1.
What is commensalism?
Correct Answer
A. Interaction in which one organism benefits and the host is unaffected
Explanation
Commensalism is an interaction in which one organism benefits while the host remains unaffected. In this type of relationship, the organism that benefits may use the host for resources or shelter without causing harm or receiving any benefit in return. The host neither benefits nor is harmed by the interaction. This type of relationship is commonly observed in nature, where one organism benefits while the other is neither helped nor harmed.
2.
What is mutualism?
Correct Answer
B. E.coli in the gut
Explanation
Mutualism is an interaction in which both organisms involved benefit from the relationship. In the case of E.coli in the gut, it is an example of mutualism because E.coli benefits by obtaining nutrients and a suitable environment for growth, while the host organism (the gut) also benefits from E.coli's production of certain vitamins and its role in digestion.
3.
Prions cause what?
Correct Answer
C. Spongiform encepHalopathies
Explanation
Prions are misfolded proteins that can cause spongiform encephalopathies, a group of neurodegenerative diseases. These diseases are characterized by the accumulation of abnormal prion proteins in the brain, leading to the formation of sponge-like holes and the progressive loss of brain function. Examples of spongiform encephalopathies include Creutzfeldt-Jakob disease, variant Creutzfeldt-Jakob disease, and kuru. Prions do not cause HPV, hepatitis, or avian flu.
4.
Transmissable neurodegenerative diesease that is slow, irreversible, progressive neuronal degeneration that is transmitted via ingestion of infected neuronal tissue is?
Correct Answer
D. All of the above
Explanation
All of the options listed (Kuru, Creutzfeldt-Jakob Disease, Scrapie) are transmissible neurodegenerative diseases characterized by slow, irreversible, progressive neuronal degeneration. These diseases can be transmitted through the ingestion of infected neuronal tissue. Therefore, the correct answer is "All of the above."
5.
Kuru is thought to be transmitted by?
Correct Answer
B. Cannabalism
Explanation
Kuru is a rare and fatal neurodegenerative disease that was prevalent among the Fore people in Papua New Guinea. It was primarily transmitted through cannibalistic practices, where the consumption of infected brain tissue led to the spread of the disease. The disease was often seen in individuals who participated in mortuary feasts where they consumed the brains of deceased relatives. This practice allowed the infectious prion proteins to enter the body, leading to the development of kuru.
6.
Creutzfeld-Jakob Disease is transmitted the most by?
Correct Answer
C. Sporadic unknown
Explanation
85% sporadic sCJD
7.
A virus can be oncogenic?
Correct Answer
A. True
Explanation
A virus can be oncogenic, meaning it has the potential to cause cancer. Certain viruses, such as human papillomavirus (HPV), hepatitis B virus (HBV), and Epstein-Barr virus (EBV), have been linked to the development of various types of cancer. These viruses can infect cells and disrupt their normal functioning, leading to uncontrolled cell growth and tumor formation. Therefore, it is true that a virus can be oncogenic.
8.
What class of viruses cause genital warts, penile cancer and cervical cancer?
Correct Answer
A. Human Papilloma Virus
Explanation
Human Papilloma Virus (HPV) is the correct answer. HPV is a class of viruses that can cause genital warts, as well as certain types of cancer such as penile cancer and cervical cancer. HPV is a sexually transmitted infection and is one of the most common viruses transmitted through sexual contact. It is important to note that while HPV can lead to the development of certain cancers, not all HPV infections will result in cancer. Regular screenings and vaccinations can help prevent and detect HPV-related conditions.
9.
How do new strains of influenza arise?
Correct Answer
D. Both A & C
Explanation
New strains of influenza can arise through both genetic drift and genetic shift. Genetic drift refers to the random changes that occur in the genetic material of the virus over time, leading to the emergence of new strains. On the other hand, genetic shift occurs when two or more different strains of the virus combine their genetic material, resulting in the creation of a new strain with different characteristics. Therefore, it is possible for new strains of influenza to arise through both genetic drift (option A) and genetic shift (option C).
10.
Gram + Streptococcus
Correct Answer
A.
Explanation
Gram + Streptococcus refers to a group of bacteria that are Gram-positive and have a spherical shape. Streptococcus is a genus of bacteria that includes various species, such as Streptococcus pyogenes and Streptococcus pneumoniae. Gram-positive bacteria have a thick peptidoglycan layer in their cell walls, which retains the crystal violet stain during the Gram staining process. This characteristic helps in differentiating them from Gram-negative bacteria. Streptococcus bacteria are known to cause various infections in humans, including strep throat, pneumonia, and skin infections.
