Write TRUE OR FALSE in the following QUESTIONS
1. Plasmid is usually transferred by conjugation__
2. Protein synthesis may sometimes not involve transcription and translation of the genetic
information__
3. Transduction is one way of transferring genetic material from one bacterium to
another___
4. Bacteriophages are classified based on their interaction with a bacteria
cell__
5. Virulent phages do not multiply or lyse their host cell after infection___
6. Chemical, physical or biological agents can increase the rate of mutation.__
7. Base analogous incorporated into polypeptides chain during replication do not act like
normal bases___
1. True
2. False
3. True
4. True
5. False
6. True
7. True
Cycle or Choose the correct answer below.
1. Can carry genes for antibiotic resistance, resistance to toxic metals, metabolism of
unusual food sources, and pathogenesis genes
a. Plasmid
b. mRNA
c. tRNA
d. All of the above
2. It’s a process that is necessary for cell division to make an exact copy of the DNA
genome for each daughter cell
a. DNA polymerase
b. DNA replication
c. RNA polymerase
d. Replication forks
3. It’s an enzyme that makes an RNA copy from the DNA template
a. DNA polymerase
b. Enzymes in Sigma factors
c. RNA polymerase
d. None of the above
4. The transferring of genetic material from one bacterium to another, is called
a. Gene replication
b. Gene translation
c. Gene recombination
d. Gene shift
5. It’s the transfer of gene from a donor cell to a recipient by way of a bacteriophage
a. Transduction
b. Conjugation
c. Transformation
d. Gene transfer
6. It is an inheritable change in genetic material
a. Haploid
b. Nucleoside
c. Mutation
d. Tandem shift
7. A mutation that occurs in the absence of mutagen
a. Spontaneous
b. Induced
c. Both A and B
d. None of the above
1. a. Plasmid
2. b. DNA replication
3. c. RNA polymerase
4. c. Gene recombination
5. a. Transduction
6. c. Mutation
7. a. Spontaneous
1. Define plasmid in relation to bacterial genome?
2. Explain DNA replication process of the bacterial genome.
3. What is the use of DNA polymerase?
4. Explain gene expression in bacteria?
5. Mention two important steps in the process of protein synthesis.
6. Explain the function of sigma factor during DNA transcription.
7. Explain how translation of genetic information happens in bacteria.
8. Define recombination in bacteria?
9.Define bacteriophage?
10. Mention two types of bacteriophages.
11. Contrast conjugation and transformation as the processes of gene recombination in
bacteria cells.
12. Differentiate spontaneous from induced mutations.
13. Give three examples of mutagens in bacteria.
14. Mention any three examples of application of genetics in medicine.
1. Plasmid is a small, circular piece of extrachromosomal DNA that is separate from the bacterial genome and can replicate independently. It can carry non-essential genes such as those for antibiotic resistance, metabolic pathways, and virulence factors that can provide selective advantages to the bacterium in certain conditions.
2. DNA replication is the process by which a cell makes an exact copy of its genome before cell division occurs. In bacteria, this process starts at a specific point in the genome called the origin of replication. Two replication forks form at the origin and move in opposite directions around the circular chromosome, unwinding the DNA and synthesizing new strands using the existing strands as templates. DNA polymerase and other enzymes are involved in this process to ensure accuracy and fidelity of the copied DNA sequence.
3. DNA polymerase is an enzyme involved in DNA replication that binds to DNA strands to synthesize new strands using the existing strands as templates. It ensures accuracy and fidelity of the newly synthesized DNA by proofreading and correcting any errors that may arise during replication.
4. Gene expression in bacteria involves two major steps: transcription and translation. During transcription, RNA polymerase binds to the promoter region of a gene and synthesizes a complementary mRNA molecule using the DNA strand as a template. The mRNA molecule is then translated into a protein by ribosomes during translation.
5. Two important steps in the process of protein synthesis are transcription and translation. Transcription is the process by which RNA polymerase synthesizes a complementary mRNA molecule using the DNA strand as a template. Translation is the process by which ribosomes read the mRNA sequence and synthesize a protein using amino acids carried by tRNA molecules.
6. Sigma factor is a protein that binds to RNA polymerase to form the holoenzyme, which initiates transcription at the promoter region of a gene. It helps RNA polymerase to recognize the promoter region and to bind to it, ensuring that transcription occurs at the correct site and in the correct orientation.
7. Translation of genetic information in bacteria occurs at ribosomes, which bind to the mRNA molecule and read the sequence of nucleotides. Each codon, or three nucleotides, corresponds to a specific amino acid, which is carried by tRNA molecules to the ribosome. The ribosome then catalyzes the formation of peptide bonds between the amino acids, resulting in the synthesis of a protein.
8. Recombination in bacteria refers to the process by which DNA from two different sources is combined into a single genome. This can occur through genetic exchange mechanisms such as transformation, conjugation, and transduction. During recombination, genetic material is exchanged, and new combinations of genes can emerge, leading to genetic diversity in bacterial populations.
9. Bacteriophage is a virus that infects bacteria, using the bacterial cell machinery to replicate itself.
10. Two types of bacteriophages are lytic and lysogenic. Lytic bacteriophages infect bacteria and cause them to lyse or burst open, releasing new phages into the environment to infect other bacteria. Lysogenic bacteriophages integrate their DNA into the bacterial chromosome and replicate passively with the bacterial genome, only becoming lytic when activated by certain stimuli.
11. Conjugation involves the transfer of genetic material from a donor cell to a recipient cell using a conjugation pilus, while transformation involves the uptake of free DNA from the environment by a bacterial cell. Conjugation requires cell-to-cell contact, and the transferred DNA is often carried on a plasmid, while transformation requires the uptake and integration of extraneous DNA into the bacterial chromosome.
12. Spontaneous mutations occur naturally due to errors in DNA replication or other cellular processes such as DNA damage and repair, while induced mutations are caused by exposure to mutagenic agents such as chemicals, radiation, or viruses.
13. Three examples of mutagens in bacteria are ultraviolet radiation, chemical carcinogens such as nitrous acid, and certain types of transposons that cause insertional mutagenesis.
14. Three examples of applications of genetics in medicine are genetic screening for disease risk, gene therapy for genetic disorders, and pharmacogenomics to personalize drug treatments based on individuals' genetic makeup.
1. True.
2. False.
3. True.
4. True.
5. False.
6. True.
7. False.
1. True - Plasmid is usually transferred by conjugation, which is a process where genetic material is transferred between bacterial cells through direct contact.
2. False - Protein synthesis always involves transcription and translation of the genetic information. Transcription converts the DNA sequence into mRNA, which is then translated into a protein.
3. True - Transduction is a process in which genetic material is transferred from one bacterium to another through a bacteriophage (a virus that infects bacteria) acting as a carrier.
4. True - Bacteriophages are classified based on their interaction with a bacteria cell, such as whether they are lytic (causing cell lysis) or lysogenic (integrating their genetic material into the bacterial genome).
5. False - Virulent phages are able to multiply within the host cell and eventually lyse (break open) the cell to release new phages.
6. True - Chemical, physical, or biological agents can indeed increase the rate of mutation. For example, exposure to certain chemicals or radiation can cause changes in DNA sequences, leading to mutations.
7. False - Base analogs incorporated into a polypeptide chain during replication can act like normal bases, but they can also introduce errors or mutations if they are not recognized properly by the DNA replication machinery.