The answer is C
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Answer: DNA has three components a phosphate group, a sugar deoxyribose and 4 nitogenous bases.
DNA has two important bonds that make up the DNA which are phosphodiester bond and hydrogen bonds.
Explanation:
The phosphate of the one nucleotide in DNA bonds with the 5 sugar (5' carbon) of the next nucleotide forming the PHOSPHODIESTER BOND which is a strong covalent bond.
The other bond in DNA is the hydrogen bonds which are among the nitrogenous bases.
There are four bases adenine,guanine,cytosine,thyamine
These bases are held together by strong hydrogen bonds.
Adenine and thyamine have two hydrogen bonds between them and cytosine and guanine have three hydrogen bonds between them.
These hydrogen bonds keeps the DNA helix in place.
Answer:
d. ocean circulation patterns are affected by global cooling
Explanation:
According to current studies, during glacial periods the change of ocean circulation and the increase of its productivity contributed to the reduction of atmospheric CO2 levels. As a result, this reduction influenced the cooling of the poles and the expansion of the Antarctic ice sheets in the Cenozoic period. Therefore <em>the change in ocean circulation</em> influences the <em>cooling of the earth.</em>
