Mutations And Molecular Evolution
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Of the following terms, which one is likely to be the MOST common?
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Point mutation
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Missense mutation
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Base-pair substitution
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Nonsense mutation
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Frameshift mutation
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In the normal being of a person, we have genetics, which dictates among other things, how our bodies develop. At times, the normal never happens. Mutations and molecular evolution quiz below has more on the subject.
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- 2.
Sickle-cell disease is probably the result of which kind of mutation?
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Point only
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Frameshift only
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Nonsense only
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Nondisjunction only
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Both B and D
Correct Answer
A. Point onlyExplanation
Sickle-cell disease is caused by a specific point mutation in the gene that codes for hemoglobin, the protein responsible for carrying oxygen in red blood cells. This mutation results in a single nucleotide change in the DNA sequence, leading to the production of abnormal hemoglobin molecules. Therefore, the correct answer is "Point only" as the disease is not caused by frameshift mutations, nonsense mutations, or nondisjunction.Rate this question:
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- 3.
Which of the following would be responsible for an increased rate of mutation?
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Ultrasound
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Ultraviolet light
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Infra-red light
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Ultraviolent light
Correct Answer
A. Ultraviolet lightExplanation
Ultraviolet (UV) light would be responsible for an increased rate of mutation. UV light is a form of electromagnetic radiation that can cause damage to the DNA molecule. When UV light interacts with DNA, it can lead to the formation of covalent bonds between adjacent pyrimidine bases, particularly thymine. This can result in the formation of thymine dimers, which disrupt the normal structure of DNA and can lead to errors during DNA replication. These errors can manifest as mutations, altering the genetic code and potentially leading to genetic disorders or diseases.Rate this question:
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- 4.
If a frameshift mutation causes a stop codon to be inserted into the DNA sequence...
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The resulting protein will not be affected
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The phenotype will change but not the genotype
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The resulting protein will be too short and non-functional
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The resulting protein will be too long and non-functional
Correct Answer
A. The resulting protein will be too short and non-functionalExplanation
A frameshift mutation causes a shift in the reading frame of the DNA sequence, altering the way the sequence is translated into a protein. If a stop codon is inserted into the DNA sequence as a result of the frameshift mutation, it will prematurely terminate the translation process. This means that the resulting protein will be truncated and shorter than normal. Additionally, the premature stop codon may disrupt the normal folding and function of the protein, rendering it non-functional. Therefore, the correct answer is that the resulting protein will be too short and non-functional.Rate this question:
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- 5.
A nucleotide deletion in DNA replication...
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Causes one amino acid of the protein to be incorrect
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Causes all of the amino acids of the protein to be incorrect
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Causes the amino acids inserted after the deletion to be incorrect
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Causes the amino acids inserted before the deletion to be incorrect
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Has no effect on the resulting protein
Correct Answer
A. Causes the amino acids inserted after the deletion to be incorrectExplanation
A nucleotide deletion in DNA replication causes the amino acids inserted after the deletion to be incorrect. This is because a nucleotide deletion shifts the reading frame of the DNA sequence, leading to a change in the codons that specify the amino acids. As a result, the subsequent codons and amino acids will be altered, leading to incorrect protein synthesis.Rate this question:
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- 6.
The addition of a single nucleotide to the DNA sequence causes a frameshift mutation
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True
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False
Correct Answer
A. TrueExplanation
A frameshift mutation occurs when the addition or deletion of a nucleotide shifts the reading frame of the DNA sequence, resulting in a completely different amino acid sequence being produced during protein synthesis. In this case, the addition of a single nucleotide would disrupt the correct reading frame, leading to a frameshift mutation. Therefore, the statement is true.Rate this question:
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- 7.
In a frameshift mutation, all of the amino acids before the shift are changed.
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True
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False
Correct Answer
A. FalseExplanation
In a frameshift mutation, the insertion or deletion of nucleotides causes a shift in the reading frame of the genetic code. This means that the codons are read incorrectly, leading to a change in the sequence of amino acids in the resulting protein. However, not all of the amino acids before the shift are necessarily changed. Only the amino acids after the shift are affected, while the amino acids before the shift remain the same. Therefore, the statement that all of the amino acids before the shift are changed is false.Rate this question:
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- 8.
What mutational outcome leads to the placement of a different amino acids in a protein?
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Back mutation
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Silent mutation
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Nonsense mutation
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Missense mutation
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Point mutation
Correct Answer
A. Missense mutationExplanation
A missense mutation is a type of point mutation that leads to the placement of a different amino acid in a protein. In this mutation, a single nucleotide change in the DNA sequence results in the substitution of one amino acid with another during protein synthesis. This change can alter the structure and function of the protein, potentially leading to a variety of effects on the organism.Rate this question:
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- 9.
A base substitution that causes regular codon to change in to another codon that codes for a different amino acids is said to be?
