BIO 152 Chpt 25 Health And Diseases (Ii)

Question 1

1. Which of the following is NOT a characteristic of viruses? a) They are intracellular pathogenic particles b) They can cause diseases like rabies smallpox and influenza c) They can replicate independently outside of a host cell d) The first virus described was the tobacco mosaic virus (TMV)

Answer 1

Answer: c) They can replicate independently outside of a host cell Explanation: Viruses are obligate intracellular parasites meaning they require a host cell to replicate

Question 2

2. Bacterial capsules primarily contribute to: a) Motility and adhesion to host cells b) Evasion of host immune responses and antibiotic resistance c) Nutrient uptake and metabolism d) Toxin production and release

Answer 2

Answer: b) Evasion of host immune responses and antibiotic resistance Explanation: Capsules are composed of polysaccharides that help bacteria avoid phagocytosis by the host’s immune cells and can also hinder the effectiveness of antibiotics

Question 3

3. The cell wall of bacteria plays a crucial role in: a) Protein synthesis and energy production b) Determining Gram staining characteristics and susceptibility to certain antibiotics c) Genetic material storage and replication d) Capsule formation and nutrient transport

Answer 3

Answer: b) Determining Gram staining characteristics and susceptibility to certain antibioticsExplanation: The structure of the bacterial cell wall differentiates Gram-positive and Gram-negative bacteria influencing their response to different types of antibiotics

Question 4

4. Septic shock a life-threatening condition is primarily triggered by: a) Excessive antibody production b) Release of lipopolysaccharide (LPS) from Gram-negative bacteria c) Viral infection and cell lysis d) Fungal toxin accumulation in the bloodstream

Answer 4

Answer: b) Release of lipopolysaccharide (LPS) from Gram-negative bacteria Explanation: LPS a component of the outer membrane of Gram-negative bacteria acts as a potent endotoxin triggering an overwhelming immune response leading to septic shock

Question 5

5. Exotoxins produced by certain bacteria are primarily characterized as: a) Structural components of the bacterial cell wall b) Enzymes that are secreted and directly damage host cells c) Molecules that trigger an excessive immune response d) Surface proteins responsible for bacterial adhesion

Answer 5

Answer: b) Enzymes that are secreted and directly damage host cellsExplanation: Exotoxins are proteins released by bacteria that can have various harmful effects on host cells often acting as enzymes to disrupt cellular processes

Question 6

6. The primary mechanism by which pathogens adhere to host surfaces is through: a) Capsule formation b) Adhesins specialized surface proteins c) Toxin release d) Flagellar movement

Answer 6

Answer: b) Adhesins specialized surface proteins Explanation: Adhesins enable pathogens to attach to specific receptors on host cells facilitating colonization and subsequent infection

Question 7

7. Fimbriae a type of bacterial adhesin are best described as: a) Long whip-like structures used for motility b) Short hair-like appendages that mediate strong attachment to host cells c) Enzymes that break down host tissues d) Toxins that disrupt host cell function

Answer 7

Answer: b) Short hair-like appendages that mediate strong attachment to host cells Explanation: Fimbriae allow for tight binding to host cells contributing to the establishment of infection

Question 8

8. Which of the following is NOT a characteristic of fungal pathogens? a) They are eukaryotic microorganisms b) They possess a cell wall containing chitin c) They are obligate intracellular parasites d) Some species can cause significant diseases in humans

Answer 8

Answer: c) They are obligate intracellular parasites Explanation: Unlike viruses fungi are not obligate intracellular parasites and can grow and reproduce outside of host cells

Question 9

9. The fungal capsule contributes to pathogenicity by: a) Inhibiting antibiotic activity b) Enhancing nutrient uptake tissue invasion and dissemination within the host c) Triggering an excessive inflammatory response d) Facilitating adhesion to host cells via specific receptors

