Answer:
b. Forward or reverse primers
Explanation:
Sanger sequencing is a technique of DNA sequencing based on the extension of DNA fragments with variable sizes terminated with dideoxynucleotides at the 3′ end. This technique was developed by Frederick Sanger in 1977. In Sanger sequencing, a short primer is added in order to bind by complementarity to the target DNA region of interest. Subsequently, a DNA polymerase adds nucleotides (A, T, C and G) in the 5'-3' direction. Finally, the extension of the DNA strand is stopped by adding dideoxynucleotides, which are nucleotide analogs (i.e., modified nucleotides) that act as DNA synthesis terminators.
The Griffith's experiment, the Avery-MacLeod-McCarty experiment, and the Hershey–Chase experiments were the set of experiments that established DNA as the key hereditary molecule. The Avery-MacLeod-McCarty experiment was an extension to the Griffith's experiment. The heat killed virulent S strain cells of the Griffith's experiment were lysed to form a supernatant containing a mix of RNA, DNA, proteins and lipids from the cell. The supernatent was equally divided into 3 parts after the removal of the lipids. The 3 parts were respectively treated with an RNAase to degrade the RNA, DNAase to degrade the DNA and proteinase to degrade the proteins. The treated supernatant was then added into the culture containing the non-virulent R cells. In case of the supernatant treated with the DNAse, no transformation of R cells into S cells occurred. The transformation of R cells to S cells occurred in the proteinase and the RNAse cases. This indicated that DNA was the hereditary molecule and not protein or RNA.

Answer:
Prokaryotes do not have a nucleus; eukaryotes have a nucleus
Explanation: