Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Year 13 BIOLOGY consolidation > 3.8.2 Gene expression and cancer > Flashcards

3.8.2 Gene expression and cancer Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Totipotent stem cells are able to differentiate into..

A

any type of body cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

multicellular organisms are made up from…

A

many different types of specialised cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

specialised cells originated from..

A

stem cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

unspecialised cells that can develop into other cell types are called

A

stem cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Two main sources of stem cells can be found..

A

in the embryo, adult tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

these types of stem cells are only present in mammals in the first few divisions of the embryo

A

totipotent (very early embryo)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

these types of stem cells are still found in the embryo but have lost their ability to develop into differentiate into placental cells

A

pluripotent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

adult stem cells can be one of two types

A
  1. multipotent stem cells

2. unipotent stem cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

these types of stem cells can differentiate into a limited number of stem cells e.g. bone marrow cells can form RBC and WBC

A

multipotent stem cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

These types of stem cells can only differentiate into ONE type of cell

A

unipotent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Stem cells specialise because…

A

different genes are expressed (turned off and on)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

All cells contain the same DNA - true or false?

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Stem cells all contain the same genes - true or false?

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Molecules which regulate the expression of genes are called..

A

transcription factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where do transcription factors bind to regulate gene expression?

A

upstream of the gene (promoter region)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What do transcription factors do to regulate gene expression?

A

encourage binding of RNA polymerase (turn on genes) or prevent RNA polymerase binding (turn off genes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where are transcription factors found?

A

nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When a cell receives a signal to express a gene what does the transcription factor do?

A

moves from the cytoplasm to the nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Specialised cells all look different - why?

A

they all express different genes and thus proteins - this determines the cells overall structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Which stem cell can red blood cells originate from?

A

bone marrow stem cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Transcription is when

A

DNA is copied into mRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Translation is when

A

mRNA is translated into a sequence of amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what are cardiomyocytes?

A

heart cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what can stem cells be used for?

A

treat diseases e.g. paralysis - replace damaged cells/tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

benefits of using stem cells in medicine?

A

save life and improve quality of life for many people

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

iPS cells stands for?

A

induced pluripotent stem cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are iPS cells?

A

created in the lab - reprogramming adult stem cells to become pluripotent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the limitations with adult stem cells?

A

limited differentiation capacity - they are mulitpotent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Where do we source embryonic stem cells from?

A

embryos created in the lab from IVF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Embryonic stem cells are classified as one of twp types

A
  1. totipotent (very early embryo)

2. pluripotent (early embryo)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Issue surrounding embryonic stem cells?

A
  1. ethics surrounding the sourcing of the embryos (embryo will be destroyed)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

In all cells which genes will be permanently expressed?

A

genes involved in respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

All organisms develop from a fertilised egg - what is the scientific name for this?

A

zygote

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Zygotes divide by what process?

A

Mitosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Can specialised cells change into other cell types?

A

animals - no

plants - yes - shoots/roots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Name a hormone that can regulate transcription

A

oestrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What type of hormone is oestrogen?

A

steroid hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How can oestrogen enter the cell?

A

lipid soluble and diffused through the phospholipid bilayer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What does oestrogen bind to to regulate transcription?

A

a binding site/receptor site on the transcription factor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

When oestrogen binds to the receptor on the transcription factor what happens?

A

The DNA binding site on the transcription factor is now able to bind to DNA (transcription activated)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Why is oestrogen able to bind the receptor on transcrption factor?

A

oestrogen has a complementary shape the the receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What property of oestrogen allows it to diffuse through the phospholipid bilayer?

A

lipid soluble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Who proposed the structure of DNA?

A

Watson and Crick

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is meant by epigenetics?

A

heritable changes in gene function without change the base sequence of DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What sort of environmental factors might influence phenotype?

A

stress, sunlight, chemical exposure, diet,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

How is your DNA organised into chromosomes?

A

DNA wrapped around proteins called histones (forming chromatin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

DNA and histones are covered in chemicals known as ..

A

tags

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Tags attached to the DNA and histones form a second layer known as..

A

the epigenome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What determines the shape of the DNA and histone complex?

A

epigenome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

DNA that is tightly packed, preventing transcription factors binding leads to

A

gene silencing

51
Q

DNA that is loosely packed, allowing transcription factors to access the DNA leads to…

A

gene activation/expression

52
Q

DNA code is fixed but your epigenome is…

A

flexible

53
Q

What does your epigenome respond to?

A

the environment

54
Q

Tags attached to DNA are knowns as

A

methylation

55
Q

Tags attached to histones are knowns as

A

actylation

56
Q

When the association of DNA and histones is weak what does this mean for gene expression?

A

transcription factors can access the DNA and turn ON a gene

57
Q

Tight association of DNA and histones affects gene expression - how?

A

prevents transcription factors binding to the DNA so turns OFF gene expression

58
Q

tight association of DNA and histones is brought about by..

A

decreased acteylation and increased methylation

59
Q

loose association of DNA and histones is brought about by..

A

increased acteylation and decreased methylation

60
Q

What does decreased acetylation do to the histone proteins?

A

increased + charge so more strongly attracted to phosphate in DNA

61
Q

Why does methylation prevent transcription?

A
  1. prevents transcription factors binding to DNA

2. attracts proteins that would condense DNA

62
Q

increased gene expression is brought about by

A

more acetylation and less methylation

63
Q

reduced gene expression is brought about by

A

less acetylation and more methylation

64
Q

acetyl group binds to

A

histones

65
Q

methyl group binds to

A

DNA

66
Q

more acetylation EQUALS

A

increased gene expression/DNA loosely packed

67
Q

MORE methylation EQUALS

A

reduced gene expression/DNA tightly packed

68
Q

LESS acetylation EQUALS

A

reduced gene expression/DNA tightly packed

69
Q

LESS methylation EQUALS

A

increased gene expression/DNA loosely packed

70
Q

epigenetics has been associated with what type of disease

A

cancer

71
Q

do epigenetic changes alter the DNA base sequence?

