Answer:
the unknown substance is a protein
Explanation:
The biuret test is one of the tests for proteins. It can be used to detect peptide linkages. The biuret test is carried out in an alkaline solution. A coordination complex is formed leading to the appearance of a violet color.
Summarily, the biuret method is a colorimetric technique used to test for proteins and peptides. It involves the formation of a purple (violet) complex of Copper salts in alkaline solution.
Hence when the biuret reagent is added to an unknown substance and it turns purple, the unknown substance is a protein
Energy from the sun that is neither reflected nor absorbed by the atmosphere passes through the atmosphere to the surface. The ozone layer absorbes most of the ultraviolet radiation, water vapor, and carbon dioxide absorbs infared radiation, clouds, dust, and other gases also absorb energy.
C ?
each sex cell has 23 unpaired cells, a regular cell would have 46.