Which discovery is attributed to Phoebus Levene? extraction and observation of DNA
identification of ribose and deoxyribose
recognition of RNA as DNA’s messenger
construction of an accurate DNA model

Answer options:

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.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.

the eggs of the insects should be the first thing collected at the scene.

false