The ice has less density than liquid water, so it floats on the water surface. Therefore during the winter all the lakes and rivers are frozen only at a top. Deeper layers of water are cold, but still liquid and it allows fish and other organisms to survive. Moreover, the ice cover provides temperature isolation so liquid water beneath the ice has more or less constant temperature (around 4 dgr Celsius)
The provide direct energy because they help it grow plants and when plants grow it helps us live.
But it also provides indirect energy because the sun can cause droughts which is bad because with droughts we dont have enough water to water the plants and with that they dry out and die.
Reading background information because it gives ideas from the author himself.
Answer:
Like the plasma membrane, organelle membranes function to keep the inside "in" and the outside "out."
Explanation: