Question

exam lesson name: introduction to biotechnology
exam number: 700795rr
exam guidelines
exam instructions
question 6 of 20 :
select the best answer for the question.

1. which of the following is used to form covalent bonds in the sugar-phosphate backbone between fragments of dna?

a. dna ligase
b. centrifugation
c. restriction enzymes
d. ultrafiltration
mark for review (will be highlighted on the review page)
<< previous question next question >>

Explanation:

To solve this, we analyze each option:

• Option A: DNA ligase is an enzyme that catalyzes the formation of covalent bonds (phosphodiester bonds) in the sugar - phosphate backbone to join DNA fragments, like in processes such as DNA replication (lagging strand) and recombinant DNA technology.
• Option B: Centrifugation is a technique used to separate components of a mixture based on density, not for forming bonds in DNA.
• Option C: Restriction enzymes are used to cut DNA at specific sequences, not to join fragments.
• Option D: Ultrafiltration is a filtration technique for separating substances based on size, not related to DNA bond formation.

Answer:

A. DNA ligase