Answer 9

Answer: b) Enhancing nutrient uptake tissue invasion and dissemination within the host Explanation: The capsule provides protection and supports the fungus’s ability to spread and invade tissues

Question 10

10. The immune system recognizes foreign invaders through: a) Antigens specific molecules on the surface of pathogens b) Random interactions with host cells c) Physical barriers like skin and mucous membranes d) Non-specific inflammatory responses

Answer 10

Answer: a) Antigens specific molecules on the surface of pathogens Explanation: Antigens act as identifiers triggering the immune system to mount a targeted response against the invading pathogen

Question 11

11. Antibodies key components of the adaptive immune response are produced by: a) T cells b) Macrophages c) B cells d) Neutrophils

Answer 11

Answer: c) B cells Explanation: B cells differentiate into plasma cells that secrete antibodies specific to the encountered antigen

Question 12

12. The primary and secondary immune responses differ in their: a) Speed and intensity b) Specificity towards the antigen c) Type of immune cells involved d) Dependence on T cell activation

Answer 12

Answer: a) Speed and intensity Explanation: The secondary immune response is faster and more robust due to the presence of memory cells generated during the primary response

Question 13

13. Passive immunity acquired through the transfer of preformed antibodies is characterized by: a) Long-lasting protection b) Immediate but temporary protection c) Activation of the recipient’s immune system d) Development of memory cells

Answer 13

Answer: b) Immediate but temporary protection Explanation: Passive immunity provides instant defense but fades as the transferred antibodies are cleared from the recipient’s body

Question 14

14. Agglutination reactions used in diagnostic tests involve: a) Clumping of antigens in the presence of specific antibodies b) Formation of a visible precipitate in a solution c) Binding of fluorescent dyes to target antigens d) Activation of complement proteins leading to cell lysis

Answer 14

Answer: a) Clumping of antigens in the presence of specific antibodies Explanation: Agglutination tests detect the presence of specific antibodies based on their ability to cross-link antigens forming visible aggregates

Question 15

15. Immunofluorescence techniques rely on the use of: a) Radioactive isotopes to label antibodies b) Enzymes that produce a color change upon antigen binding c) Antibodies tagged with fluorescent dyes d) Complement proteins to visualize antigen-antibody complexes

Answer 15

Answer: c) Antibodies tagged with fluorescent dyesExplanation: Immunofluorescence allows for the visualization of specific antigens within cells or tissues using fluorescently labeled antibodies

Question 16

16. Vaccines provide active immunity by: a) Transferring preformed antibodies to the recipient b) Exposing the immune system to weakened or inactive forms of pathogens c) Directly killing or inhibiting the growth of pathogens d) Suppressing the immune response to prevent harmful reactions

Answer 16

Answer: b) Exposing the immune system to weakened or inactive forms of pathogens Explanation: Vaccines stimulate the production of memory cells without causing disease providing long-term protection against specific pathogens

Question 17

17. Antibiotics primarily target: a) Human cells to enhance immune responses b) Bacterial cells inhibiting their growth or killing them c) Viral particles to prevent replication d) Fungal spores to prevent germination

Answer 17

Answer: b) Bacterial cells inhibiting their growth or killing themExplanation: Antibiotics are designed to exploit differences between bacterial and human cells to selectively inhibit or eliminate bacterial infections

Question 18

18. Biopesticides offer a more environmentally friendly approach to pest control compared to chemical pesticides because they: a) Are broad-spectrum targeting a wide range of pests b) Are derived from natural sources and often target specific pests c) Persist in the environment for long periods providing extended protection d) Have no impact on non-target organisms

Answer 18

Answer: b) Are derived from natural sources and often target specific pests Explanation: Biopesticides reduce the risks associated with chemical residues and minimize harm to beneficial insects and other organisms

Question 19

19. Biofertilizers contribute to plant growth by: a) Directly providing essential nutrients through chemical formulations b) Enhancing the availability of nutrients like nitrogen and phosphorus through microbial activity c) Suppressing the growth of harmful bacteria and fungi in the soil d) Modifying soil pH to optimize nutrient uptake

