Answer: The three mentioned substances (nucleotide, amino acid and glucose) are the BASIC UNITS of its various biological macromolecules.
Explanation:
NUCLEOTIDE is defined as the BASIC UNIT or the building block of nucleic acid such as Deoxyribonucleic (DNA) and Ribonucleic (RNA). It contains a sugar molecule, a phosphate group and a nitrogen containing base. They have a variety of functions which include:
--> they are the building blocks of substance that control hereditary characteristics.
--> energy carriers,
--> components of enzyme cofactors, and
--> chemical messengers.
AMINO ACID: This is defined as the BASIC UNIT that makes up the biological macromolecule known as PROTEIN which helps in the growth and repair of worn out tissues of the body.
It is made up of basic amino group, an acidic carboxyl group, and a unique organic side chain.
GLUCOSE: This is also the BASIC UNIT of the biological macromolecule called carbohydrates. They are also called simple sugars which are the body's preferred source of energy in the form of carbohydrates.
A) A transgene integrated into a heterochromatic region of the genome.
Explanation:
This is most likely the reason why the transgene is not expressed in the fifth cell line. It is likely that the transgene was integrated into a heterochromatic region of the genome. Heterochromatin consists of genetically inactive satellite sequences, and many of these are repressed to various extents. Moreover, because this is a tightly packed form of DNA or condensed DNA, it is inaccesible to polymerases and thus not transcribed.