The atmosphere also protects living things on Earth from the sun's harmful ultraviolet radiation. A thin layer of gas called ozone high up in the atmosphere filters out these dangerous rays. The atmosphere also helps to sustain life of Earth.
A.) Organic fossils. I hope that's right
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Answer:
It requires energy
Explanation:
In the coupled transport system, coupled carriers couple the inward transport of one solute across the membrane to the outward transport of other solutes across the membrane. The tight bonding that occurs between the transport of two solutes allows these carriers to utilize the energy stored in one solute, usually an ion, to facilitate transport of the other. With this way, the free energy released during the movement of an ion down an electrochemical gradient is utilized as the driving force to transport other solutes inwards, against their electrochemical gradient.