Answer 19

Answer: b) Enhancing the availability of nutrients like nitrogen and phosphorus through microbial activity Explanation: Biofertilizers utilize microorganisms to convert nutrients into forms that plants can readily absorb promoting plant growth and health

Question 20

20. Nitrogen-fixing bacteria play a crucial role in the nitrogen cycle by: a) Converting atmospheric nitrogen into nitrates b) Converting atmospheric nitrogen into ammonia c) Breaking down organic matter to release nitrogen d) Absorbing nitrogen from the soil and making it available to plants

Answer 20

Answer: b) Converting atmospheric nitrogen into ammonia Explanation: Nitrogen-fixing bacteria have the unique ability to convert atmospheric nitrogen gas into ammonia a form that plants can utilize

Question 21

21. Mycorrhizae a symbiotic association between fungi and plant roots benefits plants by: a) Providing fixed nitrogen from the atmosphere b) Enhancing nutrient uptake particularly phosphorus c) Protecting roots from pathogenic bacteria and fungi d) Producing growth hormones that stimulate root development

Answer 21

Answer: b) Enhancing nutrient uptake particularly phosphorusExplanation: Mycorrhizal fungi extend the reach of plant roots increasing their access to nutrients especially phosphorus in the soil

Question 22

22. Plant growth-promoting rhizobacteria (PGPR) enhance plant growth through various mechanisms including: a) Production of phytohormones nutrient solubilization and suppression of plant pathogens b) Direct fixation of atmospheric nitrogen into nitrates c) Formation of a physical barrier around roots to prevent pathogen entry d) Decomposition of organic matter to release nutrients

Answer 22

Answer: a) Production of phytohormones nutrient solubilization and suppression of plant pathogensExplanation: PGPR enhance plant growth directly by providing growth-promoting substances and indirectly by improving nutrient acquisiti

Question 23

23. In modern medicine bacteria have found applications in a) Drug delivery systems and cancer treatment b) Production of vaccines against viral diseases c) Gene editing and genetic modification of human cells d) Development of diagnostic tools for early disease detection

Answer 23

Answer: a) Drug delivery systems and cancer treatmentExplanation: Certain bacteria are being explored for their ability to deliver drugs specifically to tumor cells offering potential for targeted cancer therapies

Question 24

24. Clostridium perfringens a bacterium known to cause food poisoning has shown potential in cancer treatment due to its a) Ability to produce potent antibiotics b) Selective targeting of tumor cells in a hypoxic environment c) Stimulation of the immune system to attack cancer cells d) Inhibition of angiogenesis the formation of new blood vessels

Answer 24

Answer: b) Selective targeting of tumor cells in a hypoxic environmentExplanation: Clostridium perfringens thrives in oxygen-deprived environments which are characteristic of many solid tumors making it a potential candidate for targeted cancer therapies

Question 25

25. While bacteria are widely used for various medical and biotechnological applications fungi have shown promise primarily in the production of a) Antibiotics and antiviral drugs b) Anticancer compounds and immunomodulatory agents c) Hormones and enzymes for industrial processes d) Vaccines against bacterial and viral infections

Answer 25

Answer: b) Anticancer compounds and immunomodulatory agents Explanation: Fungi produce a range of bioactive compounds some of which exhibit anticancer and immune-modulating properties

Question 26

26. Trametes versicolor a common mushroom is known to produce polysaccharide-K a compound that a) Exhibits antitumor and immunomodulatory properties b) Acts as a broad-spectrum antibiotic c) Inhibits viral replication d) Promotes wound healing and tissue regeneration

Answer 26

Answer: a) Exhibits antitumor and immunomodulatory properties Explanation: Polysaccharide-K from Trametes versicolor has been studied for its ability to enhance immune responses and inhibit tumor growth

