A. the metric system is the most widely adopted
Answer: Option (c) is the correct answer.
Explanation:
A long hydrocarbon chain that consists a terminal carboxylic group is known as a fatty acid.
An unsaturated fatty acid consists a double bond within the fatty acid chain. If a fatty acid contains more than one double bond then it is known as polyunsaturated fatty acid.
For example, oelic acid has chemical formula 
is an unsaturated fatty acid.
Therefore, we can conclude that option (c) represents an unsaturated fatty acid.
Answer:
B.carries and allows expression of a foreign gene of interest.
Explanation:
Plasmids are the low molecular weight extrachromosomal DNA molecules that are able to replicate themselves independent of chromosomal DNA due to the presence of "ori" (origin of replication).
Plasmids serve as vectors in recombinant DNA technology as some of their genes can be replaced with the gene of interest to create recombinant plasmids.
The restriction enzymes that create the sticky ends and DNA ligases facilitate the insertion of the foreign gene into the plasmids.
The host cells are made competent to take up the recombinant plasmids. Once inside the host cell, the recombinant plasmids replicate themselves and express the gene of interest that they carry.
Proteins differ from one another primarily in their sequence of amino acids
