Which statement is true regarding active transport? group of answer choices substances do not require additional energy to move in and out of cells. substances can only move into cells, not out of cells. substances can only move across the cell membrane if they are water soluble. substances can move from areas of low concentration to areas of high concentration.

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?

Do plant cells perform cellular respiration?

Which type of mutation occurs in reproductive cells and can be passed to offspring? somatic mutation germline mutation point mutation frameshift mutation