Answer:
The mentioned case is an illustration of the missense mutation. A missense mutation is a kind of nonsynonymous substitution, that is, it is a mutation in which a variation in a solitary nucleotide leads to the formation of a codon, which encrypts for a distinct kind of amino acid.
When a missense mutation takes place within a DNA, a modification in one of the RNA codon sequences results at the time of transcription. This change in codon will ultimately result in the formation of a different amino acid, which gets presented within a protein at the time of translation. Like in the given case, a change in codon resulted in the substitution of the amino acid tyrosine with an amino acid cysteine.
The correct answer is chloroplast. If an organism has chloroplasts then it will be an autotroph because it will be able to make its own food by the means of photosynthesis. This is common for plants but there are some bacteria that can photosynthesize as well. If you don't have them you have to feed on other organisms that have energy for you.
I think it would be A. Helicase
