Answer:
To test the presence of protein in the food substance which gives a blue-to-purpule colour
Answer:
Physical digestion prepares the food for chemical digestion.
Lipids are unique because, they are made from one carbon skeleton unlike the other macro molecules groups which are made from smaller building blocks.
With the exception of steroid hormones, lipids are generally hydrophobic. Also lipids are relative small molecules when compare in size with other macromolecules.
C. Ball and socket joints
Just took the test hope this helps :)
Condensing point of the substance