Brainscape's Knowledge GenomeTM

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


See full index

Higher Biology 2021 > DNA & The Genome > Flashcards

DNA & The Genome Flashcards

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

What is the name for the basic units which make up strands of DNA?

A

Nucleotides.

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

What are the DNA base pairing rules?

A

Adenine to Thymine, Cytosine to Guanine are the DNA base pairing rules.

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

The two strands of DNA are held together by which kind of bonds?

A

Weak hydrogen bonds hold together two strands of DNA.

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

What are DNA nucleotides made up of?

A

DNA nucleotides are made up of: a deoxyribose sugar, phosphate and base.

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

DNA is found as linear chromosomes, tightly coiled and packaged with associated proteins, called histones, in which type of organism?

A

DNA is packaged like this in eukaryotes.

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

what are prokaryotes?

A

organisms that lack true membrane-bound nucleus.

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

where is the DNA found in prokaryotes?

A

Cytoplasm.

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

example of prokaryote

A

Bacteria is a type of prokaryote.

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

what are eukaryotes?

A

Organisms that have a membrane-bound nucleus that stores their genetic information.

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

example of eukaryotes

A

fungi, animals, and plants are examples of eukaryotes.

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

organisation of chromosomal DNA in prokaryotes?

A

Prokaryotes have circular DNA organisation.

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

plasmids are found in one type of eukaryote

A

Yeast cells are the only type of eukaryote that contains plasmids.

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

DNA is wrapped around _ _ _ _ _ _ _ _

A

DNA is wrapped around histones.

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

what does DNA polymerase need to be present before it can start replicating DNA?

A

primer.

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

True or False: The lagging strands are replicated continuously?

A

False- The lagging strands are replicated continously.

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

Fragments on lagging strands are joined then together using the enzyme DNA _ _ _ _ _ _ _

A

Fragments on lagging strands are joined then together using the enzyme DNA ligase.

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

DNA unwinding occurs at multiple locations along a DNA molecule at _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

A

DNA unwinding occurs at multiple locations along a DNA molecule at Replication Forks.

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

Which enzymes are required for DNA replication?

A

Ligase, DNA Polymerase

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

Why can both strands of DNA not be replicated continuously?

A

DNA nucleotides can only be added continuously in a 5’ to 3’ direction.

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

what is the name for the repeating units that make up a strand of DNA?

A

Nucleotides

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

What is a nucleotide made from?

A

Deoxyribose sugar, phosphate, base

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

Which end of the DNA strand is called the 3’ end?

A

End with the deoxyribose sugar

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

Which end of the DNA strand is called the 5’ end?

A

End with the phosphate

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

What shape is a DNA molecule?

A

Double helix

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

What is the complementary base pairing rule?

A

Adenine and Thymine always pair, Guanine and Cytosine always pair

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

What bonds hold the complementary base pairs together?

A

Weak hydrogen bonds

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

Which bonds hold the deoxyribose sugar of one nucleotide to the phosphate of another?

A

Strong chemical bonds

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

Why are DNA strands described as anti-parallel?

A

One strand runs from the 3’-5’ direction and the other runs in the 5’-3’ direction

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

Where do you find DNA in a eukaryote?

A

In the nucleus, in the mitochondria, in the chloroplast

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

How is DNA stored in prokaryotes?

A

As a large single, circular chromosome and in plasmids

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

what is a plasmid?

A

A small ring of DNA or small circular DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How is DNA stored in eukaryotes?

A

Linear chromosomes in the nucleus, small circular chromosomes in the mitochondria and chloroplast. Yeast has plasmids

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

How is DNA packaged within the nucleus of eukaryotes?

A

Tightly coiled and packaged with associated proteins called histones

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

What enzyme is responsible for DNA replication?

A

DNA polymerase

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

What is the function of a primer?

A

To provide a start point for DNA polymerase

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

Why is DNA replication required?

A

Before mitosis to ensure that both daughter cells get an identical copy of the genetic info from the parent cell

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

What is required in order for DNA replication to take place?

A 
DNA polymerase 
Ligase enzymes 
DNA nucleotides 
Primers 
Template DNA
ATP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Which enzyme joins the fragments of DNA on the lagging strand?

A

Ligase

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

Which bonds are broken to separate the two strands of DNA?

A

Hydrogen bonds

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

What is mean by discontinuous synthesis of the lagging strand?

A

Strand is replicated in fragments

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

What is a primer?

A

A short strand of nucleotides which binds to the 3’ end of the template strand allowing DNA polymerase to add nucleotides.

