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Biology HL - IB > Mutation and gene editing > Flashcards

Mutation and gene editing Flashcards

1
Q

What is a gene mutation?

A

A gene mutation is a structural change in the DNA sequence of a gene that can affect the function of the resulting protein.

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2
Q

What are the three main types of gene mutations?

A

The three main types of gene mutations are substitutions, insertions, and deletions.

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3
Q

What is a substitution mutation?

A

A substitution mutation occurs when one nucleotide in the DNA sequence is replaced by another nucleotide, potentially altering the corresponding amino acid.

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4
Q

How can a substitution mutation affect protein function?

A

A substitution can lead to a silent mutation (no change), a missense mutation (different amino acid), or a nonsense mutation (premature stop codon), impacting protein function.

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5
Q

What is an insertion mutation?

A

An insertion mutation involves adding one or more nucleotides into the DNA sequence, which can shift the reading frame and alter the entire downstream amino acid sequence.

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6
Q

What are the potential effects of an insertion mutation on protein synthesis?

A

An insertion can cause frameshift mutations, leading to significant changes in protein structure and function, or it may introduce new amino acids if it occurs in multiples of three.

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7
Q

What is a deletion mutation?

A

A deletion mutation occurs when one or more nucleotides are removed from the DNA sequence, which can also result in a frameshift and alter protein synthesis.

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8
Q

How do deletions impact gene expression?

A

Deletions can disrupt the reading frame, leading to altered amino acid sequences and potentially nonfunctional proteins.

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9
Q

Why is it important to understand gene mutations?

A

Understanding gene mutations is crucial for studying genetic diseases, evolution, and mechanisms of genetic variation within populations.

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10
Q

How do different types of mutations contribute to genetic diversity?

A

Mutations introduce new alleles into a population, contributing to genetic diversity and providing raw material for natural selection and evolution.

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11
Q

What is a base substitution mutation?

A

A base substitution mutation occurs when one nucleotide in the DNA sequence is replaced by another nucleotide.

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12
Q

What are single-nucleotide polymorphisms (SNPs)?

A

SNPs are variations in a single nucleotide that occur at specific positions in the genome and are often the result of base substitution mutations.

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13
Q

How can base substitutions affect protein synthesis?

A

Base substitutions can change the amino acid sequence of a protein, potentially altering its structure and function.

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14
Q

What is a silent mutation?

A

A silent mutation is a type of base substitution that does not change the amino acid sequence due to the redundancy of the genetic code.

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15
Q

What is a missense mutation?

A

A missense mutation is a base substitution that results in the incorporation of a different amino acid into the polypeptide chain, which may affect protein function.

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16
Q

What is a nonsense mutation?

A

A nonsense mutation is a base substitution that creates a premature stop codon, leading to truncated proteins that are usually nonfunctional.

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17
Q

Why does degeneracy in the genetic code matter for base substitutions?

A

The degeneracy of the genetic code means that multiple codons can code for the same amino acid, so some base substitutions may not affect protein function.

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18
Q

How do SNPs contribute to genetic diversity?

A

SNPs introduce variations in the DNA sequence, contributing to genetic diversity within populations and influencing traits and susceptibility to diseases.

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19
Q

What role do SNPs play in personalized medicine?

A

SNPs can influence individual responses to drugs and susceptibility to diseases, allowing for tailored medical treatments based on genetic profiles.

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19
Q

What are insertions and deletions in the context of gene mutations?

A

Insertions and deletions are types of mutations where one or more nucleotides are added (insertion) or removed (deletion) from the DNA sequence.

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19
Q

Why is understanding base substitutions important in molecular biology?

A

Understanding base substitutions helps elucidate mechanisms of genetic variation, evolution, and the basis of many genetic disorders.

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20
Q

How can insertions affect protein synthesis?

A

Insertions can lead to frameshift mutations, altering the reading frame of the genetic code and potentially changing the entire amino acid sequence downstream.

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21
Q

How do deletions impact gene expression?

A

Deletions can also cause frameshift mutations, which may result in altered amino acid sequences and nonfunctional proteins.

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22
Q

What is the likelihood that insertions or deletions will cause polypeptides to cease functioning?

