Unit 1 - DNA & The Genome Flashcards
(140 cards)
1
Q
what is the subunit of DNA
A
nucleotide
2
Q
What sugar is found in a DNA nucleotide
A
deoxyribose
3
Q
To which carbon (number) is the base attached
A
1
4
Q
To which carbon (number) is the phosphate attached
A
5
5
Q
To which carbon (number) is the phosphate on the next nucleotide attached
A
3
6
Q
name the structure DNA forms
A
double stranded, double helix
7
Q
what describes the strands in DNA
A
anti-parallel
8
Q
name all 4 bases in DNA
A
Adenine, Thymine, Guanine, Cytosine
9
Q
Give the complementary base pairing in DNA
A
A to T and G to C
10
Q
what type of bond connects complementary base pairs
A
Hydrogen
11
Q
what type of bond connects sugars to phosphates in DNA
A
(strong) covalent
12
Q
The repeating sugar - phosphate structure is called the..
A
backbone
13
Q
what cell type contains a membrane bound nucleus
A
eukaryote
14
Q
what cell type lacks a nucleus
A
prokaryote
15
Q
what DNA structures does a prokaryote contain
A
single circular chromosome and plasmids
16
Q
what organelles contain DNA
A
nucleus, chloroplast, mitochondria
17
Q
what form are the chromosomes in, in eukaryotic cells
A
linear
18
Q
what form do the chromosomes take in chloroplast and mitochondria
A
circular
19
Q
Name the proteins which eukaryotic chromsomes are associated with
A
histones
20
Q
what is the charge on DNA strands
A
negative
21
Q
what is the charge on histones
A
positive
22
Q
why is yeast considered a ‘special’ form of eukaryote
A
it contains plasmids
23
Q
what enzyme extends the strand in DNA replication
A
DNA polymerase
24
Q
what enzyme joins together fragments on the lagging strand
A
ligase
25
what end of the DNA can DNA polymerase synthesise in a continuous strand
Adds to the 3' end / Reads from 5'
26
what are the 2 strands called during DNA replication
leading and lagging
27
what is required to bind to the DNA strand for DNA polymerase to bind
primers
28
what are the primers made of in DNA replication
RNA
29
what enzyme untwists and 'unzips' the DNA during replication
helicase
30
List the 5 requirements for DNA replication
ATP, free DNA nucleotides, enzymes (helicase, ligase and DNA polymerase), Parental/Template DNA strand, primers
31
what is the name for the form of replication used by DNA
semi-conservative (replication)
32
what is the name of the structure formed where helicase breaks the bases
replication fork
33
what bonds break during DNA replication
Hydrogen bonds (between the complementary base pairs)
34
what does PCR stand for
Polymerase Chain Reaction
35
what is the purpose of PCR
to amplify a specific sequence of DNA
36
what is the purpose of primers in PCR
to bracket the required sequence
37
what is unusual about the DNA polymerase used in PCR
it is heat tolerant
38
what temperature does DNA denature at in PCR
92-98oC
39
what happens at 92-98oC
DNA denatures/DNA strands separate
40
what temperature do primers anneal at in PCR
50-65oC
41
what happens at 50-65oC in PCR
primers anneal
42
what temperature is the DNA strand extended at in PCR
70-80oC
43
what happens at 70-80oC in PCR
DNA strand is extended
44
what techinique can be used to separate different sizes of DNA fragment
gel electrophoresis
45
name 3 things that PCR can be used for
forensic investigations, paternity suits, testing for genetic disorders, (Covid-19 testing)
46
what 2 processes are involved in gene expression
transcription and translation
47
the pattern of gene expression determines what in an individual
phenotype
48
as well as genotype, what else impacts on an individuals phenotype
environmental factors
49
modifications to DNA which do not change the sequence are what type of change
epigenetic
50
all of the alleles present defines the …
genotype
51
different forms of gene are called
alleles
52
a signal from inside the cell that alteres gene expression is called
intracellular
53
a signal from outside the cell that alters gene expression is called
extracellular
54
name the 3 main forms of RNA used in gene expression
tRNA, mRNA, rRNA
55
where do you find rRNA
ribosome
56
which form of RNA is found in the nucleus and the cytoplasm
mRNA
57
what is the sugar found in RNA
ribose
58
What difference in bases is there between DNA and RNA
thymine is replaced with Uracil
59
how many strands do you find in DNA and RNA
2 in DNA, 1 in RNA
60
what enzyme creates the primary transcript in transcription
RNA polymerase
61
what functions (4) does RNA polymerase carry out
Untwists and Unzips gene, pairs up nucleotides and forms backbone
62
what is name for a triplet of bases on DNA/mRNA
codon
63
what is the name for the triplet of bases found on tRNA
anti-codon
64
what 2 main structural sites are needed on a tRNA molecule
anticodon and amino acid attachment site
65
what is the name of the sequence RNA polymerase binds to to start transcription
promotor
66
what process alters a primary transcript to a mature transcript
splicing
67
what process allows one gene to code for several proteins
alternative splicing
68
what sequences are removed during splicing
introns
69
what sequences are kept during splicing
exons
70
what is important about the sequence of exons during splicing
the sequence does not change
71
where does translation take place
ribosome
72
what codon types are required during translation (3)
start, coding, stop
73
what bond is formed between amino acids during translation
peptide
74
give an example of an interaction that helps form the 3D structure of a protein
hydrogen bonds, covalent bonds (link across chains), ionic bonds, hydrophobic interactions, Van der Waals (includes H Bonding)
75
give two properties of a stem cell
unspecialised, can self-renew
76
what is the term for a cell changing from unspecialised to specialised
differentiation
77
what is the name for unspecialised cells in plants
meristems
78
what term describes embryonic stem cells
pluripotent
79
what term describes cells which can form all cell types in the organism
pluripotent
80
what term describes cells which can form a subset of cell types
multipotent
81
what terms describes tissue stem cells
multipotent
82
what are tissue stem cells used for in the body (generally)
growth and repair
83
name a therapeutic use of stem cell
e.g. bone maroow transplants, corneal grafts, skin grafts….
