfaces tend to create more friction than smooth surfaces?

What sentence best supports the statement that hormones are involved in the regulation of homeostasis? a. the hormone erythropoeitin increases the production of red blood cells when oxygen levels are low. b. the hormone oxytocin promotes labor contractions of the uterus during childbirth. c. the hormone melatonin induces sleep and its production is slowed by exposure to light. d. the hormone cortisol suppresses the immune system and is produced when the body is under stress.