DNA Sequencing

Question 1

What is DNA sequencing?

Answer 1

Is the determination of the precise order of nucleotides in a sample of DNA.

Question 2

What is the most commonly used method of DNA sequencing?

Answer 2

The Sanger method.

Question 3

What is the ‘more’ correct naming of nucleotides?

Answer 3

Deoxynucleotide triphosphates or DNTPs.

Question 4

Why are nucleotides called deoxynucleotides?

Answer 4

Because they consist of 3 phosphate groups joined to the sugar deoxyribose with its base.

Question 5

What occurs when DNA forms?

Answer 5

1. Each nucleotide loses 2 phosphate groups.
2. The sugar molecule loses a hydrogen atom from the hydroxy group (OH) when it bonds to the phosphate group of an adjacent nucleotide.

Question 6

In the Sangers method, what is added?

Answer 6

Synthetic nucleotides that lack the OH group.

Question 7

What are these synthetic nucleotides called?

Answer 7

Dideoxyribonucleotides or ddNTPs.

Question 8

What are Dideoxyribonucleotides?

Answer 8

Are a modified deoxyribonucleotide that lacks a hydroxyl group of the sugar component.

Question 9

What is the purpose of these Dideoxyribonucleotides or synthetic nucleotides?

Answer 9

They stop the elongation of the sequence because there is no OH for the next nucleotide to attach to. This happens at each of the nucleotides in the DNA sample, creating different lengths of DNA.

Question 10

What are the 4 uses of DNA sequencing?

Answer 10

1. To identify mutations or to compare DNA from different organisms.
2. Identifying inherited disorders such as Cystic Fibrosis or Sickle Cell anemia.
3. Maternity and paternity tests in cases where the identity of the father or mother of a child was in dispute.
4. To compare species in order to track evolutionary changes.

Question 11

List the 4 ethical considerations with genetic information.

Answer 11

1. Autonomy.
2. Confidentiality.
3. Equity.
4. Privacy.

Question 12

Describe autonomy as an ethical consideration.

Answer 12

Respect for the right to be self-determining and to choose whether or not to be tested and if tested, to know and share the information.

Question 13

Describe confidentiality as an ethical consideration.

Answer 13

The use of genetic information is treated with sensitivity and is accessed only by those who are authorised to access it.

Question 14

Describe equity as an ethical consideration.

Answer 14

The right to fair and equal treatment regardless of genetic information.

Question 15

Describe privacy as an ethical consideration.

Answer 15

The right to be left alone and to make decisions regarding genetic testing and the resulting information, independent of others.