Which letter indicates a cell structure that directly controls the movement of molecules into and out of the cell?

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?

Pls need ! in your opinion, what are the limiting factors that might affect the growth or diversity of our ecosystem? respond to this question in claim, evidence, reasoning format. 1. make your claim (i are the limiting factors that might affect the growth or diversity of our 2. follow the claim with 3 pieces of evidence. evidence may be taken from the reading, the videos, previous lessons, or googled answers. site sources, too. 3. use reasoning to explain why you chose your evidence.

What evidence could be used to convince policy makers to change a shipping lane from going through a whale breeding ground? information on the number of all whale species currently alive information on the number of all whales hit by boats in the given area information on the number of whale deaths in the world's oceans information on the number of whale offspring born every year. (a) scientists could collect and combine data on fish populations all around the world to show that their populations are declining. (b) scientists collect and combine data on fish populations all around the world to show that their populations are increasing. (c) scientists work together and use past data to show that fish populations are becoming locally extinct in some areas. (d) scientists work together and use past data to show that some fish populations are adapting to environmental changes.