84
name a research use of stem cells as model cells
e.g. new drug testing, cell growth, cell differentiation, gene expression…
85
stem cell research involves the destruction of early embryos. What term is used to describe the issues raised from this
ethical
86
what contains more sequence in the genome; coding or non-coding DNA
non-coding
87
all of the genetic material that can be passed on to offspring is called the…
genome
88
give examples of sequences which are transcribed but not translated
e.g. tRNA, rRNA, introns
89
give and example of why non-coding sequences needed on the genome
e.g. to regulate transcription, bind proteins, fold DNA….
90
a sequence of bases which codes for a protein is called a..
gene
91
A random change in DNA is called a..
mutation
92
name the 3 single gene mutations
substitution, insertion, deletion
93
what is meant by 'point mutation'
a single base change
94
what mutations cause a frame shift
insertion and deletion
95
a mutation that creates a stop codon is called a..
nonsense mutation
96
a mutation that changes the amino acid coded for is called a ..
missense mutation
97
a mutation that does not change the amino acid coded for is called a ..
silent mutation
98
a mutation that can result in introns remaining in coding is called a
splice-site mutation
99
a mutation that can result in exons being removed from code is a..
splice-site mutation
100
name the 4 chromosome mutations
deletion, inversion, translocation, duplication
101
A section of chromosome added from a homologous chromosomes whould cause which type of mutation
duplication
102
A section of chromosome removed would cause which type of mutation
deletion
103
A section of chromosome flipped over cause which type of mutation
inversion
104
a section of chromosome moved to a non-homologous chromosome is called
translocation
105
duplication allows change in a gene which still retaining original function, what process is this important for
evolution
106
the passing of genetic information from parent to offspring is called
vertical gene transfer
107
the passing of genetic information between individuals in the same generation is called
horizontal gene transfer
108
what type of organism regularly use horizontal gene transfer
prokaryotes
109
the non-random increase in the frequency of alleles that favour survival is called
natural selection
110
phenotypes which increase the likelyhood of survival are said to have a ..
selective advantage
111
give 3 examples of things which can apply a selction pressure
e.g. predators, grazers, disease, climate conditions…
112
what are the 3 forms of selection
stabilising selection, directional selection, disruptive selection
113
what will happen to the mean and range in stabilising selection
mean remains the same, range is decreased
114
what will happen to the mean and range in directional selection
the mean will shift and the range will remain the same around the mean (also shifted on axis)
115
what will happen to the mean and range in disruptive selection
the range will be split into 2 and 2 distinct means start to develop
116
give two reasons why evolution is faster in prokaryotes
horizontal gene transfer and short generation time
117
what is the sequence of events in speciation (4)
isolation of gene pools, mutation/variation, natural selection with different selective pressures, many generations
118
what is used as a test for stating speciation has occurred
when individuals from one population can no longer produce fertile offspring with the other
119
if an extreme phenotype is selected for, what form of selection occurs
directional
120
if the extremes of phenotype are selected against, what form of selection occurs
stabilising
121
if the two extremes of phenotype are selected for, what form of selection occurs
disruptive
122
what is the source of novel alleles in a population
mutation
123
what are the 3 forms of isolation barrier in speciation
geographical, behavioural, ecological
124
give an example of a geographical isolation barrier
e.g. sea, mountain, canyons….
125
give an example of an ecological isolation barrier
e.g. pH, temperature, habitat choice..
126
give an example of a behavioural isolation barrier
e.g. reproductive cycles out of sync, active times out of sync…
127
where subpopulations are isolated by geographical barrier the form of speciation is called..
allopatric
128
what form of isolation barrier causes allopatric speciation
geographical
129
where subpopulations are in the same geographical location what form of speciation can occur
sympatric
130
what form of isolation barrier causes sympatric speciation
ecological and behavioural
131
the use of comparisons of sequence data and statistical analysis is called..
bioinformatics
132
the branch point in a phylogentic tree shows a
common ancestor
133
phylogenetic trees normally have a scale in..
mya / millions of years ago
134
as well as sequence data, what other evidence is used to track evolution
fossil record
135
what can you conclude if there is a high level of conserved sequence between two species
that they are closely related
136
what are the three domains of life
eukaryotes, prokaryotes, archae
137
what is the universal common ancestor
the cell that all life on earth can be tracked back to
138
what is a molecular clock
a gene/protein sequence which has a known mutation rate, so divergence can be used to work out time
139
using genetic information to determine choice or dosage of drug is called
pharmacogenetics
140
give an ethical issue linked to personal genomics
e.g. genetic risk could be used by companies for job/access/insurance. Who 'owns' the sequence/information?
