There are Microbiology exam questions and answers in chapter 5.
Question 1: What type of mutation involves the insertion or deletion of a single nucleotide, leading to a shift in the reading frame of the gene?
A) Silent mutation
B) Missense mutation
C) Nonsense mutation
D) Frameshift mutation
Answer: D) Frameshift mutation
Question 2: Which of the following is NOT a cause of mutations?
A) Exposure to mutagenic chemicals
B) Spontaneous errors during DNA replication
C) Repair mechanisms
D) Radiation
Answer: C) Repair mechanisms
Question 3: Which of the following mutations results in a change of a single nucleotide that leads to the substitution of one amino acid in the protein?
A) Silent mutation
B) Nonsense mutation
C) Missense mutation
D) Frameshift mutation
Answer: C) Missense mutation
Question 4: Mutations that occur in somatic cells are responsible for:
A) Genetic diseases passed to offspring
B) The formation of gametes
C) Cancer and certain genetic diseases in the individual
D) None of the above
Answer: C) Cancer and certain genetic diseases in the individual
Question 5: Which type of mutagen is known to cause physical alterations to DNA structure?
A) Chemical mutagen
B) Radiation mutagen
C) Spontaneous mutagen
D) Replicative mutagen
Answer: B) Radiation mutagen
Question 6: A mutation that changes a codon encoding an amino acid to a stop codon is called:
A) Silent mutation
B) Missense mutation
C) Nonsense mutation
D) Frameshift mutation
Answer: C) Nonsense mutation
Question 7: Which repair mechanism specifically targets incorrect base pairs that occur due to errors during DNA replication?
A) Mismatch repair
B) Nucleotide excision repair
C) Base excision repair
D) Direct repair
Answer: A) Mismatch repair
Question 8: Which of the following is an example of a point mutation?
A) Deletion of a large segment of DNA
B) Duplication of a gene
C) Substitution of one nucleotide for another
D) Exchange of genetic material between two chromosomes
Answer: C) Substitution of one nucleotide for another
Question 9: The lac operon is an example of which type of gene regulation?
A) Inducible operon
B) Repressible operon
C) Constitutive operon
D) Nonsense operon
Answer: A) Inducible operon
Question 10: What is the term for the process by which bacteria acquire new genetic material from their environment or from other bacteria?
A) Transduction
B) Transformation
C) Conjugation
D) Replication
Answer: B) Transformation
Question 11: Which of the following is a heritable mutation that occurs in gametes and can be passed on to offspring?
A) Somatic mutation
B) Spontaneous mutation
C) Germline mutation
D) Induced mutation
Answer: C) Germline mutation
Question 12: A mutation that has no detectable effect on the phenotype of an organism is called:
A) Silent mutation
B) Nonsense mutation
C) Missense mutation
D) Frameshift mutation
Answer: A) Silent mutation
Question 13: The Ames test is used to:
A) Detect carcinogens by their mutagenic effects on bacteria
B) Determine the rate of spontaneous mutations
C) Assess the repair mechanisms in DNA
D) Study the impact of frameshift mutations
Answer: A) Detect carcinogens by their mutagenic effects on bacteria
Question 14: Which of the following is a type of mutagenic chemical that mimics a DNA base and can be incorporated into the DNA strand during replication, causing mistakes in base pairing?
A) UV radiation
B) X-rays
C) Intercalating agent
D) Alkylating agent
Answer: C) Intercalating agent
Question 15: A mutation in a gene that leads to the loss of its function is termed:
A) Gain-of-function mutation
B) Nonsense mutation
C) Null mutation
D) Spontaneous mutation
Answer: C) Null mutation
Question 16: The process of DNA repair that involves removing a segment of damaged DNA and replacing it with the correct sequence is known as:
A) Mismatch repair
B) Base excision repair
C) Nucleotide excision repair
D) Direct repair
Answer: C) Nucleotide excision repair
Question 17: What type of mutation occurs when one or more nucleotides are added or deleted from the DNA sequence, causing a shift in the reading frame?
A) Silent mutation
B) Missense mutation
C) Nonsense mutation
D) Frameshift mutation
Answer: D) Frameshift mutation
Question 18: The trp operon is an example of which type of gene regulation?
A) Inducible operon
B) Repressible operon
C) Constitutive operon
D) Nonsense operon
Answer: B) Repressible operon
Question 19: Which repair mechanism involves the direct reversal of DNA damage, such as the removal of alkyl groups from DNA bases?
