degeneration. deterioration; change from a higher to a lower form, especially change of tissue to a lower or less functionally active form. When there is chemical change of the tissue itself it is true degeneration; when the change consists in the deposit of abnormal matter in the tissues, it is infiltration.apetoretinal degeneration degeneration of the pigmented layer of the retina. transneuronal degeneration atrophy of certain neurons after interruption of afferent axons or death of other neurons to which they send their efferent output.
There are four different DNA nucleotides, each defined by a specific nitrogenous base: adenine (often abbreviated A in science writing), thymine (abbreviated T), guanine (abbreviated G), and cytosine (abbreviated C) (Figure 2).
The DNA nucleotide consists of three parts: a phosphate group, a  5-carbon sugar, and a nitrogenous base. The portion of the  nucleotide that contains a negative charge is t â¦ he phosphate group. nucleotide is the building block (or monomer) of a nucleic acid chian The three parts of a nucleotide are: A base-A, T, G or C in terms of DNA and U insted of T in RNAA su â¦ gar-deoxyribose in DNA and ribose in RNAA phosphate group. 7 people found this useful. Answered.