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:
The universe is the answer
Eye strain - hope this helped
A larger piece of plastic waist is worse
Answer:
○ D. Humans are using up natural capital faster than it is being replenished.
Explanation:
I assume this is the answer, due to the past/recent media on Earth and the economy.