Which cell stucture is responsible for the passage of material into and out the cell

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

18. over time, how do sand dunes tend to migrate? a. perpendicular to the movement of the wind b. in the same direction as the wind blows c. toward the wind d. in random directions

Ascientist is designing an investigation to study the impact of invasive bird populations on local, native bird populations at backyard bird feeders. what population is most likely to be a control group for the investigation? amount of food number of bird feeders invasive bird populations local backyard birdfeeders without food