Answer:
While it is difficult to determine exactly how many Natives lived in North America before Columbus, estimates range from a low of 2.1 million to 7 million people to a high of 18 million.
Explanation:
<span>swimming by large fish</span>
Answer options:
- extraction and observation of DNA
- identification of ribose and deoxyribose
- recognition of RNA as DNA’s messenger
- construction of an accurate DNA model
Answer:
- identification of ribose and deoxyribose
Explanation:
Phoebus Levene was an American biochemist who studied the structure of DNA and RNA. He was able to isolate the sugars (ribose and deoxyribose) from the nucleic acids, which are an important part of their structure.
He also determined how the nucleic acid components combine to form the nucleotides, the basic building blocks of nucleic acids, and how the nucleotides combine in chains to form the polymer.
The first sentence is true