Genetics And Evolution

Question 1

Define a mutation

Answer 1

Change in the amount or the structure of DNA of an organism

Question 2

How can a phenotype be passed on?

Answer 2

Through mitosis and meiosis

Question 3

Define somatic mutations

Answer 3

Mutations passed on to daughter cells and inherited

Question 4

Define a gene mutation

Answer 4

Change in nucleotide sequence

Question 5

Define a chromosome mutation

Answer 5

Change in several genes effecting am area on a chromosome. Can be structural changes on DNA

Question 6

What is translocation in mutation?

Answer 6

New / extra genes

Question 7

What is duplication in mutation?

Answer 7

Some genes are copied

Question 8

What is deletion in Mutations?

Answer 8

Some genes are lost

Question 9

What is inversion in mutation?

Answer 9

Genes are removed and rearranged facing backwards

Question 10

What is substitution in point mutation?

Answer 10

One base changes to another

Question 11

What is insertion in point mutation?

Answer 11

Adds a base to sequence causing the sequence to shift

Question 12

What is deletion in point mutation?

Answer 12

Removal if a base causing a change in sequence

Question 13

What is frame shift in Mutations?

Answer 13

Amino acids chain shifts due to insertion

Question 14

What are the 3 results of substitution Mutations?

Answer 14

Coded for the same amino acids

Codes for different amino acids

Codes for a stop codon

Question 15

What are the effects of Mutations?

Answer 15

Phenotype may not be effected
Different R groups change amino acid
Protein can become shorter
Could lead to an advantageous phenotype eg lactose tolerance

Question 16

Name some diseases caused by Mutations

Answer 16

Cystic fibrosis
Sickle cell anaemia

Question 17

Name some beneficial mutations

Answer 17

Lactose tolerance
Bacteria resistance

Question 18

Name some neutral Mutations

Answer 18

Dimples
Free ear lobes

Question 19

Define a mutagen

Answer 19

Biological, chemical or physical factors that cause a mutation

Question 20

Name an example of a mutagen

Answer 20

Ionising UV radiation- break strands of DNA
Viruses- DNA of foreign body may change organisms genome

Question 21

What can chromosome Mutations cause?

Answer 21

Developmental problems

Question 22

When do structural changes to chromosomes occur?

Answer 22

Prophase 1

Question 23

What is gene regulation?

Answer 23

When gene expression makes a gene become active. The expressed gene is then transcribed and translated. Also controls synthesis

Question 24

What are mutation responses caused by in prokaryotes?

Answer 24

Due to changes in the external environment

Question 25

What do multicellular organisms use gene regulation?

Answer 25

To specialise cells

Question 26

What does transcriptional mean?

Answer 26

Controlling if transcription occurs

Question 27

What does post transcriptional mean?

Answer 27

Modifying RNA

Question 28

What does translational mean?

Answer 28

Stopping or starting translation

Question 29

What does post translational mean

Answer 29

Modify proteins after synthesis

Question 30

What are the 2 mechanisms of gene expression?

Answer 30

Chromatin modification Transcription factors

Question 31

Outline chromatin Modification

Answer 31

1. DNA wound round histone proteins firming a chromatin 2. DNA negatively charged, histone positively charged 3. Heterochromatin tightly bound to DNA 4. Euchromatin loosely bound to DNA and is present in interphase

Question 32

What happens if you add an acetyl ir phosphate group to a histone?

Answer 32

Reduces the positive charge so DNA binds loosely

Question 33

What happens when you add a methyl group to a histone?

Answer 33

Makes DNA mire hydrophobic so they bind tightly to each other in tighter coils

Question 34

What happens to transcription if you condense chromatin?

Answer 34

Suppresses transcription

Question 35

What happens to transcription if you decondense chromatin?

Answer 35

Activates transmission

Question 36

Where do transcription factors bind to?

Answer 36

Promoter regions

Question 37

What are transcription factors?

Answer 37

Proteins that control expression of other genes

Question 38

Define an operon

Answer 38

A group of structural genes found in prokaryotes with control elements and a regulatory gene which undergo the same mechanism at the same time

Question 39

Outline how a lac operon works

Answer 39

Recessor protein bids to promoter region. Sucrose then binds to protein changing its shape so it can no longer bind to promoter region so becomes released. RNA polymerase then binds and can form mRNA strands

Question 40

What is a transcription factor?

Answer 40

Protein which turns genes on and off by binding to DNA

Question 41

What is the rate of transcription sped up by?

Answer 41

AMP + CRP

Question 42

When can't AMP + CRP bind together?

Answer 42

If glucose is present

Question 43

What does an exon code for?

Answer 43

Amino acids sequence

Question 44

What is attached at the 5 prime end of DNA?

Answer 44

A cap

Question 45

What is attached at a 3 prime end of DNA?

Answer 45

A tail

Question 46

What aids the binding of proteins to ribosomes?

Answer 46

Initiation factors

Question 47

What does protein kinase do?

Answer 47

Adds phosphate groups to proteins changing their active site

Question 48

What is secondary cell to cell signalling?

Answer 48

When AMP + CRP bind together

Question 49

What is splicing?

Answer 49

When introns are removed which allows DNA to be read. It can cause a new sequence of DNA to form

Question 50

Define body plan

Answer 50

General structure of organisms

Question 51

What is the hox gene?

Answer 51

Gene which codes for homeodomain which contains homebox genes

Question 52

What are homebox genes?

Answer 52

Genes which have changed very little

Question 53

Outline the role of homeodomain

Answer 53

Homeodomain binds to DNA acting as a transcription factor. It binds to DNA to activate or repress proteins responsible for body plan

Question 54

What is apotosis?

Answer 54

Breaks down cells into fragments which are engulfed by phagocytes. The process also removes unwanted structures

Question 55

What is apotosis?

Answer 55

Breaks down cells into fragments which are engulfed by phagocytes. The process also removes unwanted structures