A) Mismatch repair
B) Base excision repair
C) Nucleotide excision repair
D) Direct repair
Answer: D) Direct repair
Question 20: Mutations in the BRCA1 and BRCA2 genes are associated with an increased risk of:
A) Heart disease
B) Diabetes
C) Breast and ovarian cancer
D) Lung cancer
Answer: C) Breast and ovarian cancer
Question 21: In bacterial conjugation, which structure is responsible for transferring genetic material from the donor bacterium to the recipient bacterium?
A) Plasmid
B) Pilus
C) Capsule
D) Flagellum
Answer: B) Pilus
Question 22: Which type of genetic material is commonly transferred through bacterial conjugation?
A) Chromosomal DNA
B) Ribosomal RNA
C) Mitochondrial DNA
D) Plasmid DNA
Answer: D) Plasmid DNA
Question 23: In conjugation, which bacterium is typically referred to as the “donor” bacterium?
A) The bacterium that receives genetic material
B) The bacterium that donates genetic material
C) A bacterium that remains neutral
D) A bacterium that initiates transformation
Answer: B) The bacterium that donates genetic material
Question 24: What is transduction in bacterial genetics?
A) The direct transfer of genetic material from one bacterium to another
B) The incorporation of foreign DNA into a bacterial genome
C) The transfer of genetic material between bacteria through phages
D) The exchange of genetic material through bacterial conjugation
Answer: C) The transfer of genetic material between bacteria through phages
Question 25: Which of the following is a bacteriophage-mediated transduction process?
A) Transformation
B) Conjugation
C) Horizontal gene transfer
D) Viral vectors transferring DNA
Answer: D) Viral vectors transferring DNA
Question 26: Which of the following is a characteristic of specialized transduction?
A) It involves the transfer of any bacterial genes to a recipient bacterium.
B) It occurs during bacterial conjugation.
C) It results from the accidental packaging of host DNA into a phage particle.
D) It only transfers specific bacterial genes located near the phage integration site.
Answer: D) It only transfers specific bacterial genes located near the phage integration site.
Transformation:
Question 27: What is bacterial transformation?
A) The process of transferring genetic material through pili.
B) The exchange of genetic material between two bacterial cells.
C) The uptake and incorporation of foreign DNA into a bacterial cell.
D) The process of transferring genetic material through bacteriophages.
Answer: C) The uptake and incorporation of foreign DNA into a bacterial cell.
Question 28: Which molecule is crucial for bacterial transformation to occur?
A) Plasmid
B) Capsule
C) Pilus
D) Competence factor
Answer: D) Competence factor
Question 29: What is a competent bacterium in the context of bacterial transformation?
A) A bacterium that has gained resistance to antibiotics.
B) A bacterium that can donate genetic material via conjugation.
C) A bacterium that is able to take up and incorporate foreign DNA.
D) A bacterium that is resistant to phage infection.
Answer: C) A bacterium that is able to take up and incorporate foreign DNA.
Question 30: What is the primary function of the F (fertility) plasmid in bacterial conjugation?
A) To enhance bacterial motility
B) To provide antibiotic resistance to the recipient bacterium
C) To serve as a template for DNA replication
D) To carry the genetic information needed for conjugation
Answer: D) To carry the genetic information needed for conjugation
Question 31: Which bacterial genus is known for its ability to undergo conjugation, leading to the transfer of antibiotic-resistance genes?
A) Escherichia
B) Bacillus
C) Streptococcus
D) Clostridium
Answer: A) Escherichia
Question 32: In generalized transduction, which type of genetic material can be transferred from one bacterium to another?
A) Only plasmid DNA
B) Only chromosomal DNA
C) Any bacterial genetic material, regardless of origin
D) Only transposons
Answer: C) Any bacterial genetic material, regardless of origin
Question 33: Which term refers to the process where bacterial genes located near the integrated phage DNA are transferred to a recipient bacterium via a transducing phage particle?
A) Specialized transduction
B) Generalized transduction
C) Conjugative transduction
D) Fragmented transduction
Answer: A) Specialized transduction
Question 34: In natural transformation, what is required for the bacterial cell to uptake foreign DNA?
A) Contact with a conjugative pilus
B) Physical attachment to a bacteriophage
C) Formation of a F pilus
D) Competence, a physiological state enabling DNA uptake
Answer: D) Competence, a physiological state enabling DNA uptake
Question 35: Which of the following bacterial species is well known for its ability to undergo natural transformation?