Question 27

27. Boletus edulis another mushroom species has shown potential in the fight against HIV due to its ability to a) Directly kill the virus b) Inhibit the reverse transcriptase enzyme c) Block the binding of the virus to host cells d) Enhance the immune system’s ability to clear the virus

Answer 27

Answer: b) Inhibit the reverse transcriptase enzymeExplanation: Boletus edulis contains a lectin that interferes with the reverse transcriptase enzyme which is crucial for HIV replication

Question 28

28. What type of molecule are exotoxins primarily composed of a) Carbohydrates b) Lipids c) Proteins d) Nucleic Acids

Answer 28

Answer: c) Proteins Explanation: The passage explicitly describes exotoxins as being primarily protein-based

Question 29

29. The ability of a pathogen to invade and spread within a host is referred to as a) Adherence b) Colonization c) Invasion d) Dissemination

Answer 29

Answer: c) Invasion Explanation: The passage uses the term “invasion” to describe the process of pathogens gaining deeper access into host tissues and spreading

Question 30

30. What is the term used to describe the symbiotic association between fungi and plant roots a) Nitrogen fixation b) Mycorrhizae c) Rhizobia d) Biofilm

Answer 30

Answer: b) Mycorrhizae Explanation: The passage clearly defines “Mycorrhizae” as the specific term for the symbiotic relationship between fungi and plant roots

Question 31

31. Which of the following is NOT a function of bacterial capsules a) Protection from the host’s immune system b) Resistance to antibiotics c) Production of toxins d) Adherence to surfaces

Answer 31

Answer: c) Production of toxins Explanation: While capsules contribute to virulence the production of toxins is a separate mechanism and not a direct function of the capsule itself

Question 32

32. What is the name of the component in the outer membrane of Gram-negative bacteria that can trigger septic shock a) Peptidoglycan b) Teichoic acid c) Lipopolysaccharide (LPS) d) Mycolic acid

Answer 32

Answer: c) Lipopolysaccharide (LPS) Explanation: The passage specifically identifies LPS as the molecule responsible for triggering septic shock due to its potent endotoxin activity

Question 33

33. What type of immunity is conferred by the transfer of antibodies from mother to baby through breast milk a) Active immunity b) Passive immunity c) Innate immunity d) Acquired immunity

Answer 33

Answer: b) Passive immunity Explanation: The transfer of pre-formed antibodies such as through breast milk provides immediate but temporary protection known as passive immunity

Question 34

34. Which of the following diagnostic techniques uses enzymes to detect the presence of an antigen a) Agglutination b) Immunofluorescence c) ELISA (Enzyme-Linked Immunosorbent Assay) d) Complement fixation

Answer 34

Answer: c) ELISA (Enzyme-Linked Immunosorbent Assay) Explanation: ELISA is a widely used technique that employs enzyme-labeled antibodies to detect and quantify specific antigens

Question 35

35. Which of the following is an example of a fungal disease that can affect humans a) Influenza b) Tuberculosis c) Tetanus d) Candidiasis

Answer 35

Answer: d) Candidiasis Explanation: The passage lists Candidiasis as one of the examples of significant human diseases caused by fungal pathogens

Question 36

36. What is the primary function of plant growth-promoting rhizobacteria (PGPR) a) Nitrogen fixation b) Enhancement of plant growth c) Disease suppression d) Nutrient cycling

Answer 36

Answer: b) Enhancement of plant growth Explanation: While PGPR may have other roles their primary function is to improve plant growth through various mechanisms

Question 37

37. Which type of bacteria are known to produce afimbrial adhesins a) Gram-positive bacteria only b) Gram-negative bacteria only c) Both Gram-positive and Gram-negative bacteria d) Neither Gram-positive nor Gram-negative bacteria

Answer 37

Answer: c) Both Gram-positive and Gram-negative bacteria Explanation: The passage indicates that both Gram-positive and Gram-negative bacteria can possess afimbrial adhesins

