Question 1

Which of the following best describes the natural function of restriction enzymes in bacteria?

Accepted Answer

To destroy invading DNA, such as that from viruses

Question 2

A restriction enzyme recognizes the sequence $$5'	ext{GAATTC}3'$$ and cuts between G and A. What type of ends does this produce?

Accepted Answer

Sticky ends

Question 3

Which characteristic is true of a restriction site recognized by restriction enzymes?

Accepted Answer

It is a palindromic sequence, typically 4 or 6 base pairs long

Question 4

Why do scientists use the same restriction enzyme to cut both the donor and recipient DNA when combining genes from two organisms?

Accepted Answer

To ensure the DNA fragments have complementary sticky ends that can rejoin

Question 5

Which of the following is a correct description of the process of gel electrophoresis?

Accepted Answer

DNA fragments are separated based on their size as they move through a gel in an electric field

Question 6

During gel electrophoresis, why do shorter DNA fragments move further through the gel than longer fragments?

Accepted Answer

Shorter fragments can move more easily through the gel matrix

Question 7

A scientist wants to remove a defective gene and replace it with a functional one. Which tool should they use to cut out the defective gene?

Accepted Answer

Restriction enzyme

Question 8

In a crime scene investigation, DNA from the scene and from suspects is cut with the same restriction enzymes and run on a gel. What result would indicate a match between a suspect and the crime scene DNA?

Accepted Answer

The suspect's DNA fragments form bands that match the pattern of the crime scene DNA

Question 9

Which of the following best explains why DNA moves toward the positive pole during gel electrophoresis?

Accepted Answer

DNA is negatively charged

Question 10

A restriction enzyme cuts DNA at the sequence $$5'	ext{CCCGGG}3'. $$After cutting, the fragments have no overhanging bases. What is this type of end called?

Accepted Answer

Blunt end

Question 11

Which of the following is a real-world application of gel electrophoresis?

Accepted Answer

Identifying suspects in a criminal investigation by comparing DNA band patterns

Question 12

If a DNA fragment is 200 base pairs long and another is 800 base pairs long, which will travel further in a gel electrophoresis experiment and why?

Accepted Answer

The 200 base pair fragment, because shorter fragments move faster through the gel

Question 13

Which enzyme is used to join together DNA fragments with complementary sticky ends?

Accepted Answer

Ligase

Question 14

A palindromic DNA sequence is important for restriction enzymes because:

Accepted Answer

It allows the enzyme to cut both strands at the same position

Question 15

Which of the following steps is NOT part of the gel electrophoresis process?

Accepted Answer

Heating the gel to denature the DNA

Question 16

If you want to test paternity using DNA, which combination of biotechnology tools would you use?

Accepted Answer

Restriction enzymes and gel electrophoresis

Question 17

Which of the following best explains why restriction enzymes are essential for genetic engineering?

Accepted Answer

They cut DNA at specific sites, allowing scientists to insert or remove genes

Question 18

A scientist cuts DNA from two different organisms with the same restriction enzyme and mixes the fragments. What is the most likely outcome?

Accepted Answer

The fragments with complementary sticky ends will join together

Question 19

Which of the following is a reason why everyone's DNA produces a unique pattern of bands in gel electrophoresis?

Accepted Answer

Restriction enzymes cut at different sites in different people's DNA due to sequence variation

Question 20

Which of the following best describes a 'sticky end' produced by a restriction enzyme?

Accepted Answer

A single-stranded overhang that can base pair with a complementary sequence

Biotechnology Tools: Restriction Enzymes and Gel Electrophoresis

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