A

The likelihood is high, as frameshift mutations often produce proteins that are truncated or have incorrect amino acid sequences, rendering them nonfunctional.

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23
Can insertions and deletions affect multiple genes?
Yes, large insertions or deletions can disrupt multiple genes or regulatory elements, leading to broader effects on gene expression and function.
24
Why is it important to understand the consequences of insertions and deletions?
Understanding these mutations helps elucidate mechanisms of genetic disorders, evolution, and the functional impact of genetic variation.
25
What role do insertion and deletion mutations play in evolution?
Insertions and deletions can introduce new genetic variations that may confer advantages or disadvantages, influencing evolutionary processes.
26
How can cells repair insertion and deletion mutations?
Cells have DNA repair mechanisms that can correct these mutations; however, if unrepaired, they may lead to permanent changes in the genome.
27
What is an example of a disease caused by insertion or deletion mutations?
Cystic fibrosis can result from a deletion mutation in the CFTR gene, leading to dysfunctional protein production and associated symptoms.
28
What are the primary causes of gene mutations?
Gene mutations can be caused by mutagens and errors in DNA replication or repair.
29
What are mutagens?
Mutagens are agents that increase the frequency of mutations in DNA, leading to changes in the genetic sequence.
30
Can you provide examples of chemical mutagens?
Examples of chemical mutagens include alkylating agents (like mustard gas), base analogs (like 5-bromouracil), and intercalating agents (like ethidium bromide).
31
How do chemical mutagens induce mutations?
Chemical mutagens can alter DNA bases, disrupt base pairing, or cause misincorporation of nucleotides during DNA replication.
32
What are mutagenic forms of radiation?
Mutagenic forms of radiation include ultraviolet (UV) light, X-rays, and gamma rays, which can cause DNA damage.
33
How does ultraviolet (UV) radiation lead to mutations?
UV radiation can cause the formation of pyrimidine dimers, which distort the DNA structure and interfere with normal base pairing during replication.
34
What role do errors in DNA replication play in mutations?
Errors during DNA replication can result in incorrect base pairing, leading to substitutions, insertions, or deletions in the DNA sequence.
35
How does DNA repair contribute to mutation prevention?
DNA repair mechanisms correct errors that occur during replication or damage caused by mutagens, reducing the likelihood of permanent mutations.
36
Why is it important to understand the causes of gene mutations?
Understanding the causes of gene mutations is essential for studying genetic diseases, cancer development, and mechanisms of evolution.
37
How can exposure to mutagens impact human health?
Exposure to mutagens can increase the risk of developing genetic disorders and cancers due to the accumulation of harmful mutations in critical genes.
38
What is the nature of mutations in a genome?
Mutations can occur randomly anywhere in the base sequences of a genome, affecting various genes and regulatory regions.
39
Are some bases more likely to mutate than others?
Yes, certain bases have a higher probability of mutating due to their chemical structure or position within the genome.
40
What is meant by "randomness" in the context of mutations?
Randomness refers to the unpredictable nature of where mutations may occur, without any directed mechanism to target specific bases.
41
Can mutations be deliberately induced to change a trait?
No natural mechanism is known for making deliberate changes to a particular base with the purpose of altering a specific trait.
42
How does the randomness of mutations contribute to genetic diversity?
Random mutations introduce variations in the genetic material, which can lead to new traits and contribute to the evolutionary process.
43
What role do mutagens play in mutation randomness?
Mutagens can increase the frequency of random mutations by causing changes in DNA, but they do not target specific genes or bases.
44
How can the randomness of mutations affect evolutionary adaptation?
Random mutations provide raw material for natural selection, allowing advantageous traits to be preserved and passed on through generations.
45
Why is it important to understand the randomness of mutations in molecular biology?
Understanding mutation randomness helps researchers study genetic variation, evolution, and mechanisms underlying genetic diseases.
46
What impact does mutation randomness have on populations over time?
Over time, random mutations can lead to significant genetic variation within populations, influencing adaptability and survival.
47
How do errors in DNA replication contribute to mutation randomness?
Errors during DNA replication can introduce random mutations into the genome, further increasing genetic diversity and potential evolutionary changes.
48
What are germ cells?
Germ cells are reproductive cells (sperm and eggs) that give rise to gametes and can pass genetic information to the next generation.
49
What is the consequence of mutations in germ cells?