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

What is the function of PCR?

A

To amplify a sequence of DNA

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

What are the requirements for PCR?

A 
Template DNA
heat tolerant
DNA polymerase 
Primers 
Free DNA nucleotides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

When is PCR used?

A

Crime scene analysis
Paternity tests
Diagnosing genetic disorders

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

Why are there multiple replication forks on one strand of DNA?

A

To allow speedy replication

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

Why is DNA heated in the first stage of PCR?

A

To break hydrogen bonds between bases and separate the two strands

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

Why is DNA cooled during the second stage of PCR?

A

To allow primers to bind to target sequences

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

Why is heat-tolerant DNA polymerase used in PCR?

A

It doesn’t denature during the hearing cycles.

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

Why is DNA heated back up for the third stage of PCR?

A

To allow heat tolerant DNA polymerase to replicate the region of DNA

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

What are the primers used in PCR?

A

Short strands of nucleotides which are complementary to specific target sequences at the two ends of the region of the DNA to be amplified

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What temperature does the first stage of PCR occur at?

A

95^C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What temperature does the second stage of PCR occur at?

A

58^C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What temperature does the third stage of PCR occur at?

A

75^C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Why is there a leading and lagging strand in DNA replication?

A

Parent strands are anti-parallel but DNA polymerase can only add DNA nucleotides to the 3’ end of the new DNA strand which is forming

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is the difference between DNA polymerase and heat-tolerant polymerase?

A

DNA polymerase denatures at lower temperatures than heat-tolerant polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Which bonds are synthesised by DNA / heat-tolerant DNA polymerase?

A

Strong chemical bonds / covalent bonds between sugar and phosphates of adjacent nucleotides.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Which rule allows the molecules of DNA to be copied?

A

Complementary base pairing rule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Which strand in DNA replication requires the use of many primers?

A

Lagging strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Which enzyme is responsible for transcription?

A

RNA polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Which process produces a primary mRNA transcript?

A

Transcription

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Which process takes place to turn a primary mRNA transcript into a mature mRNA molecule?

A

RNA splicing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Which process is when the mature mRNA is used to direct the synthesis of a protein?

A

Translation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Gene expression involves which two processes?

A

transcription and translation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Where does transcription take place?

A

In the nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Where does translation take place?

A

At the ribosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Which molecule carries specific amino acids to the ribosome?

A

tRNA

67
Q

What is the ribosome composed of?

A

rRNA and protein

68
Q

What is the function of RNA polymerase?

A

Unwinds the double helix and breaks the hydrogen bonds between the bases. It synthesises a primary transcript of mRNA from RNA nucleotides by complementary base pairing.

69
Q

Describe the complementary base pairing used to build a molecule of RNA.

A

Adenine—Uracil, Cytosine—Guanine

70
Q

Which bonds hold amino acids together to form a polypeptide?

A

Peptide bond

71
Q

What happens during RNA splicing?

A

Introns are removed and exons are joined together to form the mature transcript.

72
Q

Which codons begin and end translation?

A

START and STOP codons.

73
Q

What is the function of tRNA?

A

Carries a specific amino acid to the ribosome and has an anticodon which is complementary to a codon.

74
Q

What is the function of mRNA?

A

It carries a complimentary copy of the DNA code from the nucleus to a ribosome in the cytoplasm.

75
Q

What is determined by the proteins produced during gene expression?

A

the phenotype of the organism

76
Q

What is alternative RNA splicing?

A

When introns are treated as exons or exons are treated as introns leading to different exons retained in the mature mRNA.

77
Q

How can one gene lead to the production of many proteins?

A

RNA alternative splicing

78
Q

Proteins have a 3D what interactions are involved in this?

A

Hydrogen bonds between amino acids and other interactions between individual amino acids.

79
Q

What is an intron?

A

A non-coding region of mRNA.

80
Q

What is an exon?

A

Coding region of mRNA.

81
Q

Describe the structure of a tRNA?

A

It folds due to complementary base pairing and has an amino acid attachment site at one end and an anti-codon at the other end.

82
Q

What is the three types of RNA involved in gene expression?

A

mRNA, tRNA and rRNA.

83
Q

What is an anti-codon?

A

an exposed triplet of bases on the tRNA.

84
Q

What happens during translation at the ribosome?

A

tRNA with complementary anticodons bond with codons on the mRNA by complimentary base pairing, translating the code into a sequence of amino acids. Peptide bonds form between amino acids.

85
Q

What are the differences between RNA and DNA nucleotides?

