Answer:
Active uptake (which I think you mean active transport) is important when the concentration gradient is against that of a certain substance, so it doesn't cross the membrane through diffusion or passive transport. It is sometimes necessary if a substance needs to move across a membrane but can't do so due to electrical charge or that there is a substance on the other side of the membrane preventing diffusion.
Explanation:
Answer:
C
Explanation:
In 1839, Theodore Swhwann, a German Zoologist examined bits of animals under a microscope and observed that animals were composed of cells.
Answer:
Land Insecurity
Very Poor Living Conditions
Unemployment
Crime.
To name a few
Um D? A fold?? If its right mark as brainleist please
