Answer:
B. The membrane lets certain substances move across it freely, while others must move through a “gate”.
Explanation:
Selective permeability is a property of cellular membranes that only allows certain molecules to enter or exit the cell. This is important for the cell to maintain its internal order irrespective of the changes to the environment. For example, water, ions, glucose and carbon dioxide may need to be imported or exported from the cell depending on its metabolic activity. Similarly, signaling molecules may need to enter the cell and proteins may need to be released into the extracellular matrix. The presence of a selectively permeable membrane allows the cell to exercise control over the quantum, timing and rate of movement of these molecules.
Answer: Portrayal of thermal convection as a mechanism.
if its not right im srry :(
but if it is your welcome :D
Answer:
sun to plants, plants to animals, animals to waste I believe
Answer:
is the surface where the water pressure head is equal to the atmospheric pressure
Explanation:
is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with water.