A

RNA contains RIBOSE SUGAR and URACIL and is SINGLE stranded, DNA contains DEOXYRIBOSE SUGAR and THYMINE and is DOUBLE stranded.

86
Q

What is a codon?

A

A sequence of three bases on mRNA which codes for one specific amino acid.

87
Q

What is meant by cellular differentiation?

A

Process by which a cell expresses certain genes to produce proteins characteristic for that type of cell.

88
Q

What is a meristem?

A

Region of unspecialised cells in plants capable of cell division and/or differentiation.

89
Q

What is a stem cell?

A

Unspecialised cells in animals which can divide (self-renew) and/or differentiate to form specialised cells.

90
Q

What is the difference between tissue (adult) stem cells and embryonic stem cells?

A

Tissue (adult) stem cells can only differentiate into all types of cell found in a particular tissue (multipotent) but embryonic stem cells can become all the cell types needed by the organism (pluripotent)

91
Q

What does pluripotent mean?

A

Can differentiate into all the cell types that make up the organism.

92
Q

What does multipotent mean?

A

Can differentiate into a limited range of cells/ all types of cell found in a particular tissue.

93
Q

Why do organisms have tissue (adult) stem cells?

A

To grow, repair and replenish/renew differentiated cells that are found in tissues.

94
Q

Why do people have ethical concerns with the use of embryonic stem cells?

A

Embryos get destroyed which some people think is the same as murder/ killing a potential life.

95
Q

What are the two therapeutic uses of stem cells?

A

Corneal repair and growing skin grafts for regeneration of damaged skin.

96
Q

What are some of the ways that stem cells can be used in research?

A

Used as model cells to test drugs, used to study cell processes like cell growth, differentiation and gene regulation and to study how diseases develop.

97
Q

Give an example of a tissue adult stem cell?

A

Blood stem cells in bone marrow which go on to differentiate into all the cells of the blood.

98
Q

How can stem cells found in the embryo differentiate into all cell types?

A

All the genes in embryonic stem cells can be switched on.

99
Q

What type of stem cells are pluripotent?

A

Embryonic stem cells.

100
Q

What type of stem cells are multipotent?

A

Tissue stem cells.

101
Q

What is meant by the genome?

A

An organisms entire hereditary information encoded within its DNA.

102
Q

What is meant by a coding region of the genome?

A

A region of DNA that is translated.

103
Q

What is meant by a non-coding region of the genome?

A

It does not code for protein.

104
Q

What are the known functions of the non-coding regions?

A

Regulate transcription or are transcribed but not translated.

105
Q

What are most of eukaryotes genomes consisted of?

A

Non-coding sequences.

106
Q

What is an example of non-translated forms of RNA?

A

tRNA and rRNA.

107
Q

What is meant by transcription?

A

Sequence of DNA is copied to make RNA molecule.

108
Q

What is meant by translation?

A

Sequence of mRNA used to create protein.

109
Q

What is the function of rRNA?

A

Combines with protein to form the ribosome.

110
Q

What is the function of tRNA?

A

Carries a specific amino acid and has an anticodon which is complementary to a codon on mRNA.

111
Q

Is all of the genome found in the nucleus of eukaryotes?

A

No, also in mitochondria or chloroplasts

112
Q

What is a mutation?

A

A random change in the DNA that can result in no protein or an altered protein being synthesised.

113
Q

Name the three types of single-gene mutations?

A

Substitution, Insertion, Deletion

114
Q

Name the four types of chromosomes mutations?

A

Translocation, Inversion, Deletion, Duplication

115
Q

What happens in a substitution mutation?

A

One base is replaced by another

116
Q

What happens during deletion point mutations?

A

One base is removed

117
Q

What happens during insertion point mutations?

A

One base is added

118
Q

What is meant by a missense mutation?

A

When one amino acid has been substituted and this results in a non-functional protein or may have little effect on the protein.

119
Q

What is meant by a nonsense mutation?

A

When a premature stop codon has been inserted and results in a shorter protein.

120
Q

What is the result of a splice-site mutation?

A

In some introns being retained in the mature mRNA and/or some exons not being included in the mature transcript.

121
Q

Which mutations are frameshift mutations?

A

Insertion and deletion

122
Q

What is meant by a frameshift mutation?

A

Causes all of the codons and all of the amino acids after the mutation to be changed. This has a major effect on the protein produced.

123
Q

What is meant by a chromosome mutation?

A

A change to the sequence of genes on a chromosome.

