1.
Diversity in a bacteria can be generated via..
Correct Answer
A. Mutation
Explanation
Mutation is a process that introduces genetic variations in bacteria. It occurs when there is a change in the DNA sequence, resulting in a new trait or characteristic. This can lead to diversity within the bacterial population as different mutations can give rise to different phenotypes. Natural selection, on the other hand, acts upon this diversity by favoring individuals with advantageous traits, leading to the survival and reproduction of those individuals. Gene transfer, while also contributing to genetic diversity, involves the exchange of genetic material between bacteria rather than generating new variations within a single bacterium.
2.
Modification in the sequence of DNA is a gene often resulting in an alteration in the protein encoded gene is known as..
Correct Answer
B. Mutation
Explanation
Mutation refers to a modification in the sequence of DNA, which can occur spontaneously or be induced by external factors. It often leads to changes in the protein encoded by the gene. Therefore, mutation is the correct answer in this case as it accurately describes the process of genetic alteration resulting from changes in DNA sequence.
3.
Define Mutation
Correct Answer
A. Is a change in the existing nucleotide sequence of a cell's DNA which is then passed on to daughter cells
Explanation
Mutation is defined as a change in the existing nucleotide sequence of a cell's DNA. This change can occur due to various factors such as errors during DNA replication or exposure to mutagenic agents. These mutations can be passed on to daughter cells during cell division. Bacteria, in particular, have two general means by which they adapt to new circumstances. One of these means is acquiring genes from another organism, which can also lead to changes in the nucleotide sequence of their DNA.
4.
What are mutations that occur in the cell's natural environment
Correct Answer
C. Spontaneous Mutations
Explanation
Spontaneous mutations are the mutations that occur naturally in the cell's environment without any external factors or influences. These mutations can arise due to errors in DNA replication or as a result of normal cellular processes. Unlike induced mutations, which are caused by external factors such as radiation or chemicals, spontaneous mutations are random and unpredictable. They can lead to genetic variations and contribute to the evolution of organisms.
5.
Spontaneous Mutations are...
Correct Answer
B. Mutations are stable inheritable changes in the base sequence of DNA
Explanation
Spontaneous mutations are stable inheritable changes in the base sequence of DNA. This means that these mutations occur naturally and can be passed on to future generations. These changes in the DNA sequence can have an impact on both the genotype and phenotype of an organism.
6.
Vertical gene transfer
Correct Answer
B. Mutation passed onto progeny: inherited
Explanation
The correct answer suggests that a mutation is passed on to the offspring or progeny. This means that the genetic change or alteration in the DNA sequence is inherited by the next generation. This process is known as vertical gene transfer, where genetic information is transferred from parent to offspring. It is important to note that this answer does not explicitly mention the term "vertical gene transfer," but it conveys the concept by describing the inheritance of mutations.
7.
Reversion are...
Correct Answer
A. Change in a cell's genotype and pHenotype to its original state through a change in the mutated gene
Explanation
Reversion refers to the process in which a cell's genotype and phenotype return to their original state by undergoing a change in the mutated gene. This means that any alterations or mutations that occurred in the gene are reversed, resulting in the cell returning to its original genetic and physical characteristics. This process allows the cell to revert back to its normal state and function.
8.
Spontaneous mutation can occur as a result of what?...
Correct Answer
E. A, C, D are correct
Explanation
Spontaneous mutation can occur as a result of base substitution, removal or addition of nucleotides, and the presence of transposable elements. Base substitution refers to the replacement of one nucleotide with another, which can lead to changes in the genetic code. The removal or addition of nucleotides can cause frameshift mutations, altering the reading frame of the gene. Transposable elements are DNA sequences that can move around within the genome, potentially disrupting genes and causing mutations. Therefore, options A, C, and D are all correct explanations for the occurrence of spontaneous mutations.
9.
Base Substitution are.
