Bacteria that change nitrogen gas from the atmosphere into solid nitrogen usable by plants are called nitrogen-fixing bacteria. These bacteria are found both in the soil and in symbiotic relationships with plants.
The earth is surrounded by <em>a layer of</em> gases called the <em>atmosphere</em>. The atmosphere is very <em>important </em>to life on <em>Earth</em> and does many <em>things</em> to help protect life and help<em> life </em>to survive.
The atmosphere absorbs the <em>heat</em> from the <em>Sun </em>and keeps the heat <em>inside</em> the atmosphere helping the <em>Earth </em>to stay warm, called the <em>Greenhouse </em>Effect.
Answer:
5 bases
Explanation:
If there are 17 amino acids and only 2 bases that can be combined in order to make a codon then:
for 4 bases is 16 and it is not enough combination for all 17 amino acids
for 5 bases is 25 combinations (meaning that more than one codon could code for the same amino acid).
It's probably heat,if there are multiple choices it'll help if you could give them.