124
Q

What happens in a translocation mutation?

A

A section of a chromosome is added to another chromosome, not a homologous partner.

125
Q

What happens in an inversion mutation?

A

Where a section of a chromosome is reversed.

126
Q

What happens in a deletion chromosome mutation?

A

A section of a chromosome is removed.

127
Q

What happens in a duplication mutation?

A

A section of a chromosome is added from its homologous partner.

128
Q

What is a mutagenic agent?

A

Something which increases the frequency of mutations.

129
Q

Give an example of a mutagenic agent?

A

Mustard gas, U.V. Radiation, X-Rays

130
Q

Why is duplication important in evolution?

A

duplication allows potential beneficial mutations to occur in a duplicated gene whilst the original gene can still be expressed to produce its protein.

131
Q

Which type of point mutation can lead to an expansion of a nucleotide sequence?

A

Insertion

132
Q

Explain how a mutation can lead to the same amino acid being produced?

A

Many amino acids have more than one codon.

133
Q

What is evolution?

A

The changes in organisms over generations as a result of genomic variation.

134
Q

What is meant by vertical gene transfer?

A

where genes are transferred from parents to offspring by sexual or asexual reproduction.

135
Q

What is meant by horizontal gene transfer?

A

Where genes are transferred between individuals in the same generation.

136
Q

Which type of gene transfer leads to rapid evolutionary change?

A

Horizontal Gene Transfer

137
Q

Which organisms only transfer genetic material by vertical gene transfer?

A

Eukaryotes

138
Q

Which organisms can transfer genetic information by both vertical and horizontal gene transfer?

A

Prokaryotes

139
Q

What is speciation?

A

The generation of new species by evolution as a result of isolation, mutation, and selection.

140
Q

What is Natural Selection?

A

The non-random increase in the frequency of DNA sequences increases survival and non-random reduction in the frequency of deleterious sequences.

141
Q

What is the definition of a species?

A

A group of organisms that can interbreed to produce fertile offspring.

142
Q

What is meant by ‘stabilising selection’?

A

An average phenotype is selected for and extremes of the phenotype range are selected against.

143
Q

What is meant by ‘disruptive selection’?

A

Two or more phenotypes are slected for.

144
Q

What is meant by ‘directional selection’?

A

One extreme of the phenotype range is selected for.

145
Q

Summarise natural selection.

A

Organisms who are better adapted to their environment are more likely to survive to pass on their genes.

146
Q

What is the importance of isolation barriers?

A

They prevent gene flow between sub-populations during speciation.

147
Q

What is meant by sympatric speciation?

A

Speciation brought about by a behavioural or ecological barrier e.g. different breeding seasons, different mating rituals

148
Q

How do you know if organisms have undergone speciation?

A

They can no longer interbreed to produce fertile offspring.

149
Q

What is meant by allopatric speciation?

A

Speciation brought about by geographical barriers e.g. river, sea, mountain range.

150
Q

What is genomics?

A

The study of genomes

151
Q

What is genomic sequencing?

A

Determines the sequence of nucleotide bases for individual genes or entire genomes.

152
Q

What is bioinformatics?

A

The use of computers and statistical analysis to compare sequence data.

153
Q

What are three types of organisms which have had their genome sequences?

A

Pest species, disease-causing organisms and model organisms.

154
Q

What is phylogenetics?

A

The study of evolutionary history and relationships.

155
Q

What was the order of evolution of life on earth?

A

Last universal ancestor, prokaryotes, photosynthesis, eukaryotes, multicellular organisms, animals, vertebrates, land plants

156
Q

How can we work out the sequence of evolution of life on Earth?

A

Using sequence data and fossil evidence.

157
Q

How is a molecular clock constructed?

A

They assume a constant mutation rate and show differences in DNA sequences or amino acid sequences. The difference in sequences indicates the time of divergence from a common ancestor.

158
Q

How could differences in DNA sequences tell you how distantly related two organisms are?

A

The more differences in the DNA sequences the more distantly related.

159
Q

What is pharmacogenetics?

A

The use of genome information in the choice of drugs.

160
Q

What are the three domains of life?

A

Archaea, bacteria, eukaryotes

161
Q

What is personalised medicine?

A

An individual’s genome sequence can be used to select the most effective drugs and dosage to treat their disease.

162
Q

Comparison of genomes has revealed?

A

That many genes are highly conserved across different organisms.

163
Q

What is used to identify base sequences?

A

Computer programs, by looking for sequences similar to known genes.

Higher Biology 2021 (1 decks)

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