34 Questions
Which type of point mutation results in a premature stop codon?
Nonsense
What is the main consequence of a frameshift mutation caused by an insertion?
Shift in the reading frame of the genetic message
What can result if a point mutation occurs at a position where the stop codon is displaced?
The protein may be elongated
What does an insertion mutation influence the most directly?
The entire reading frame of the gene sequence
Which of the following types of mutations can render a protein incapable of performing its normal functions due to a frameshift?
Insertion and deletion mutations
Which type of chromosomal mutation involves part of one chromosome breaking off and attaching to another non-homologous chromosome?
Translocation
Which chromosomal mutation results in a chromosome segment being reversed end to end?
Inversion
Which chromosomal mutation decreases the overall genetic material in a chromosome?
Deletion
In which type of chromosomal mutation does an extra copy of a part of a chromosome get produced?
Duplication
Which statement about the effects of mutations is accurate?
Mutations can sometimes have no noticeable effect.
What term is used to describe heritable changes in genetic information?
Mutations
Which Latin word is 'mutation' derived from?
Mutare
Which type of mutation involves the change of a single base pair?
Point mutation
What are mutations that do not affect the amino acid sequence called?
Silent mutations
How would changing the mRNA codon from CCC to ACC affect the protein?
It changes proline to threonine
What is the result of a substitution mutation in point mutations?
One base is changed to a different base
Which of the following best describes a missense mutation?
A mutation that changes the amino acid specified by a codon
If a codon changes from CCC to CCA, what amino acid is specified?
Proline
What can increase the error rate of DNA replication?
Compounds that interfere with base-pairing
Which of the following can result in chromosomal mutations?
UV radiation causing breaks and inversions
What is one potential benefit of mutations?
They are the source of genetic variability.
What is a characteristic effect of some of the most harmful mutations?
They change protein structure or gene activity adversely.
Which type of mutation may not change the amino acid specified by a codon?
Silent mutation
What condition must individuals with xeroderma pigmentosum avoid due to their increased risk of skin cancer?
Sunlight
Which root word means 'producing'?
gen
What is an example of a chemical mutagen?
Tobacco smoke
What is one benefit of mutations in the mosquito genome for mosquitoes?
Making them resistant to chemical pesticides
What is polyploidy?
The condition where an organism has extra sets of chromosomes
Which of the following is a polyploid crop plant?
Banana
Which of the following best describes how some polyploidy in plants is achieved?
By a complete set of chromosomes failing to separate during meiosis
Why is polyploidy generally lethal in animals but beneficial in plants?
Plants can better adapt to chromosome number changes
Which of the following describes a possible human benefit of mutations?
Increased resistance to HIV
What is NOT a possible way a mutation may affect an organism?
Guaranteeing a better survival rate
Which of the following is the best possible explanation for a cell suddenly producing different proteins after many years?
The cell has been infected by a virus altering its genetic material
Study Notes
Mutations
- A mutation is a heritable change in genetic information, involving a change in the sequence of nucleotides in DNA or a change in the number or structure of chromosomes.
Point Mutations
- A point mutation changes a single base pair in the DNA sequence.
- Point mutations usually involve a substitution, where one base is changed to a different base.
- Substitutions can be silent, affecting no amino acid, or missense, changing the amino acid specified by a codon.
Types of Mutations
- Frameshift mutations: not expounded upon in the text.
- Polyploidy: a condition where an organism has extra sets of chromosomes, often larger and stronger than diploid organisms.
Causes of Mutations
- Mutagens: chemical or physical agents in the environment, such as UV radiation, pesticides, tobacco smoke, and environmental pollutants.
- Errors during DNA replication can also cause mutations.
Effects of Mutations
- Harmful effects: disrupt normal gene function, leading to genetic disorders, cancers, and other negative outcomes.
- Helpful effects: produce new or altered protein functions, beneficial to the organism or species, such as increased resistance to disease or environmental stressors.
Applications of Mutations
- Plant and animal breeders utilize "good" mutations to produce desirable traits, such as stronger and larger plants.
- Mutations can lead to the development of new crop species, such as bananas and strawberries.
Mutagens and Repair
- Cells can repair some DNA damage, but permanent changes can occur if they cannot.
- Mutagens can increase the error rate of DNA replication, leading to mutations.
Learn about mutations, how they change genetic information, and their effects on genes. Discover the different types of mutations and their impact on genetic code.
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