Biology Microbiology and Biotechnology 1 — Questions and Answers
Question 1: What is the primary purpose of antibiotics?
- To kill viruses
- To kill or inhibit bacteria (Correct answer)
- To boost the immune system
- To provide energy to cells
Correct answer: To kill or inhibit bacteria
Antibiotics are a class of antimicrobial drugs specifically designed to combat bacterial infections. They work by either killing bacteria directly (bactericidal) or inhibiting their growth and reproduction (bacteriostatic), targeting bacterial-specific processes without significantly harming human host cells.
Question 2: Which genetic engineering tool allows precise editing of DNA sequences?
- Polymerase Chain Reaction (PCR)
- CRISPR-Cas9 (Correct answer)
- Gel Electrophoresis
- Southern Blot
Correct answer: CRISPR-Cas9
CRISPR-Cas9 is a revolutionary genetic engineering tool that allows scientists to precisely edit DNA sequences in living organisms. It uses a guide RNA to locate specific DNA targets and a Cas9 enzyme to cut the DNA, enabling the insertion, deletion, or modification of genes with high accuracy and efficiency.
Question 3: What is the main difference between bacteria and viruses?
- Bacteria are non-living; viruses are living.
- Bacteria have cell walls; viruses do not.
- Bacteria reproduce independently; viruses require a host cell. (Correct answer)
- Bacteria can cause diseases; viruses cannot.
Correct answer: Bacteria reproduce independently; viruses require a host cell.
A key distinction is that bacteria are prokaryotic cells capable of independent reproduction through binary fission, possessing their own cellular machinery. Viruses, in contrast, are obligate intracellular parasites; they lack cellular structures and must infect a host cell to hijack its machinery for replication, making them dependent on other organisms to reproduce.
Question 4: What is the purpose of a vaccine?
- To treat infections caused by pathogens
- To boost the body’s production of white blood cells
- To stimulate the immune system to recognize and fight pathogens (Correct answer)
- To kill harmful microorganisms directly
Correct answer: To stimulate the immune system to recognize and fight pathogens
The purpose of a vaccine is to stimulate the immune system to recognize and fight specific pathogens without causing actual illness. By introducing a weakened, inactive, or component part of a pathogen, vaccines prompt the body to produce antibodies and memory cells, preparing it to mount a rapid and effective immune response upon future exposure to the real pathogen.
Question 5: Which microorganism is used in the production of bread and alcoholic beverages?
- Bacteria
- Algae
- Yeast (Correct answer)
- Virus
Correct answer: Yeast
Yeast, specifically *Saccharomyces cerevisiae*, is a single-celled fungus crucial in the production of bread and alcoholic beverages. In bread making, yeast ferments sugars to produce carbon dioxide, which causes the dough to rise, while in brewing, it ferments sugars into ethanol and carbon dioxide, creating alcohol.
Biology Microbiology and Biotechnology 1
What is the primary purpose of antibiotics?