Correct Answer
D. A and B are correct
Explanation
The correct answer is A and B are correct. Base substitution is the most common type of mutation, which occurs when there are mistakes during DNA synthesis. This type of mutation involves the replacement of one nucleotide with another, which can lead to changes in the genetic code. Therefore, both statements A and B accurately describe base substitution mutations.
10.
Point Mutations
Correct Answer
A. Occur when on base pair is changed
Explanation
The correct answer is "Occur when one base pair is changed." This explanation is supported by the statement that point mutations are mutations that result from a change in one base pair. This means that a single nucleotide is substituted, inserted, or deleted in the DNA sequence, leading to a change in the genetic code.
11.
Missense mutation
Correct Answer
B. Mutation resulting from amino acid substitution
Explanation
A missense mutation is a type of mutation that occurs when one base pair is changed, resulting in a substitution of one amino acid for another in the protein sequence. This type of mutation does not necessarily lead to inactivation of the gene or a stop codon. Instead, it leads to a change in the amino acid sequence, which can affect the structure and function of the protein.
12.
Nonsense mutation
Correct Answer
C. Mutation that chagnes an amino acid codon to a stop codon
Explanation
A nonsense mutation is a type of mutation that changes an amino acid codon to a stop codon. This means that instead of coding for an amino acid, the mutated codon signals the end of protein synthesis. As a result, the protein being produced is shortened and nonfunctional. This type of mutation can have significant effects on the structure and function of the protein, potentially leading to various genetic disorders or diseases.
13.
Null or knockout mutation
Correct Answer
D. Mutation that inactivates a gene results in a strain that is unable to grow
Explanation
This answer is correct because null or knockout mutations are mutations that result in the inactivation of a gene. When a gene is inactivated, it is unable to produce a functional protein, which can lead to a strain or organism being unable to grow. This type of mutation is often used in genetic studies to understand the function of specific genes by observing the effects of their inactivation.
14.
What does the removal or addition of Nucleotides do?
Correct Answer
D. All of the above are correct
Explanation
The removal or addition of nucleotides can have several effects. It can shift the translation reading frame, causing a frameshift mutation. This means that the codons of the DNA are shifted when it is transcribed into mRNA. Therefore, all of the given options are correct.
15.
What are the effects of a frameshift mutation?
Correct Answer
D. All of the above are correct
Explanation
Read pg. 189 on microbiology book under the section of removla or additon of nucleotides
16.
What are transposable elements
Correct Answer
A. Special segments of DNA that move spontaneoulsy from gene to gene
Explanation
Transposable elements are special segments of DNA that have the ability to move or transpose themselves spontaneously from one location to another within a genome. These elements can "jump" from gene to gene, causing genetic rearrangements and potentially disrupting gene function. They are considered to be mobile genetic elements and can have significant impacts on genome structure and evolution.
17.
Another name for Transposable elements
Correct Answer
B. Transposons
Explanation
Transposons are another name for transposable elements. Transposable elements are DNA sequences that have the ability to move or transpose themselves within the genome. They can be found in both prokaryotes and eukaryotes and can have significant effects on the genome, such as causing mutations or altering gene expression. Transposons are often referred to as "jumping genes" because of their ability to move around the genome.
18.
What happens to the gene after transposon inserts..
Correct Answer
D. Only B and C are correct
Explanation
After a transposon inserts into a gene, the gene can no longer encode a functional protein because the insertion disrupts the gene. This disruption can disrupt the proper function of the gene, making the gene or gene product generally non-functional. Therefore, the correct answer is that only options B and C are correct.
19.
What are induced mutations?
Correct Answer
D. Mutations essentialf or understanding genetics, mutations can be intentioanlly produced to demonstrate function of particular gene or set of gene (mutation induced)
Explanation
The correct answer explains that induced mutations are essential for understanding genetics and can be intentionally produced to demonstrate the function of a specific gene or set of genes. It suggests that induced mutations are a deliberate method used in research to study the effects of genetic changes.
20.
Mutations can be induced via...