A) Staphylococcus aureus
B) Mycobacterium tuberculosis
C) Streptococcus pneumoniae
D) Clostridium botulinum
Answer: C) Streptococcus pneumoniae
Question 36: What term describes the genetic material taken up from the environment by a bacterial cell and incorporated into its genome?
A) Conjugation
B) Transduction
C) Transformation
D) Replication
Answer: C) Transformation
Question 37: Which bacterial group is commonly associated with the ability to transfer antibiotic resistance genes through conjugation?
A) Gram-positive bacteria
B) Acid-fast bacteria
C) Obligate anaerobic bacteria
D) Cyanobacteria
Answer: A) Gram-positive bacteria
Question 38: During bacterial conjugation, which of the following molecules is responsible for the physical connection between donor and recipient bacteria?
A) Plasmid
B) Flagellum
C) Pilus
D) Capsule
Answer: C) Pilus
Question 39: Which type of transduction involves the accidental packaging of host DNA into a phage particle during the lytic cycle?
A) Generalized transduction
B) Specialized transduction
C) Conjugative transduction
D) Directed transduction
Answer: A) Generalized transduction
Question 40: What is the term for a bacterial cell that is susceptible to being infected by a transducing phage and receiving foreign DNA?
A) Lytic cell
B) Non-receptive cell
C) Competent cell
D) Conjugative cell
Answer: C) Competent cell
Question 41: Which discovery is often credited to Frederick Griffith’s experiment using Streptococcus pneumoniae?
A) Bacterial conjugation
B) Bacterial transduction
C) Bacterial transformation
D) Bacterial replication
Answer: C) Bacterial transformation
Question 42: In bacterial transformation, what is the process that involves the uptake of naked DNA fragments from the environment?
A) Uptake and incorporation
B) Transduction
C) Conjugation
D) Uptake and integration
Answer: A) Uptake and incorporation
Question 43: What does the term “competence” refer to in the context of bacterial transformation?
A) The ability of bacteria to produce toxins
B) The capacity of bacteria to replicate their DNA
C) The physiological state enabling bacteria to uptake and incorporate foreign DNA
D) The process of transferring genetic material through pili
Answer: C) The physiological state enabling bacteria to uptake and incorporate foreign DNA
Question 44: What is the basic unit of heredity that carries genetic information?
a) Protein
b) Amino Acid
c) Nucleotide
d) Carbohydrate
Answer: c) Nucleotide
Question 45: Which scientist is known as the “Father of Genetics” for his work on pea plants?
a) Isaac Newton
b) Gregor Mendel
c) Charles Darwin
d) Louis Pasteur
Answer: b) Gregor Mendel
Question 46: What is the term for the specific location of a gene on a chromosome?
a) Allele
b) Locus
c) Genotype
d) Phenotype
Answer: b) Locus
Question 47: A trait that is expressed only when an individual has two identical alleles for a particular gene is called:
a) Dominant trait
b) Recessive trait
c) Co-dominant trait
d) Incomplete dominance
Answer: b) Recessive trait
Question 48: Which genetic disorder is characterized by a missing or non-functional X chromosome in females, leading to developmental and cognitive issues?
a) Down syndrome
b) Hemophilia
c) Turner syndrome
d) Cystic fibrosis
Answer: c) Turner syndrome
Question 48: In a DNA molecule, adenine (A) always pairs with:
a) Thymine (T)
b) Cytosine (C)
c) Guanine (G)
d) Uracil (U)
Answer: a) Thymine (T)
Question 49: What is the term for a change in the DNA sequence of a gene?
a) Mutation
b) Transcription
c) Translation
d) Replication
Answer: a) Mutation
Question 50: The process by which genetic information is copied from DNA to RNA is called:
a) Translation
b) Replication
c) Transcription
d) Transduction
Answer: c) Transcription
Question 51: Which genetic disorder is characterized by an extra copy of chromosome 21, leading to intellectual disabilities and certain physical features?
a) Hemophilia
b) Down syndrome
c) Sickle cell anemia
d) Muscular dystrophy
Answer: b) Down syndrome
Question 52: What is the term for the observable characteristics or traits of an organism?
a) Genotype
b) Phenotype
c) Allele
d) Mutation
Answer: b) Phenotype
Here is the video of Microbiology exam questions and answers pdf chapter 5 (mutation, conjugation, transduction, transformation)