11.
Gram + Staphylococcus
Correct Answer
D.
Explanation
Gram-positive Staphylococcus refers to a group of bacteria that are classified as Gram-positive based on their ability to retain the crystal violet stain during the Gram staining process. Staphylococcus is a genus of bacteria that are round in shape and typically form clusters or grape-like structures. Gram-positive Staphylococcus species are commonly found on the skin and mucous membranes of humans and animals. Some species, such as Staphylococcus aureus, can cause various infections in humans, ranging from minor skin infections to more severe conditions like pneumonia and sepsis.
12.
Gram - Bacilli
Correct Answer
C.
Explanation
Bacilli are a type of bacteria that are characterized by their rod-like shape. Gram staining is a common technique used to classify bacteria based on their cell wall composition. Gram-positive bacteria, such as bacilli, retain the crystal violet stain and appear purple under a microscope. This is because their cell walls have a thick layer of peptidoglycan that retains the stain. Gram-negative bacteria, on the other hand, do not retain the stain and appear pink or red. Therefore, the statement "Gram - Bacilli" suggests that the bacilli being referred to are gram-negative bacteria.
13.
Gram negative cell wall is thicker then gram positive cell wall?
Correct Answer
B. False
Explanation
The statement is false because gram-positive cell walls are thicker than gram-negative cell walls. Gram-positive bacteria have a thick layer of peptidoglycan in their cell walls, which gives them a purple color when stained with the Gram stain. In contrast, gram-negative bacteria have a thinner layer of peptidoglycan and an additional outer membrane, making their cell walls thinner overall.
14.
What is Acid-fast bacteria responsible for?
Correct Answer
B. Tuberculosis
Explanation
Acid-fast bacteria are responsible for causing tuberculosis. Tuberculosis is a highly contagious bacterial infection that primarily affects the lungs but can also affect other parts of the body. Acid-fast bacteria, such as Mycobacterium tuberculosis, have a unique cell wall structure that makes them resistant to staining with conventional dyes. This staining property allows for their identification under a microscope, aiding in the diagnosis of tuberculosis.
15.
An antibiotic is?
Correct Answer
C. Product of a microbe that can inhibit or kill other microbes
Explanation
An antibiotic is a product of a microbe that can inhibit or kill other microbes. Antibiotics are substances produced by microorganisms, such as bacteria or fungi, that have the ability to kill or inhibit the growth of other microorganisms. They are commonly used in medicine to treat bacterial infections and are effective in combating various types of bacteria. Antibiotics work by targeting specific components or processes within the microorganism, disrupting their normal functioning and ultimately leading to their death or inhibition of growth.
16.
Bacteriocidial is?
Correct Answer
B. Kills microbes
Explanation
The term "bacteriocidal" refers to something that has the ability to kill microbes. Therefore, the correct answer is "Kills microbes." This term is often used to describe substances or agents that have antimicrobial properties and can effectively eliminate or destroy bacteria and other microorganisms.
17.
Minimal Inhibitory Concentration is?
Correct Answer
A. Minimal concentration of antibiotic that will inhibit the visible growth
Explanation
Minimal Inhibitory Concentration (MIC) refers to the lowest concentration of an antibiotic that is needed to inhibit the visible growth of a particular bacterium. This means that the antibiotic is able to prevent the bacteria from growing and reproducing, but it may not necessarily kill the bacteria. The MIC is an important measure in determining the effectiveness of an antibiotic against a specific bacterium and helps in determining the appropriate dosage for treatment.
18.
Primary antifungals target?
Correct Answer
B. Ergosterol
Explanation
Primary antifungals target ergosterol. Ergosterol is a crucial component of the fungal cell membrane, similar to cholesterol in animal cells. Antifungal drugs specifically target ergosterol to disrupt the integrity and function of the fungal cell membrane, leading to the death or inhibition of fungal growth. By targeting ergosterol, antifungal medications can effectively treat fungal infections while minimizing harm to human cells, which do not contain ergosterol.
19.
What is PCR?
Correct Answer
C. Amplifies a single or a few copies of DNA across several orders of magnitude generating thousands to millions of copies of a particular DNA sequence
Explanation
PCR, or polymerase chain reaction, is a technique used to amplify a small amount of DNA into a larger quantity. It works by repeatedly heating and cooling the DNA sample, allowing specific DNA sequences to be replicated. This amplification process generates thousands to millions of copies of the targeted DNA sequence, making it easier to study and analyze. PCR is widely used in various fields such as research, forensic analysis, and medical diagnostics.