A Basic Trivia Quiz On Microbiology

A virus is a microscopic infectious agent that consists of genetic material (DNA or RNA) enclosed in a protein coat called a capsid. The capsid protects the genetic material and helps the virus to attach to and infect host cells. Therefore, the correct answer is "capsid."

Oncogenic viruses are viruses that have the ability to cause cancer. These viruses can infect cells and alter their genetic material, leading to uncontrolled cell growth and the development of tumors. Examples of oncogenic viruses include human papillomavirus (HPV), hepatitis B virus (HBV), and Epstein-Barr virus (EBV). These viruses are capable of transforming normal cells into cancer cells and are therefore referred to as oncogenic viruses.

All of the options mentioned are methods of growing animal viruses in the laboratory. Live animals can be used as hosts for the viruses to replicate and grow. Embryonated eggs provide a controlled environment for virus growth and can be used to study the effects of the virus on the developing embryo. Cell culture involves growing animal cells in a laboratory setting, providing an environment for viruses to infect and replicate. Therefore, all of these methods are valid ways to grow animal viruses in the laboratory.

Latent viruses are those that infect a cell without causing symptoms. These viruses remain dormant within the host cell and can reactivate later to cause symptoms. This is in contrast to lytic viruses, which cause immediate cell death and symptoms upon infection. Lysogenic viruses integrate their genetic material into the host cell's DNA and can remain dormant for long periods before becoming lytic. Persistent viruses continuously produce low levels of viral particles without causing immediate symptoms. Therefore, the correct answer is latent viruses.

The lysogenic cycle is responsible for transduction. During this cycle, the bacteriophage inserts its genetic material into the host bacterium's DNA, becoming a prophage. The host bacterium then replicates the prophage along with its own DNA during cell division. As a result, the viral genetic material is passed on to daughter cells. Transduction occurs when the prophage excises itself from the bacterial DNA and carries some of the bacterial genes with it. These genes can then be transferred to another bacterium, leading to genetic recombination.

An enveloped virus would use spikes for attachment. Spikes are protein structures that protrude from the viral envelope and help the virus attach to host cells. These spikes bind to specific receptors on the surface of the host cell, allowing the virus to enter and infect the cell. The capsid is the protein coat that protects the virus's genetic material, while tail fibers and flagella are typically found in non-enveloped viruses and serve different functions such as host recognition or movement.

In the lysogenic cycle, the phage DNA is incorporated into the host cell DNA. This means that the viral DNA becomes a part of the host cell's genetic material and is replicated along with it. This integration allows the viral DNA to be passed on to daughter cells during cell division. In contrast, the lytic cycle involves the cell bursting during release of new viral particles, phages typically contain DNA genomes (not RNA), and there is a latent period where the viral DNA is not actively replicating.

A prion is an infectious protein that can cause diseases in animals and humans. Unlike viruses or bacteria, prions do not contain genetic material and are composed solely of misfolded proteins. These misfolded prion proteins can convert normal proteins into the abnormal form, leading to the accumulation of these misfolded proteins in the brain and nervous system. This accumulation disrupts normal cellular processes and causes neurodegenerative diseases, such as Creutzfeldt-Jakob disease and mad cow disease. Therefore, prions are considered infectious agents due to their ability to transmit disease through the misfolding of proteins.

The term "host range" refers to the spectrum of cells that a virus can infect. It represents the variety of host organisms or cell types that a virus is capable of infecting and replicating within. The host range can vary greatly among different viruses, with some being highly specific and only infecting a limited range of hosts, while others have a broader host range and can infect a wide variety of organisms.

A virion refers to a complete, infectious virus particle. It includes the genetic material (DNA or RNA) surrounded by a protein coat called the capsid. The virion is capable of infecting a host cell and replicating itself, leading to the spread of the virus.

Most viruses do not have a broad host range. Viruses are highly specific and can only infect certain types of cells or organisms. They often have specific receptors on their surface that can only bind to certain molecules on the host cell's surface. This specificity is why different viruses cause different diseases in different organisms. So, the statement that most viruses have a broad host range is false.

Viroids are naked pieces of infectious RNA. Unlike viruses, they do not have a protein coat or a lipid envelope. Viroids are smaller than viruses and are composed solely of a single-stranded RNA molecule. They are known to infect plants and cause various diseases, interfering with the normal functioning of the host plant's cells. Prions, on the other hand, are infectious proteins and not RNA-based. Virions are complete virus particles, which can contain DNA or RNA, while phages are viruses that infect bacteria.

PCR, or polymerase chain reaction, is a laboratory technique used to amplify a specific DNA sequence. It is not a means of identifying viruses because it does not directly detect the presence of a virus or its characteristics. PCR is used to replicate and amplify the viral DNA or RNA, which can then be further analyzed or tested using other methods for identification.

When a virus enters a cell, it must shed its protein coat and release its nucleic acid into the host cell in order to initiate infection and replication. This process is known as uncoating. During uncoating, the virus disassembles and exposes its genetic material, allowing it to take control of the host cell's machinery and replicate itself.

Phage conversion refers to the process in which a bacterium acquires new properties or abilities as a result of the presence of a prophage, which is a viral genome integrated into the bacterial chromosome. This integration can lead to the transfer of genetic material from the prophage to the bacterium, resulting in the expression of new traits. Therefore, the correct answer is phage conversion.

Ribosomes are used for phylogeny in prokaryotic cells because they are essential for protein synthesis. Ribosomes are present in all prokaryotic cells and their structure and function are highly conserved across different species. By comparing the similarities and differences in ribosomal RNA (rRNA) sequences, scientists can determine the evolutionary relationships and phylogeny of different prokaryotic organisms. Therefore, ribosomes serve as important molecular markers for studying the evolutionary history of prokaryotes.

Bacteriophages and animal viruses do not differ significantly in the step of biosynthesis. Biosynthesis refers to the process of viral genetic material being replicated and viral proteins being synthesized within the host cell. Both bacteriophages and animal viruses undergo this step similarly, utilizing the host cell's machinery to produce new viral components.

Western blotting is a technique used to detect specific proteins in a sample, not nucleic acids. It involves separating proteins by gel electrophoresis, transferring them to a membrane, and then using specific antibodies to detect the target protein. Nucleic-acid hybridization techniques, such as DNA chip, FISH, and Southern blotting, are used to detect and analyze specific nucleic acids, such as DNA or RNA, through the process of hybridization.

An oncogene is a gene that is part of the human genome and has the potential to cause cancer. These genes can become mutated or activated, leading to uncontrolled cell growth and the development of tumors. Oncogenes play a crucial role in the initiation and progression of various types of cancer. They can be inherited or acquired through environmental factors, and their activation or mutation can disrupt normal cellular processes, leading to the development of cancerous cells.