Answer: polyunsaturated fatty acid residues
Explanation: Unsaturated fatty acids have a lower melting point so arctic animals have these fatty acids in their membranes.
Lipids are not polymers because they contain one molecule and are not macromolecules.
A force is a push or a pull. When one object pushes or pulls another object, you say that the first object is exerting a force on the second object.
I disagree it should be A
For the first question-a bicep is a large muscle in the upper arm which flexes the arm and forearm, a tricep is a large muscle at the back of the upper arm and a deltoid is a thick triangular muscle covering the shoulder joint and used for raising the arm away from the body.