Bacteria (VSAQs)
Botany-2 | 7. Bacteria – VSAQs:
Welcome to “VSAQs” in “Chapter 7: Bacteria”. This page covers the most important VSAQs from previous exams. Use these concise answers to strengthen your understanding and get ready to do well in your final exams.
VSAQ-1: Write briefly on the occurrence of microorganisms.
Microorganisms, such as bacteria and viruses, are incredibly diverse and can be found in virtually every environment on Earth. They thrive in a wide range of conditions, from the hot springs of Yellowstone National Park to the icy expanses of Antarctica. You can find them not only in extreme environments but also in more familiar places like the soil in your garden, the air we breathe, and even inside our own bodies. For instance, the bacteria in our digestive system help break down food, demonstrating how microorganisms are an integral part of many processes essential for life.
VSAQ-2: Define microbiology.
Microbiology is a specialized field of biological science that focuses on studying microorganisms. These tiny organisms include bacteria, viruses, protozoans, and sometimes certain fungi and algae. Microbiologists use microscopes to observe and understand these organisms, which are often too small to see with the naked eye. For example, when a scientist studies how a virus spreads or how bacteria interact with their environment, they rely on microbiology to gain insights that can lead to medical breakthroughs or new technological advancements.
VSAQ-3: Name the bacteria that is a common inhabitant of the human intestine. How is it used in biotechnology?
One of the most well-known bacteria living in the human intestine is Escherichia coli, commonly known as E. coli. Most strains of E. coli are harmless and actually help with digestion, but some can cause illness. Beyond its role in our gut, E. coli is also a star in the world of biotechnology. In labs, scientists use E. coli to produce a variety of useful products. For example, it serves as a host for recombinant DNA technology, where researchers insert new genes into E. coli to create proteins like insulin for diabetes treatment. This bacterium’s ability to replicate quickly and handle genetic modifications makes it an essential tool in scientific research and industry.
VSAQ-4: What are pleomorphic bacteria? Give an example.
Pleomorphic bacteria are unique because they can change their shape in response to different environmental conditions or nutrient availability. Unlike most bacteria that have a fixed shape, pleomorphic bacteria can adapt their form to survive in various situations. A good example is Acetobacter, a bacterium that plays a crucial role in the production of vinegar. Acetobacter can alter its shape depending on the conditions, which helps it thrive in acidic environments where vinegar is produced. This ability to change form allows pleomorphic bacteria to adapt and survive in fluctuating conditions, showcasing their remarkable versatility.
VSAQ-5: What is sex pilus? What is its function?
The sex pilus is a fascinating structure found in some bacteria, often referred to as the conjugation tube. This tiny, hair-like extension acts like a bridge between two bacterial cells. During a process known as bacterial conjugation, a donor cell, marked as F+, uses the sex pilus to connect with a recipient cell, called F-. The primary function of the sex pilus is to transfer genetic material, such as plasmids, from the donor to the recipient. This exchange of genetic information allows bacteria to acquire new traits, like antibiotic resistance or the ability to metabolize new nutrients. By facilitating this genetic exchange, the sex pilus helps bacteria adapt quickly to environmental changes, enhancing their survival and evolution.
VSAQ-6: What is a genophore?
A genophore, also known as the bacterial chromosome, is the key piece of genetic material inside bacteria. Imagine it as the instruction manual for the bacterium’s life. It is made up of a single, circular strand of DNA that carries all the essential genetic information needed for the bacterium’s growth, development, and reproduction. Just like how your personal traits are influenced by your genes, the genophore determines the traits and functions of the bacterium. It contains the genes that instruct the bacterium on how to perform various tasks and maintain its functions. For example, the genophore includes the instructions for producing proteins that help the bacterium survive in its environment.
VSAQ-7: What is a plasmid? What is its significance?
A plasmid is a small, circular piece of DNA that exists independently of the genophore in bacteria and some other organisms. Unlike the genophore, which contains the essential genetic information for survival, plasmids can replicate on their own and often carry extra genetic information. Think of plasmids as bonus instruction manuals that can provide additional features or abilities to the bacterium. For instance, plasmids might carry genes that give bacteria the ability to resist antibiotics.
The importance of plasmids shines in the field of genetic engineering. Scientists use plasmids as tools, or vectors, to introduce new genes into bacteria. This process allows them to produce useful substances like medicines, study how genes work, and perform various biotechnological tasks. For example, plasmids are used to insert a gene into bacteria that will make them produce insulin, a crucial hormone for managing diabetes.
VSAQ-8: What is conjugation? Who discovered it and in which organism?
Conjugation is a fascinating process where two bacterial cells exchange genetic material through direct contact. Picture it as a form of bacterial social interaction where one cell shares some of its genetic information with another. This process was first observed by Joshua Lederberg and Edward Tatum in the bacterium Escherichia coli. Their discovery in the 1940s revealed how bacteria could swap genetic traits, which was a breakthrough in understanding how bacteria share and spread genes. This mechanism is crucial for bacterial evolution and adaptation.
VSAQ-9: What is transformation? Who discovered it and in which organism?
Transformation is when bacteria take up naked DNA from their environment and integrate it into their own genetic material. Imagine it as a bacterium picking up new genetic “recipes” from the surroundings. This process was first discovered by Frederick Griffith while working with Streptococcus pneumoniae in the 1920s. Griffith’s experiments, which included using mice, showed that bacteria could acquire new traits by absorbing DNA from other bacteria. This discovery laid the foundation for the field of bacterial genetics and opened doors to understanding how genetic information can be exchanged and utilized by bacteria.
VSAQ-10: What is transduction? Who discovered it and in which organism?
Transduction is a process where genetic material is transferred from one bacterium to another with the help of a bacteriophage—a virus that infects bacteria. Imagine a virus acting like a courier, delivering genetic material from one bacterium to another. This mechanism was discovered by Joshua Lederberg and Norton Zinder in the bacterium Salmonella typhimurium during the 1950s. Their work unveiled how viruses could facilitate genetic exchange among bacteria, contributing significantly to our understanding of bacterial genetics and evolution. This discovery highlighted the role of viruses in the transfer of genetic information, further enriching the field of microbiology.