Mutations in germ cells can be inherited by offspring, potentially leading to genetic disorders or variations in traits.
50
What are somatic cells?
Somatic cells are all body cells except for germ cells; they make up tissues and organs and do not contribute to the next generation.
51
How do mutations in somatic cells affect an organism?
Mutations in somatic cells can lead to cellular dysfunction, contributing to diseases such as cancer, but they are not passed on to offspring.
52
What is the significance of inherited mutations from germ cells?
Inherited mutations can affect the phenotype of the offspring, potentially leading to hereditary diseases or advantageous traits.
53
How can mutations in somatic cells lead to cancer?
Mutations in somatic cells can disrupt normal cell cycle regulation, leading to uncontrolled cell division and tumor formation.
54
What is a key difference between germline mutations and somatic mutations?
Germline mutations are heritable and affect future generations, while somatic mutations are not inherited and affect only the individual organism.
55
Why is it important to study both germ cell and somatic cell mutations?
Understanding both types of mutations helps researchers investigate genetic diseases, cancer mechanisms, and evolutionary processes.
56
Can somatic mutations have effects on health?
Yes, somatic mutations can lead to various health issues, including cancer, autoimmune diseases, and other conditions related to cellular malfunction.
57
How does the environment influence mutation rates in germ and somatic cells?
Environmental factors such as radiation, chemicals, and lifestyle choices can increase mutation rates in both germ and somatic cells, impacting health and heredity.
58
What is the primary source of genetic variation?
Gene mutations are the original source of all genetic variation within a population.
59
How do mutations contribute to evolution?
While most mutations are harmful or neutral, they provide the raw material for natural selection, enabling species to adapt and evolve over time.
60
What types of mutations can introduce genetic variation?
Mutations can include substitutions, insertions, deletions, and larger chromosomal changes, all of which can create new alleles.
61
Why are most mutations considered harmful or neutral?
Many mutations disrupt normal gene function or protein structure, leading to negative effects; others may have no impact on the organism's fitness.
62
What is the role of beneficial mutations in evolution?
Beneficial mutations can confer advantages that improve survival or reproductive success, allowing those traits to be passed on to future generations.
63
How do SNPs (single-nucleotide polymorphisms) contribute to genetic variation?
SNPs are common types of mutations that can lead to differences in traits among individuals and are a significant source of genetic diversity.
64
What is the significance of understanding mutation in relation to human health?
Understanding mutations helps in identifying genetic predispositions to diseases and informs approaches in personalized medicine and genetic counseling.
65
How can commercial genetic tests provide insights into health risks?
Genetic tests can reveal SNPs and other mutations associated with increased risks for certain diseases, aiding in preventive healthcare strategies.
66
What is a potential downside of genetic testing without expert interpretation?
Without expert interpretation, individuals may misinterpret their genetic risk information, leading to unnecessary anxiety or inappropriate health decisions.
67
Why is it important to appreciate the role of mutation in biodiversity?
Appreciating mutation as a source of genetic variation highlights its essential role in maintaining biodiversity and enabling species to adapt to changing environments.
68
What is a gene knockout?
A gene knockout is a genetic technique used to make a specific gene inoperative, allowing researchers to study its function by observing the effects of its absence.
69
How does gene knockout help in understanding gene function?
By disabling a gene, scientists can observe phenotypic changes and infer the role of that gene in biological processes.
70
What types of organisms are commonly used for gene knockout studies?
Model organisms such as mice, zebrafish, and yeast are frequently used for gene knockout research due to their well-characterized genomes and biological relevance.
71
Why is it important to have a library of knockout organisms?
A library of knockout organisms provides researchers with a valuable resource to study various genes and their functions across different biological contexts.
72
What are some potential applications of gene knockout techniques?
Applications include studying genetic diseases, understanding developmental processes, and identifying targets for drug development.
73
How does creating a knockout organism typically work at the molecular level?
Techniques such as CRISPR-Cas9 or homologous recombination are used to introduce mutations that disrupt the target gene's function.
74
What is one limitation of using gene knockout techniques?
Gene knockouts can sometimes lead to compensatory mechanisms in the organism, making it difficult to attribute observed effects solely to the knocked-out gene.
75
