Genomic mammalian DNA cannot be expressed directly using bacterial expression vectors because mammalian genomic DNA contains introns, which the bacterial cell cannot excise. Complementary DNA, or cDNA, enables scientists to express mammalian DNA from a bacterial plasmid.

Steps involved in cDNA synthesis (Reverse Transcription)

Explanation:

1. Mature mammalian mRNA is isolated and used as a template

2. Enzyme Reverse transcriptase binds to the mRNA Template provided with the help of a primer, then  synthesizes a  first strand of cDNA without introns

3. The original mRNA template is hydrolyzed by raising the pH

4. To make a double strand DNA, A primer site is created on the single-stranded cDNA (first strand)

5. DNA polymerase synthesizes a new strand that is complementary to the first cDNA strand, forming a double-stranded cDNA molecule

answer; i believe the correct answer is ( proteins );

the dna of humans and mice is almost 92% similar. this similarity indicates that . mice have a tail, while humans have a tailbone. the tailbone is a structure in humans.yes it's true.