Module 2 Section 3 - Polynucleotides And DNA

Question 1

Nucleotides join together to form

Answer 1

Polynucleotides

Question 2

Where do nucleotides join up to make polynucleotide bonds

Answer 2

They join up between the phosphate group of one nucleotide and the sugar of another nucleotide

Question 3

What type of reaction joins nucleotides together to make polynucleotides

Answer 3

Condensation reaction

Question 4

What is the bond called between nucleotides in a polynucleotide

Answer 4

A phosphodiester bond

Question 5

What does the phosphodiester bond consist of

Answer 5

The phosphate group and two ester bonds

Question 6

What is the sugar-phosphate backbone

Answer 6

The chain of sugars and phosphates

Question 7

How are polynucleotides broken down to nucleotides

Answer 7

by breaking the phosphodiester bonds using hydrolysis reaction

Question 8

What do two polynucleotide strands join together to form

Answer 8

A double helix

Question 9

How are DNA polynucleotide strands joined together by

Answer 9

Hydrogen bonding between bases

Question 10

What is complementary base pairing

Answer 10

Each base can only join with one particular partner

Question 11

What does adenine always pair with

Answer 11

Thymine

Question 12

What does cytosine always join with

Answer 12

Guanine

Question 13

A purine always…..

Answer 13

Pairs with a pyrimidine

Question 14

How many hydrogen bonds are formed between A and T

Answer 14

2 hydrogen bonds

Question 15

How many hydrogen bonds form between C and G

Answer 15

3 hydrogen bonds

Question 16

What twists to form the DNA double helix

Answer 16

Two antiparallel polynucleotide strands

Question 17

What does DNA do before cell division

Answer 17

It copies itself

Question 18

What enzyme breaks the hydrogen bonds between the two polynucleotide DNA strands

Answer 18

Helicase

Question 19

What happens to the helix after Helicase breaks hydrogen bonds

Answer 19

The helix unzips to form two single strands

Question 20

What acts as a template for a new strand

Answer 20

Each original single strand

Question 21

What do the free floating DNA nucleotides join to

Answer 21

The exposed bases on each original strand

Question 22

the DNA nucleotides join to the exposed bases on each original template strand by….

Answer 22

Complementary base pairing. A with T, C with G

Question 23

How are nucleotides of the new strand joined together by

Answer 23

The enzyme polymerase

Question 24

What does the DNA polymerase form

Answer 24

Sugar phosphate backbone

Question 25

Why is DNA replication called semi-conservative replication

Answer 25

Because half of the strands in each new DNA molecule are from the original piece of DNA

Question 26

Why does DNA replication need to be accurate

Answer 26

Because it needs to make sure genetic information is conserved each time DNA is replicated

Question 27

What is a mutation

Answer 27

A change to the DNA base sequence

Question 28

How often do mutations occur

Answer 28

Randomly and Spontaneous

Question 29

Do mutations always have an effect

Answer 29

Not always however they can alter the sequence of amino acids in a protein which causes an abnormal protein to be produced which may or may not function better than the normal.