Answer:
<u>A chemical bond between the phosphate group of one nucleotide and the sugar of a neighboring nucleotide holds the backbone together. Chemical bonds (hydrogen bonds) between the bases that are across from one another hold the two strands of the double helix together.</u>
Explanation:
Answer:
an element is a pure substance which can not be spilt into simpler substances by chemical means
Explanation:
examples hydrogen, oxygen, copper