Correct Answer
D. All of the above are correct
Explanation
Mutations can be induced through various means, including chemical exposure, transposition (the movement of genetic material within a genome), and radiation. These factors can cause changes in the DNA sequence, leading to genetic mutations. Therefore, the correct answer is "All of the above are correct."
21.
Define chemical Mutagens
Correct Answer
B. Any chemical treatment that alters the hydrogon-bonding properties of a purine or pyrimidine base in the DNA will increase the frequency of mutations as the DNA replicates
Explanation
Chemical mutagens are any chemical treatments that change the hydrogen-bonding properties of a purine or pyrimidine base in DNA. These treatments can lead to an increase in the frequency of mutations as the DNA replicates. This means that the chemical mutagens cause changes in the DNA structure, which can result in genetic mutations. These mutations can have various effects on gene function and can be unintentionally caused by exposure to certain chemicals or intentionally induced for experimental purposes.
22.
What are Base Analogs...
Correct Answer
E. Chemicals that are structurally similar to the nitrogenous bases but have slightly altered base pairing properties (base substitution)
Explanation
Base analogs are chemicals that have a similar structure to the nitrogenous bases found in DNA or RNA, but with slight alterations. These alterations affect the base pairing properties of the analogs, leading to base substitution. In other words, base analogs can replace the original bases in DNA or RNA during replication or transcription. This can result in errors in the genetic code, leading to mutations. Therefore, base analogs are important tools in studying DNA and RNA replication, as well as in understanding the effects of mutations.
23.
What are intercalating agents?
Correct Answer
B. Molecules that insert themselves between adjacent bases, increases the frequency of frameshift mutation
Explanation
Intercalating agents are molecules that can insert themselves between adjacent bases in DNA. This insertion disrupts the normal structure of the DNA molecule and can cause frameshift mutations, which alter the reading frame of the genetic code. These mutations can have significant effects on gene expression and can lead to the production of non-functional gene products. Therefore, intercalating agents are known for increasing the frequency of frameshift mutations.
24.
What is a common intercalating agent?
Correct Answer
E. Ethidium bromide
Explanation
Ethidium bromide is a commonly used intercalating agent in molecular biology. Intercalating agents are molecules that can insert themselves between the base pairs of DNA or RNA, causing the DNA or RNA helix to unwind slightly. Ethidium bromide is particularly useful because it can bind to DNA and fluoresce under ultraviolet light, allowing for easy detection and visualization of DNA in experiments such as gel electrophoresis.
25.
Characteristic of Ethidium Bromide
Correct Answer
C. A and B are both correct
Explanation
Ethidium bromide is a potential carcinogen and is commonly used to stain DNA in gel electrophoresis. It intercalates between DNA base pairs and fluoresces under UV light, allowing for visualization of the DNA bands. Due to its potential carcinogenic properties, it should be handled with caution and appropriate safety measures should be taken when working with it. Therefore, both statements A and B are correct.
26.
Transpositon...
Correct Answer
B. Common procedure used to induce mutation in laboratory
Explanation
The correct answer is "common procedure used to induce mutation in laboratory". This is because the given options are discussing different topics and only the fourth option is related to inducing mutation in a laboratory setting. The other options talk about a random statement, altering hydrogen-bonding properties, and stating that none of the options are correct, which do not align with the given options.
27.
Genes that move from one replicon to another site in the same replicon, or to another replicon on the same cell
Correct Answer
D. Transposon (transposable element)
Explanation
The given answer, transposon (transposable element), is correct because transposons are genetic elements that can move from one location to another within the genome. They can move within the same replicon or to another replicon within the same cell. This movement can lead to changes in the genetic information and can cause insertion mutations. Intercalating agents and alkylating agents are not related to the movement of genes within replicons. The unrelated sentence at the end does not provide any relevant information for the question.
28.
Genes that receives the transposon will undergo a knockout mutation termed?
