Nyctalopia
Nyctalopia is the condition of night blindness characterized
by inability to see clearly at night or in dim light and the ability to see
clearly in the day. Deficiency of vitamin A leads to nyctalopia. Other possible
causes of Nyctalopia include myopia, cataract, retinitis pigmentosa and some glaucoma
medications.
The answer is A:
The SUGAR-PHOSPHATE CHAINS form the sides, and the BASE PAIRS form the rungs
Explanation:
A single nucleotide-pair substitution missense mutation causes a change of a single amino acid into another. Aa a result, the produced protein will have an almost normal sequence except for one amino acid.
On the other hand, a frameshift mutation changes the Open Reading Frame (ORF) of the ribosome. The ribosome moves along the mRNA every three nucleotides (codons) and translates them into amino acids that will form the nascent protein. If there is a frameshift mutation (an insertion or deletion of a number of nucleotides not multiple of three) the ribosome will "read" the mRNA differently and will identify different codons than the wild-type sequence, so a large number of amino acids will be different in the mutated protein.