Unit 1.1 DNA and the Genome

Question 1

DNA location

Answer 1

Nucleus

Question 2

DNA scientific name

Answer 2

Deoxyribose nucleic acid

Question 3

Function of DNA

Answer 3

To store the genetic information of genes for protein production

Question 4

Gene definition

Answer 4

A section of DNA which codes for a protein.

Question 5

Nucleotide components

Answer 5

Phosphate
Deoxyribose sugar
base

Question 6

Name of the bond between the phosphate and the sugar

Answer 6

Sugar phosphate bond

Question 7

What type of backbone is in DNA

Answer 7

Sugar phosphate backbone

Question 8

Complimentary base pair rule

Answer 8

A to T
G to C

Question 9

Why are adenine and thymine complimentary

Answer 9

Because they have two hydrogen bonds

Question 10

Why are G and C complimentary

Answer 10

Because they have three hydrogen bonds pulling them together

Question 11

Bond between bases

Answer 11

(Weak and temporary) Hydrogen bonding

Question 12

antiparallel bond definition

Answer 12

Antiparallel bonding means that on one strand the deoxyribose sugar attaches to the phosphate at 5’ carbon position and on the other strand the deoxyribose sugar attaches to the phosphate at the 3’ carbon position, meaning the strands point in different directions giving it the double stranded helix shape

Question 13

How does antiparallel bonding work

Answer 13

The third carbon points upwards on one of the DNA strand and on the other the fifth carbon bond points upwards on the other DNA strand giving a spiralling structure.

Question 14

DNA shape

Answer 14

Double stranded helix

Question 15

Examples of prokaryotic cells

Answer 15

Bacteria cells

Question 16

Examples of eukaryotic cells

Answer 16

Plant, animal and fungal cells.

Question 17

Prokaryotes features

Answer 17

No membrane bound nucleus,
Circular DNA and chromosome
Contain plasmids

Question 18

Features of eukaryotic cells

Answer 18

They have a membrane bound nucleus
Their chromosomes are linear
They contain histones
Their mitochondria and chloroplasts have circular DNA

Question 19

Histones definition

Answer 19

Proteins which DNA coil around in eukaryotic cells

Question 20

DNA replication definition

Answer 20

Where DNA makes an identical copy of itself for mitosis.

Question 21

Stage 1 of DNA replication

Answer 21

The DNA parental strand unwinds from a double stranded helix into a linear strand.

Question 21

Stage 1 of DNA replication

Answer 21

The DNA parental strand unwinds from a double stranded helix into a linear strand.

Question 22

Stage 2 of DNA replication

Answer 22

The weak and temporary hydrogen bonds between the bases break down between strands.

Question 23

Stage 3 of DNA replication

Answer 23

Two template strands are formed.

Question 24

Stage 4 of DNA replication

Answer 24

Primers attach onto the 3’ end of the template strands and DNA nucleotides attach on template strand in a 5-3 direction (new strand) by the enzyme DNA polymerase . On the leading strand nucleotides are added continuously whereas on the lagging strand DNA they are added discontinuously with multiple primers attaching on due to nucleotides being added in the direction away from the DNA fork.

Question 25

Stage 5 of DNA replication

Answer 25

DNA polymerase is used to bond the sugar phosphate backbone together on both strands and DNA ligase bonds the fragments of DNA on the lagging strand

Question 26

Stage 6 of DNA replication

Answer 26

The 2 identical DNA strands will then rewind into their double stranded helix shape and DNA replication has been completed.

Question 27

Required materials of DNA replication

Answer 27

DNA strand
DNA polymerase and DNA ligase
ATP
Primers and free nucleotides

Question 28

Why does DNA replication happen

Answer 28

To ensure that daughter cells have the same genetic information as mother cells in mitosis.

Question 29

PCR stands for

Answer 29

Polymerase chain reaction

Question 30

PCR uses

Answer 30

Forensics in crime scenes
Paternal lawsuits
Diagnosing genetic disorders.
Amplifying DNA

Question 31

PCR stage one

Answer 31

Denaturing
DNA is heated at 92 to 98 degrees Celsius to break apart the hydrogen bonds between the bases and form 2 template strands.

Question 32

Stage 2 of PCR

Answer 32

Annealing
The DNA is cooled to 50 to 65 degrees Celsius and the primers attach onto the template strands at the 3’ end.

Question 33

Stage 3 of PCR

Answer 33

Extension
The DNA is then heated back up to 70 - 80 degrees Celsius to allow for the DNA polymerase to work in optimum conditions and attach to free nucleotides to the template strands.

Question 34

Necessary materials for PCR

Answer 34

Strand of DNA
free nucleotides
Specific primers
Heat resistant DNA polymerase

Question 35

Gel electrophoresis

Answer 35

The process of separating DNA fragments based on molecular size using electricity.

Question 36

Uses of Gel Electrophoresis

Answer 36

Diagnosing genetic disorders
Crime scene forensics
Paternity lawsuits and ancestry

Question 37

Stages of Gel electrophoresis

Answer 37

Load DNA
Apply current
Analyse gel

Question 38

Primers

Answer 38

Molecules made up of DNA nucleotides which attach onto the 3’ end of template strands and provide a starting point for the free nucleotides to bond onto the template strand.

Question 39

DNA polymerase

Answer 39

An enzyme which fuses together the sugar phosphate backbone of DNA

Question 40

DNA ligase

Answer 40

An enzyme which fuses the fragments of DNA of the lagging strand together.