Correct Answer
A. Insertion mutation
Explanation
An insertion mutation occurs when an extra nucleotide or sequence of nucleotides is inserted into the DNA sequence, disrupting the normal gene function. In this case, the transposon is inserted into the gene, causing a knockout mutation. The other options, silent mutation, point mutation, and nonsense mutation, do not involve the insertion of extra nucleotides and do not accurately describe the given scenario.
29.
Name two type of Radiaton in Induced Mutations
Correct Answer
E. Both A and C are correct
Explanation
The correct answer is both A and C are correct. X rays and ultraviolet light are both types of radiation that can induce mutations. X rays are a form of ionizing radiation that can cause DNA damage and mutations. Ultraviolet light, specifically UVB and UVC rays, can also cause DNA damage and mutations by forming thymine dimers in the DNA molecule. Therefore, both A (X rays) and C (ultraviolet light) are correct types of radiation in induced mutations.
30.
Define Ultraviolet light * (please choose three of the correct answers)
Correct Answer(s)
A. Causes covalent bonding between adjacent thymine bases
C. Forms thymine dimers which distorts DNA
E. Prevents replication past the dimer (SOS repair system results in the incorporation of the wrong bases)
Explanation
Ultraviolet light causes covalent bonding between adjacent thymine bases, which can lead to the formation of thymine dimers. These dimers distort the structure of DNA. Additionally, the presence of thymine dimers prevents replication of DNA past the dimer, and the SOS repair system may result in the incorporation of incorrect bases during replication.
31.
Define X-rays (please choose two of the correct answer)
Correct Answer(s)
B. Causes single and double stranded breaks in DNA, and alterations to the bases
D. Breaks that occur on both strands are often lethal or Double-strand breaks often result in deletions that are lethal
Explanation
X-rays cause single and double stranded breaks in DNA, which can lead to alterations in the bases. These breaks can be lethal, and double-strand breaks often result in deletions that are also lethal. This damage to DNA can have serious consequences for cell function and can potentially lead to cell death or genetic mutations.
32.
Major problem in induced mutation is identifying bacteria with desired mutation, name the techniques used...
Correct Answer
D. Both A and C are correct
Explanation
Both direct selection and mutagenesis are techniques used to identify bacteria with desired mutations. Direct selection involves directly selecting the bacteria that exhibit the desired mutation, while mutagenesis involves inducing random mutations in bacteria and then selecting those with the desired mutation. Therefore, both options A and C are correct.
33.
Define Direct Selection...
Correct Answer
C. Involves inoculating population of bacteria on medium on which only mutants but not the parent, will grow/ used to select antimicrobial resistant or auxotropHic mutants reverted to prototropHic organisms
Explanation
Direct selection involves inoculating a population of bacteria on a medium where only mutants, but not the parent strain, will grow. This method is used to isolate organisms that require growth factors that the parent strain does not have. It is also used to select antimicrobial resistant or auxotrophic mutants that have reverted back to prototrophic organisms. Replica plating is not the correct answer as it refers to a different technique.
34.
Indirect selection...
Correct Answer
A. Is required to isolate organsisms that require growth factor that parent strain does not have (auxotropHic mutants)/ replica plating
Explanation
Indirect selection, specifically replica plating, is a technique used to isolate organisms that require a growth factor that the parent strain does not have, known as auxotrophic mutants. This involves inoculating cells onto a medium on which the mutant, but not the parent, can grow. By comparing the growth patterns of the cells on different media, mutants that can grow under conditions in which the parent cells cannot are easily identified and isolated. Therefore, both options A and B are correct.
35.
Testing for cancer causing chemical (carcinogens), many mutagens are also carcinogens, microbes used to test potential carcinogenic activity, test are based on effect chemicals has on mibrobial DNA. What is a common chemical carcinogen test?
Correct Answer
C. Ames Test
Explanation
The Ames Test is a common chemical carcinogen test. It is used to determine the potential carcinogenic activity of a substance by observing its effect on the DNA of microbes. Since the question states that many mutagens are also carcinogens, the Ames Test is an appropriate method to assess the carcinogenicity of chemicals. Therefore, the correct answer is Ames Test.
