Answer:
The correct answer is A.
Explanation:
Diffusion is the net movement of a substance from a region of higher concentration to a region of lower concentration. The difference in concentration between two environments creates a concentration gradient which is what drives diffusion. Therefore, this movement does not require aid such as extra energy molecules for active transport or integral membrane proteins for directed movement, hence the answer is not B nor C. If the cell is in equilibrium with its environment, it means that the concentration of substances inside the cell is equal to the concentration outside the cell, and any movement that takes place will be random movement of substances across the plasma memberane. Movement in the cell will not cease as the cell is still active. Therefore, the answer cannot be D either.
The answer is urethra.
It is known that the kidneys are responsible for filtration of metabolic wastes from the blood and form urine. Urine is transported through the ureters to the urinary bladder. From the urinary bladder, urine is transported to the outside of the body by the urethra.
Answer:
Its D, The cell membrane(also known a the plasma membrane) has a job in which it has to allow passage in and out of the cell. Therefore it can prevent harmful substances from entering the cell. Think of it as security, either allowing you access or denying you depending on if you're a threat
