Module 6: Genetics Evolution and Ecosystems

Question 1

What is Mutation?

Answer 1

Mutation is a change to nucleotides of DNA which could result in the formation of a non-functional protein.

Question 2

What is Gene Mutation?

Answer 2

Gene mutation is a change to DNA base sequence.

Question 3

What are more likely to cause mutations?

Answer 3

Mutagenic Agents: These work by intefering with DNA replicaion during transcription e.g
-High energy radiation (UV light),
-Ionizing radiation (Gamma rays and X rays)
-Chemicals (carcinogens such as mustard gas and cigarette smoke).

Question 4

What is an operon?

Answer 4

A cluster of genes under the control of a promoter.

Question 5

What structural detail of a polypeptide is altered by gene mutations.

Answer 5

– The sequence of amino acids/ primary structure

Question 6

What is a frameshift?

Answer 6

Frameshift is the addition or deletion of a base resulting in the subsequent codons to be altered.

Question 7

Original:TAC TTC AGG TGG

Mutation:TAC TCA GGT GG

What type of mutation is this?

Answer 7

Deletion

Question 8

Original:TAC TTC AGG TGG

Mutation:TAC ATT CAG GTG G

What type of mutation is this?

Answer 8

Addition

Question 9

Original:TAC TTC AGG TGG

Mutation:TAC ATC AGG TGG

What type of mutation is this?

Answer 9

Substitution

Question 10

What do transcription factors do?

Answer 10

Transcription factors control the expression of genes by controlling which gene is turned on or off during transcription.

Question 11

What mechanism controls production of lactase ?

Answer 11

Lac operon.

Question 12

How it is possible for a mutation to have no effect on the protein produced from that gene

Answer 12

– If the mutation occurs in the intron
– More than one codon codes for an amino acid/the genetic code is degenerate
– Some amino acids won’t alter the shape of the protein

Question 13

What are the 3 types of point mutations?

Answer 13

– Substitution
– Insertion
– Deletion

Question 14

What does the statement “the genetic code is degenerate” mean?

Answer 14

This means that more than one codon can code for an amino acid so point(substitution) mutations may have no effect and a nrmal functioning protein can still be made

Question 15

What is a nonsense mutation?

Answer 15

This is when the protein that is being coded for is abruptly put to a stop so the polypeptide is no longer coded for.

Question 16

What is a promoter

Answer 16

This is a DNA sequence where RNA polymerase binds to

Question 17

What is an Operator?

Answer 17

This a DNA sequence where the repressor protein binds to

Question 18

What are Introns?

Answer 18

Inrons are sections of DNA that do not code for a protein

Question 19

What is decomposition?

Answer 19

Decomposition is the break down of dead organic matter by bacteria (saprobionts)

Question 20

What is nitrogen fixation?

Answer 20

Nitrogen fixation is when nitrogen in the air is converted into nitrogen in plants by the bacteria- rhizobium and azobacter.

Question 21

What is nitrification?

Answer 21

Nitrification is when ammonia in plants are converted into nitrites by nitrozomas and then into nitrates by nitrobacters

Question 22

What is denitrification?

Answer 22

Denitrification is when ammonium ion (nitrates) are turned into nitrogen in the air by denitrifying bacteria

Question 23

What is a climax comunity?

Answer 23

A climax community is the dominant species formed after the pioneer species have died.

Question 24

What is a pioneer community?

Answer 24

A species that arrive before the climax community hence they have less biodiversity.

Question 25

How is an allele spread thoughout the population?

Answer 25

-- Variation occurs within the popuation -- Organisms with alleles which give them characteristics most suited to their environment are more likely to survive and reproduce to give a fertile offspring. Hence, they can pass on the advantageous allele. -- Selection pressure occurs so overtime, the frequency of the advantageous allele increases in the population

Question 26

What is likely to cause variation within a population?

Answer 26

Mutation

Question 27

What can result in the formation of a new species?

Answer 27

Gene mutation. Selection pressure. A change in the environment.

Question 28

What are the advantages of using immobilised enzymes?

Answer 28

-- Enzymes can be reused -- Enzymes remain active over a wider range of temperature -- The product is not contaminated by enzymes

Question 29

What chemical is produced by plants in response to attack by pathogens?

Answer 29

-- Callose

Question 30

Whatare the properties of cellulose?

Answer 30

-- High tensile strength -- Inflexible -- Insoluble in water

Question 31

Steps of gel electrophoreis...

Answer 31

-- Load the samples unto the agarose gel -- Apply voltage for a set time -- Stain the gel -- Photograph the gel

Question 32

What precautions should be taken when preparing a bacterial culture in order to ensure that the procedure is aeseptic?

Answer 32

-- Pass the bacterial culture bottle over flame -- Do not set the lid of the bacterial culture bottle on the sterilised surface -- Wash hands -- Wear gloves -- Use sterile equipment -- Disinfect surfaces -- Use a bunsen to create an upwards air flow

Question 33

What are the precautions that should be taken when preparing a bacterial culture in order to ensure the procedure is aeseptic?

Answer 33

-- Pass the bottle of the bacterial culture over flame -- Do not set the lid of the bacterial culture on the sterilised surface -- Was your hands -- Sterilise surface -- Use sterile equipment -- Disinfect surfaces -- Have a bunsen flame to create an upwards air flow

Question 34

what are some advantages of using microorganimsms in the production of food?

Answer 34

-- No ethical issues -- Rapid growth -- Non-seasonal -- Suitable for vegeterians -- Takes up little space -- Low costs because they work at low temperatures

Question 35

Why is a cooling system necessary during fermentation?

Answer 35

-- It prevents the enzymes from denaturing -- It inibits the growth of pathogenic bacteria

Question 36

What is a method that can be used to determine the concentration of protein in a solution?

Answer 36

Biosensor

Question 37

What is the name of the gene responsible for controlling body plan in multicellular organisms?

Answer 37

Homeobox gene

Question 38

Outline how to use a colorimeter to determine the concentration of protein in a solution

Answer 38

-- Zero the colorimeter -- Use known concentrations of protein solutions -- Plot a calibration curve -- Measure the absorbance of the unknown sample -- Compare with the calibration graph

Question 39

What is species eveness?

Answer 39

The relative abundance of each species in an area.

Question 40

Suggest a reason other than epistasis on why the phenotypic ratio might not be 9:3:3:1?

Answer 40

-- Sex linkage -- Both genes are on the same chromosome

Question 41

What ia an allele?

Answer 41

-- An allele is a different version of a gene

Question 42

What is a genotype?

Answer 42

The alleles an organism has

Question 43

What is a phenotype?

Answer 43

-- A characteristic an allele produces