A

NO

72
Q

Preventing gene expression can also be done at the level of mRNA - how?

A

mRNA is cut up to prevent it being translated

73
Q

what type of molecule is involved in silencing mRNA?

A

siRNA

74
Q

Once siRNA is formed what does it associate with?

A

an enzyme

75
Q

What is unique about the siRNA and the mRNA it is going to silence?

A

Their base sequences are complementary

76
Q

enzymes can remove acetyl groups - how would this affect transcription?

A

less acetylation - reduced gene expression (mRNA not transcribed)

77
Q

enzymes can remove acetyl groups - how would this affect DNA-histone complex?

A

tightly packed

78
Q

All tumours are cancerous - true or false?

A

false

79
Q

what is a tumour?

A

mass of cell caused by uncontrolled cell division

80
Q

cancer is…?

A

abnormal mass of cells that invades neighbouring tissues or can break away forming secondary tumours

81
Q

two types of tumours are?

A

benign and malignant

82
Q

Which tumour is cancerous?

A

malignant

83
Q

which tumour does not invade neighbouring cells?

A

benign

84
Q

How do cancers spread?

A

blood stream or via lymphatic system

85
Q

name the two genes that control cell division

A

proto-oncogenes and tumour suppressor genes

86
Q

What is the function of a proto-oncogene?

A

stimulate cell division

87
Q

what is the function of a tumour suppressor gene?

A

slow down cell division

88
Q

what would happen if there was a mutation in a proto-oncogene?

A

turn into oncogene - uncontrolled cell division

89
Q

what would happen if there was a mutation in a tumour suppressor gene?

A

uncontrolled cell division

90
Q

Mutations in genes that control cell division cause…

A

cancer

91
Q

Which type of tumour grows more slowly?

A

benign

92
Q

How might tumour cells look compared to normal cells?

A

different shape
larger/darker nucleus
divide more rapidly

93
Q

what does methylation do to the DNA?

A

adds a methyl group to it

94
Q

In a proto-oncogene what happens to the methylation of the DNA to turn it into a oncogene?

A

hypomethylation (reduced methylation)

95
Q

In a tumour suppressor gene what happens to the methylation of the DNA to cause cells to divide out of control?

A

hypermethylation (increase methylation) - turn gene off

96
Q

which type of tumour grows rapidly?

A

malignant

97
Q

which type of tumour involves using radiotherapy as well as surgery?

A

malignant

98
Q

Which type of tumour remains compact

A

benign

99
Q

which type of tumour grows finger like projections into surrounding tissue?

A

malignant

100
Q

which type of tumour has a capsule?

A

benign

101
Q

what are oncogenes?

A

mutated pro-oncogenes

102
Q

How to proto-oncogenes stimulate cell growth?

A

growth factor binds to receptor stimulating cell division

103
Q

An oncogene can become permanently activated for one of two reasons?

A
  1. oncogene codes for a receptor that is permanently activated
  2. oncogene codes for excessive growth factor
104
Q

How do tumour suppressor genes work?

A

they slow down cell division, repair DNA or tell cells to die

105
Q

what does apoptosis mean?

A

programmed cell death

106
Q

Which gene regulates cell division and prevents formation of tumours?

A

TSG

107
Q

if a TSG is mutated what is the consequence?

A

stops inhibiting cell division and cells divide out of control

108
Q

some cancers are inherited others are…

A

aquired

109
Q

what does the TP53 gene code for?

A

p53 protein

110
Q

why is p53 important?

A

p53 protein is important in apoptosis

111
Q

A mutation in the TP53 will lead to…?

A

inactive p53 protein and no apoptosis, damaged cells continue to divide

112
Q

mutation in a proto-oncogene leads to

A

oncogenes being activated - uncontrolled cell division

113
Q

mutation in a TSG leads to

A

TSG being inactivated - uncontrolled cell division

114
Q

abnormal methylation is common in many tumours - what effect can this have on a TSG?

A

hypermethylation of a TSG - inactivity - uncontrolled cell division (p53 not made)

115
Q

what is hypermethylation?

A

addition on methyl groups on DNA - switching off gene expression

116
Q

transcription of genes is controlled by protein molecules called?

A

transcription factors

117
Q

How do transcription factors move?

A

from the cytoplasm to the nucleus

118
Q

Expression of genes can be affected by other molecules e.g. hormones e.g. ….

A

oestrogen

119
Q

can epigenetic changes be inherited?

A

yes!

120
Q

How would methylation of a TSG lead to cancer?

A
  1. Methylation prevents transcription of gene;turns off gene expression
  2. Protein (p53) not produced that prevents cell division/ causes cell death/apoptosis;
  3. No control of mitosis; uncontrolled cell growth due to mitosis
121
Q

Which cancer gene would be inhibited due to increased methylation?

A

tumour suppressor gene (TSG) - gene not transcribed!

122
Q

give one way benign tumours differ from malignant tumours

A

Cells of benign tumours cannot spread to other parts of the body/metastasise
OR
Cells of benign tumours cannot invade neighbouring tissues;

123
Q

Describe how alterations to TSG can lead to development of tumours

A
  1. increased methylation of TSG
  2. mutations in TSG
  3. TSG not expressed
  4. Leading to rapid uncontrolled cell division

Year 13 BIOLOGY consolidation (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions