Question

which best describes how scientists found the human gene that make insulin? a. they worked backwards from mrna to dna. b. they used the base sequence to find the amino acid sequence. c. they found insulin - producing genes in bacteria. d. they cloned insulin proteins using pcr.

Explanation:

Scientists found the human insulin - producing gene by working backwards from mRNA to DNA. mRNA is transcribed from the DNA gene. By starting with the mRNA that codes for insulin (isolated from insulin - producing cells), they could use reverse transcriptase to make a DNA copy (cDNA) of the mRNA. This cDNA represents the coding sequence of the insulin gene.

Answer:

A. They worked backwards from mRNA to DNA.