36.
Ames test (check all that are correct/ more than one can be correct)
Correct Answer(s)
A. Test assumes that the frequency of reversions is increaed by mutagens and that most carcinogens are mutagens
B. Test rate of reversion of Salmonella auxotropH/ test potential lethality
Explanation
D cannot be correct because it was devised by Bruce Ames and his colleagues in 1960's not 1970 :O
37.
Genes transferred from one cell to another...
Correct Answer
C. Horizontal gene transfer
Explanation
Horizontal gene transfer refers to the transfer of genetic material from one organism to another that is not its offspring. This transfer can occur between organisms of the same species or different species. It is called "horizontal" because the transfer happens sideways, between individuals that are not directly related. This process plays a significant role in the evolution and adaptation of organisms, as it allows for the spread of beneficial traits and genetic diversity throughout a population.
38.
Genes are naturally transferred between bacteria using mechanisms what are the mechanisms?
Correct Answer
D. All of the above are correct
Explanation
Genes can be naturally transferred between bacteria through three mechanisms: DNA-mediated transformation, transduction, and conjugation. In DNA-mediated transformation, bacteria take up free DNA from the environment and incorporate it into their own genome. Transduction involves the transfer of genes between bacteria via viruses. Conjugation is the direct transfer of genetic material from one bacterium to another through a physical connection. Therefore, all of the above mechanisms are correct for the natural transfer of genes between bacteria.
39.
Involves the transfer of naked DNA from the environment to the recipent cell, cells rupture during the stationary and death phase, the chromosome breaks into small pieces and explodes through the ruptured cell wall, recipeitn "competent" cell picks up piece of the naked DNA, the naked DNA is integrated onto the recipeint chromosome, (replaces the homologous gene on the cromose to the recipeint cell). What type mechanisms of Gene transfer is that?
Correct Answer
B. DNA-Mediated transformation
Explanation
The given mechanism of gene transfer involves the transfer of naked DNA from the environment to the recipient cell. This DNA is integrated onto the recipient chromosome, replacing the homologous gene. This process is known as DNA-Mediated transformation.
40.
DNA-mediated transformation; natural transformation occurs when bacterial cells are compentent, bacterial cells are capable of taking up and integrating larger fragments of DNA. Natural transformtion occurs in stages what are they. (choose all that apply)
Correct Answer(s)
A. Entry of the DNA
B. Integrationof the donor DNA
C. Mismatch Repair
D. Cell Multiplication
41.
In Natural transformation this "stage"... only single strands enter, double strands are degraded
Correct Answer
B. Entry of the DNA
Explanation
The correct answer is "Entry of the DNA". In natural transformation, the process involves the uptake of DNA from the environment by a recipient cell. During this stage, only single strands of DNA enter the cell, while double strands are degraded. This allows for the integration of the donor DNA into the recipient cell's genome, leading to cell multiplication and potential genetic changes. Mismatch repair and SOS repair are other processes that occur after the DNA has entered the cell.
42.
In Natrural transformation this "stage"... donor DNA is integrated by hydrogen bonding, enzymes cleave recipient DNA, Donor DNA is put in place
Correct Answer
B. Integration of the Donor DNA
Explanation
The correct answer is Integration of the Donor DNA. In natural transformation, the donor DNA is integrated into the recipient DNA through hydrogen bonding. This process allows for the incorporation of new genetic material into the recipient cell's genome. Once integrated, the donor DNA can be expressed and contribute to the functioning of the recipient cell.
43.
In Natural transformation this "stage"... repair mechanism removes either donor or recipient DNA that doesn't match, repairs with correct nucleotides
Correct Answer
B. Mismatch repair
Explanation
Mismatch repair is the correct answer because it is a repair mechanism in natural transformation that removes either donor or recipient DNA that doesn't match and repairs it with the correct nucleotides. This repair mechanism ensures that any mismatches or errors in the DNA are corrected, leading to the successful integration of the donor DNA into the recipient cell.
