To say that there is a "proofreading" function in DNA replication means that the DNA polymerase will be eliminating an improper nucleotide if it develops extra and it will exchange it with the right nucleotide so there are very few mistakes.
Natural selection
Tornado
Loss of food or water
Hurricane
Most of the time but not always. When it doesn't, it results in a gene mutation.
Answer:
hydroshpere and biosphere
Explanation:
it contains
hydrosphere: cleaning of water
biosphere: helps plants and animals