How can gene knockouts contribute to our understanding of complex traits?
By analyzing multiple knockouts, researchers can investigate interactions between genes and their contributions to complex traits or diseases.
76
Why is expert interpretation important when analyzing results from knockout studies?
Expert interpretation is crucial to accurately assess the implications of observed phenotypes and understand the broader biological context.
77
What is an ethical consideration related to gene knockout research?
Ethical considerations include ensuring humane treatment of model organisms and addressing potential implications of genetic modifications in other species or humans.
78
What is CRISPR?
CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is a revolutionary gene-editing technology that allows for precise modifications to DNA sequences.
79
What role does the enzyme Cas9 play in CRISPR technology?
Cas9 is a nuclease that cuts DNA at specific locations, guided by RNA sequences, enabling targeted gene editing.
80
How does the CRISPR-Cas9 system work?
The system uses a guide RNA to direct Cas9 to a specific DNA sequence, where it makes a double-strand break, allowing for gene modification.
81
What is one successful application of CRISPR technology?
One successful application includes the development of genetically modified crops with enhanced traits, such as increased resistance to pests or improved nutritional content.
82
Why is CRISPR considered a powerful tool for gene editing?
CRISPR is considered powerful due to its precision, efficiency, and versatility, allowing researchers to edit genes in various organisms quickly.
83
What are some potential uses of CRISPR technology in medicine?
Potential uses in medicine include correcting genetic defects, developing gene therapies for diseases, and creating animal models for research.
84
What ethical issues are associated with the use of CRISPR technology?
Ethical issues include concerns about unintended consequences, such as off-target effects that may cause unintentional mutations. Germline editing raises implications for future generations, as changes would be inherited. The potential for "designer babies" refers to the possibility of selecting traits like intelligence or physical appearance, leading to social inequality and ethical dilemmas regarding human enhancement.
85
How do regulatory systems vary regarding CRISPR applications?
Regulatory systems differ across countries, affecting how CRISPR technology can be applied in research and clinical settings.
86
Why is there an international effort to harmonize regulations on genome editing technologies?
Harmonizing regulations aims to ensure safety, ethical standards, and responsible use of genome editing technologies like CRISPR globally.
87
What is the significance of expert interpretation in the context of CRISPR research?
Expert interpretation is crucial for understanding the implications of CRISPR findings and ensuring ethical considerations are addressed in applications and research outcomes.
88
What are conserved sequences in genes?
Conserved sequences are identical or similar DNA sequences found across different species, indicating evolutionary significance.
89
What are highly conserved sequences?
Highly conserved sequences are identical or similar across long evolutionary periods, suggesting critical functional roles in biological processes.
90
What is one hypothesis for the conservation of gene sequences?
One hypothesis is that conserved sequences are essential for the functional requirements of the gene products, meaning they play vital roles in organismal survival.
91
How do functional requirements contribute to sequence conservation?
If a gene product is crucial for a specific biological function, any mutations may be detrimental, leading to the preservation of the original sequence through natural selection.
92
What is another hypothesis regarding conserved sequences?
Another hypothesis is that conserved sequences experience slower rates of mutation due to their critical roles, making them less susceptible to changes over time.
93
How does slower mutation rates affect sequence conservation?
Slower mutation rates in essential genes reduce the likelihood of alterations that could disrupt function, thus maintaining sequence integrity across generations.
94
Why is understanding conserved sequences important in evolutionary biology?
Understanding conserved sequences helps identify genes that are critical for life and provides insights into evolutionary relationships among species.
95
How can researchers study conserved sequences?
Researchers can compare genomic sequences across different species to identify conserved regions and infer their functional significance.
96
What role do bioinformatics tools play in analyzing conserved sequences?
Bioinformatics tools allow scientists to analyze large genomic datasets, facilitating the identification and comparison of conserved sequences across species.
97
Why might some mutations in non-conserved regions be tolerated?
Mutations in non-conserved regions may not significantly impact protein function or organismal fitness, allowing for greater variability without detrimental effects.

Biology HL - IB (35 decks)

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