Question 38

38. What is the role of reverse transcriptase in HIV infection a) Integration of viral DNA into the host genome b) Conversion of viral RNA into DNA c) Binding of the virus to host cells d) Assembly of new viral particles

Answer 38

Answer: b) Conversion of viral RNA into DNA Explanation: HIV is a retrovirus and reverse transcriptase is essential for converting its RNA genome into DNA allowing integration into the host’s DNA

Question 39

39. What is the main structural component of fungal cell walls a) Cellulose b) Peptidoglycan c) Chitin d) Keratin

Answer 39

Answer: c) Chitin Explanation: Chitin is a complex polysaccharide that provides structural support to fungal cell walls

Question 40

42 What is the primary function of plant growth-promoting rhizobacteria (PGPR)? a) Nitrogen fixation b) Enhancement of plant growth c) Disease suppression d) Nutrient cycling

Answer 40

Answer: b) Enhancement of plant growthExplanation: While PGPR may have other roles their primary function is to improve plant growth through various mechanisms.

Question 41

45 Which type of bacteria are known to produce afimbrial adhesins? a) Gram-positive bacteria only b) Gram-negative bacteria only c) Both Gram-positive and Gram-negative bacteria d) Neither Gram-positive nor Gram-negative bacteria

Answer 41

Explanation:The passage indicates that both Gram-positive and Gram-negative bacteria can possess afimbrial adhesins.

Question 42

48 What is the role of reverse transcriptase in HIV infection? a) Integration of viral DNA into the host genome b) Conversion of viral RNA into DNA c) Binding of the virus to host cells d) Assembly of new viral particles

Answer 42

Answer: b) Conversion of viral RNA into DNA Explanation: HIV is a retrovirus and reverse transcriptase is essential for converting its RNA genome into DNA allowing integration into the host’s DNA

Question 43

51 What is the main structural component of fungal cell walls? a) Cellulose b) Peptidoglycan c) Chitin d) Keratin

Answer 43

Answer: c) Chitin Explanation: Chitin is a complex polysaccharide that provides structural support to fungal cell walls.

Question 44

52 How do biopesticides differ from chemical pesticides in their mode of action? a) Biopesticides are broad-spectrum while chemical pesticides are target-specific. b) Biopesticides often target specific pests while chemical pesticides may have broader impacts. c) Biopesticides are synthetically produced while chemical pesticides are derived from natural sources. d) Biopesticides persist longer in the environment than chemical pesticides.

Answer 44

Answer: b) Biopesticides often target specific pests while chemical pesticides may have broader impacts. Explanation: One of the key advantages of biopesticides is their often narrower target range minimizing harm to non-target organisms compared to many chemical pesticides

Question 45

5. What is the term for the extracellular pathogenic particles that infect other living organisms?

Answer 45

Answer: VirusesExplanation: Viruses are non-cellular pathogenic particles that require a host to replicate. They infect living organisms by injecting their genetic material into host cells.

Question 46

6. Name one type of bacterial adhesin that facilitates strong attachment to host cells.

Answer 46

Answer: Fimbriae Explanation: Fimbriae are hair-like structures on the surface of bacteria that help them adhere to host cells enabling colonization and infection.

Question 47

7. What is the general term for molecules that can trigger an immune response

Answer 47

Answer: Antigens Explanation: Antigens are substances often proteins or polysaccharides that are recognized by the immune system and trigger the production of antibodies or other immune responses.

Question 48

8. What is the name of the biological preparation that provides active immunity against a particular disease

Answer 48

Answer: Vaccine Explanation: Vaccines stimulate the immune system to recognize and combat specific pathogens by introducing antigens derived from those pathogens.

Question 49

9. Name one example of a genus of bacteria that can be used in biofertilizers for phosphate solubilization.

Answer 49

Answer: PseudomonasExplanation: Pseudomonas species are known to solubilize phosphate making it available for plant uptake thereby enhancing soil fertility and promoting plant growth.