44.
In Natural transformation this "stage"... transformed cells multiply under selective conditions in which non-transfored cells will not grow
Correct Answer
A. Cell multiplication
Explanation
Cell multiplication refers to the process in which cells divide and replicate to form new cells. In the context of natural transformation, this stage is important because it allows the transformed cells (cells that have taken up foreign DNA) to multiply under selective conditions. Non-transformed cells, on the other hand, will not be able to grow under these conditions. Therefore, cell multiplication is crucial for the survival and propagation of the transformed cells in natural transformation.
45.
Mechanisms of Gene Transfer... Bacterial DNA that is transferred from donor to recipeint via a bacterial virus (bacteriophage)
Correct Answer
B. Transduction
Explanation
Transduction is a mechanism of gene transfer in bacteria where bacterial DNA is transferred from a donor to a recipient via a bacterial virus known as a bacteriophage. During transduction, the bacteriophage infects a bacterial cell and incorporates the bacterial DNA into its own viral DNA. When the virus infects another bacterial cell, it transfers the bacterial DNA, leading to the transfer of genetic material between bacteria. This mechanism plays an important role in horizontal gene transfer and the spread of antibiotic resistance genes among bacteria.
46.
Is a mispackaging of DNA during viral replication, the mis-packaged phage infects a new bacterial cell and inserts the donor DNA inot the recipient cell, the donor DNA is integrated into the cell by homologous recombination. Is what type of mechanisms of gene transfer?
Correct Answer
A. Transduction
Explanation
The given scenario describes the process of transduction, where a mispackaged phage (virus) infects a bacterial cell and transfers donor DNA into the recipient cell. This transfer of genetic material is facilitated by the phage and is achieved through the mechanism of transduction. Transduction is a type of gene transfer mechanism commonly observed in bacteriophages, where they can transfer DNA between bacterial cells during infection.
47.
Mechanisms of Gene transfer; only form ofgene exchagne in which donor survives
Correct Answer
D. Conjugations
Explanation
Conjugation is the only form of gene exchange in which the donor survives. In conjugation, genetic material is transferred from one bacterial cell to another through a direct physical connection called a pilus. The donor cell, which contains the plasmid carrying the desired gene, survives the transfer process and continues to replicate. This is in contrast to other mechanisms like transduction, where genetic material is transferred through a viral vector, or DNA-mediated transformation, where DNA is taken up from the environment. In both of these mechanisms, the donor cell does not necessarily survive the transfer.
48.
Conjuagtion is mediated by a plasmid
Correct Answer
A. True
Explanation
Conjugation is a process of genetic transfer in bacteria where genetic material is transferred between two cells through direct contact. This transfer is facilitated by a plasmid, which is a small, circular DNA molecule that can replicate independently of the bacterial chromosome. The plasmid carries the genes necessary for conjugation, including those involved in the formation of a conjugation pilus and the transfer of DNA. Therefore, the statement that conjugation is mediated by a plasmid is true.
49.
Plasmid is self replication extrachromosomal piece of DNA (can code for traits that give bacteria advantage)
Correct Answer
A. True
Explanation
A plasmid is a small, circular, self-replicating piece of DNA that exists outside of the bacterial chromosome. Plasmids can carry genes that provide advantages to bacteria, such as antibiotic resistance or the ability to produce certain enzymes. This allows bacteria to adapt and survive in different environments. Therefore, the statement that plasmids are self-replicating extrachromosomal pieces of DNA that can code for traits that give bacteria an advantage is true.
50.
Conjugation requires direct contact between cells, cells must be of opposite mating types
Correct Answer
A. True
Explanation
Conjugation is a process of genetic transfer in bacteria that requires direct contact between cells. The cells involved in conjugation must be of opposite mating types, meaning they have different genetic information. This ensures that the genetic material being transferred is diverse and can contribute to the genetic variability of the population. Therefore, the statement that conjugation requires direct contact between cells and cells must be of opposite mating types is true.