1. A plasmid is a small, circular piece of DNA that exists independently from the bacterial genome. It often carries genes that provide an advantage to the bacterial host, such as antibiotic resistance or the ability to metabolize certain chemicals.
2. DNA replication in bacteria is an enzymatic process that involves the unwinding and separating of the two strands of DNA, followed by the synthesis of new complementary strands using DNA polymerase enzymes. Replication occurs in a semi-conservative manner, with each new daughter cell receiving one old strand and one newly synthesized strand.
3. DNA polymerase is an enzyme that is responsible for synthesizing new strands of DNA during replication, repair, and recombination processes. It adds nucleotides to the growing strand in a precise and efficient manner, ensuring the fidelity of genetic information transfer.
4. Gene expression in bacteria involves the process of transcription, in which messenger RNA (mRNA) is synthesized from a DNA template sequence, followed by translation, in which the mRNA is used to direct the synthesis of a protein.
5. Two important steps in the process of protein synthesis are transcription, in which the DNA sequence is transcribed into mRNA, and translation, in which the mRNA sequence is translated into a protein sequence.
6. Sigma factors are proteins that bind to DNA at specific promoter sequences, marking the start of a new transcription unit. They facilitate the recruitment of RNA polymerase and the initiation of transcription.
7. Translation in bacteria involves the interaction of the mRNA sequence with ribosomes, which move along the mRNA, reading the codons and matching them to the appropriate amino acids using transfer RNA (tRNA). The amino acids are then joined together to form a protein chain.
8. Recombination in bacteria involves the exchange of genetic material between two different DNA molecules, resulting in new combinations of genes. This can occur through processes such as conjugation, transformation, and transduction.
9. Bacteriophages are viruses that specifically infect bacteria. They consist of a protein coat surrounding a nucleic acid core, which contains the viral genome.
10. Two types of bacteriophages are lytic bacteriophages, which cause the death of the host cell upon infection, and lysogenic bacteriophages, which integrate their genome into the host genome and replicate along with it.
11. Conjugation involves the transfer of genetic material between two bacterial cells through a conjugative pilus, while transformation involves the uptake of naked DNA from the environment. Both processes can result in the incorporation of new genetic material into the recipient cell's genome.
12. Spontaneous mutations occur naturally as a result of errors in DNA replication or chemical damage to DNA, while induced mutations are caused by external factors such as radiation or exposure to mutagenic chemicals.
13. Mutagens in bacteria include chemicals such as nitrosoguanidine, UV radiation, and ionizing radiation.
14. Applications of genetics in medicine include genetic testing and counseling for inherited diseases, gene therapy for treatment of genetic disorders, and the development of genetically engineered drugs such as insulin.
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.
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