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Nonsense mutation
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Silent mutation
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Missense mutation
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None of the above
Correct Answer
A. Missense mutationExplanation
A missense mutation is a type of base substitution that causes a regular codon to change into another codon that codes for a different amino acid. In other words, it leads to a change in the genetic code, resulting in the incorporation of a different amino acid into the protein being synthesized. This mutation can have varying effects on the protein's structure and function, depending on the specific amino acid substitution and its location within the protein.Rate this question:
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- 10.
Addition or deletion of a nucleotide base pair involves
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Point mutation
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Silent mutation
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Nonsense mutation
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Frameshift mutation
Correct Answer
A. Frameshift mutationExplanation
Frameshift mutation occurs when a nucleotide base pair is either added or deleted from the DNA sequence, causing a shift in the reading frame during translation. This results in a completely different amino acid sequence being produced, leading to a nonfunctional or truncated protein. Therefore, frameshift mutation is the correct answer as it accurately describes the consequence of addition or deletion of a nucleotide base pair.Rate this question:
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- 11.
Random mutations occur due to:
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Radiation
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Chemicals
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External facors
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All of the above
Correct Answer
A. All of the aboveExplanation
Random mutations can occur due to radiation, chemicals, and external factors. Radiation, such as UV rays, can cause changes in DNA structure, leading to mutations. Chemicals, such as certain carcinogens, can also damage DNA and cause mutations. Additionally, external factors like viruses or environmental toxins can contribute to random mutations. Therefore, all of the mentioned factors can lead to random mutations.Rate this question:
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- 12.
Point mutations have different effects because of the redundancy of the genetic code
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True
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False
Correct Answer
A. TrueExplanation
Point mutations can have different effects because of the redundancy of the genetic code. The genetic code is degenerate, meaning that multiple codons can code for the same amino acid. Therefore, a point mutation in the DNA sequence may not always result in a change in the amino acid sequence of the protein. This can lead to different effects, such as no change in the protein function or a slight alteration in its structure or function. Thus, the statement that point mutations have different effects due to the redundancy of the genetic code is true.Rate this question:
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- 13.
DNA mutations are random
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True
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False
Correct Answer
A. TrueExplanation
DNA mutations are random because they occur spontaneously and are not influenced by external factors. Mutations can happen during DNA replication, as errors can occur in the copying process. They can also occur due to environmental factors such as radiation or chemicals, but these factors do not determine the specific mutations that will occur. Therefore, mutations are considered random events that can happen at any time in any organism's DNA.Rate this question:
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- 14.
Proof-reading by DNA polymerases occurs through 'backing-up' and removal of incorrect nucleotides
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True
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False
Correct Answer
A. TrueExplanation
The statement is true because proof-reading by DNA polymerases involves a process called "backing-up" where the polymerase enzyme moves backwards on the newly synthesized DNA strand to remove any incorrect nucleotides that were added. This proof-reading mechanism helps to ensure the accuracy of DNA replication by correcting any errors that may have occurred during the synthesis process.Rate this question:
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- 15.
DNA polymerase fixes 100% of incorrect bases
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True
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False
Correct Answer
A. FalseExplanation
DNA polymerase does not fix 100% of incorrect bases. While DNA polymerase does have proofreading capabilities and can correct some errors during DNA replication, it is not perfect. It can still make mistakes and introduce errors into the newly synthesized DNA strand. Additionally, there are other DNA repair mechanisms in the cell that help to fix any errors that DNA polymerase may have missed. Therefore, the statement that DNA polymerase fixes 100% of incorrect bases is false.Rate this question:
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- 16.
Using the molecular record to determine phylogenetic relationships is based on the assumption that
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Nucleotide sequences do not change over time
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Nucleotide sequences change at a fairly constant rate over time
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Nucleotide sequences change randomly and erratically over time
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Evolutionary changes occur in phenotypes but not in genotypes
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All mutations are harmful
Correct Answer
A. Nucleotide sequences change at a fairly constant rate over timeExplanation
The correct answer is that nucleotide sequences change at a fairly constant rate over time. This assumption is the basis for using the molecular record to determine phylogenetic relationships. By comparing the differences in nucleotide sequences between different organisms, scientists can estimate how long ago they diverged from a common ancestor. This assumes that the rate of nucleotide sequence change is relatively constant over time, allowing for the estimation of evolutionary relationships.Rate this question:
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- 17.
Which of the following does not apply when discussing the molecular evidence for evolution:
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Related organisms share a greater portion of their DNAs
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The haemoglobin gene is less similar between humans and dogs than between humans and chimpanzees
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Only DNA can be examined for establishing evolutionary differences
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Molecular evolution progresses more quickly when there is no selection for the gene
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Phylogenetic trees can be established using molecular evidence
Correct Answer
A. Only DNA can be examined for establishing evolutionary differencesExplanation
The statement "Only DNA can be examined for establishing evolutionary differences" is incorrect because molecular evidence for evolution can also be obtained by examining other molecules such as RNA and proteins. These molecules can provide valuable information about evolutionary relationships and patterns.Rate this question:
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Current Version
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Mar 19, 2023Quiz Edited by
ProProfs Editorial Team -
Apr 25, 2016Quiz Created by
Biology16100
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