DNA 1 - MT2 - Part 1

Question 1

What are DNA markers?

Answer 1

They are specific DNA sequences that can be used to identify individual people or characterize human populations

Question 2

What are DNA markers used for? (3)

Answer 2

1. Identify individual people
2. Characterize human populations
3. Identify and study non human species

Question 3

What does the sequence of DNA refer to?

Answer 3

The order of DNA bases

- pairing is specific

Question 4

What does Adenine base bind to?

Answer 4

Thymine

Question 5

What does Guanine base bind to?

Answer 5

Cytosine

Question 6

What are A, G, T and C known as?

Answer 6

Nucleic acids

Question 7

What is DNA’s structure?

Answer 7

A double helix

Question 8

Is DNA inherited?

Answer 8

Yes

- it gets passed on from generation to generation with high stability

Question 9

When does DNA change?

Answer 9

When it gets mutated

- occurs rarely

Question 10

What does DNA left at a crime scene imply?

Answer 10

The presence of a specific person at the crime scene

Question 11

What is an example of a type of DNA left at the crime scene?

Answer 11

DNA fingerprints

Question 12

How can DNA be used? (5)

Answer 12

1. In a criminal case
2. In determining parentage
3. Use of DNA markers in tracking migrations of people
4. In determining ancestry
5. Markers and disease susceptibility

Question 13

What can blood types be used for?

Answer 13

Determine parentage

- but not prove it (only can help)

Question 14

How does a DNA marker track migrations of people?

Answer 14

The marker might spread through a human group after it has branched off from other human groups
- looking for specific characteristics in certain human groups

Question 15

How does a DNA marker detect disease susceptibility?

Answer 15

The DNA marker can be within or close to disease genes and can signal the presence of those disease genes in someones genome

Question 16

Polymer

Answer 16

A large molecule built from many smaller units (monomers) of a similar form

Question 17

What is an example of a polymer?

Answer 17

DNA

Question 18

What are monomers of DNA called?

Answer 18

nucleotides

Question 19

What makes up a nucleotide? (3)

Answer 19

1. Phosphate groups
2. A sugar
3. Nitrogenous bases

Question 20

What is DNA strands orientation?

Answer 20

5’–>3’ and 3’–> 5’

• anti parallel
• has polarity

Question 21

What does 5’ refer to?

Answer 21

How the carbons are numbered in one of the sugars

Question 22

Is there polarity between the base sequences?

Answer 22

No

Question 23

What 2 nucleic acids consists in a purine?

Answer 23

1. A

2. G

Question 24

What 2 nucleic acids consists in a pyrimidine?

Answer 24

1. C

2. T

Question 25

What order are strands made in?

Answer 25

5’ to 3’ direction

Question 26

What happens if there are some miss pairings in the DNA strand?

Answer 26

It can de-stabilize it

- could possible fall apart

Question 27

What type of bond are between the base pairs?

Answer 27

H bonding

Question 28

H bonding (3)

Answer 28

1. Weak bonds between bases
2. Form and break very easily
3. Easily disrupted

Question 29

Why are DNA strands complementary?

Answer 29

Because of the base pairing

Question 30

What shape is the most stable conformation and why? (2)

Answer 30

1. Helical shape

2. Because it is in its lowest energy

Question 31

DNA denaturing

Answer 31

Is when the DNA strands are heated up and they start to unwind and the bonds holding them together are no longer there and the strands separate

• once cooled they can re-form
• but you need a collision to do this

Question 32

Polyelectrolyte theory of a gene

Answer 32

Says that the negative charges on the two backbones of the DNA molecule spread it out, giving easier access to the machinery that reads and copies the base sequence

Question 33

What does the negative charge do on the DNA strands?

Answer 33

Repels each other

Question 34

What groups have the negative charge?

Answer 34

Phosphate groups