Question

Read the passage and answer the following question.

Bacterial plasmid sequence: ATCCCA...1000 more nucleotides..... ..ATTAAGGCCTTACAGGACCCCGGAATGAGAGTA ATGGGCTATTCAGGTA... 2000 more nucleotides
Human DNA sequence: ATATCGTAATGTTGGTG..500 more nucleotides.. ..GTGTCAGGACGGGTGAAAGCCAGGACGCCGAATCG...5000 more nucleotides
The underlined DNA signifies the gene of interest were trying to clone Restriction enzyme sequences:
ERA I GTAATG
CRO I CAGGAC
MEM II GCCG
How many bands would show up on a 1 percent agarose gel if the plasmid was cut with both ERA I and CRO I?

• A. 1
• B. 2
• C. 3
• D. 100
• E. 1,000

Answer 1

The correct option is C 3

CRO I has restriction sequence CAGGAC and ERA I has the restriction sequence GTAATG. When both the enzymes are used to cleave the bacterial and the human DNA, there are three fragments produced. So, only three bands will show up on the agarose gel as the restriction enzymes will cut very close. Thus, the correct answer is option C.