Biology

Antibiotics and Immunity

859 Questions

Prepare for your science sections with these questions on antibiotics and immunity. The hub covers various classes of antibiotics, their sources, and mechanisms of microbial resistance. It also addresses the human antiviral response.

Antibiotic classes and sourcesMicrobial resistance mechanismsAntiviral proteinsDisease treatments

Antibiotics and Immunity Questions

Multiple choice botany living world and classification of microbes gram staining microbiology: organisms in industry cell wall and cell membrane

The characteristic of Gram - negative bacteria is  

  1. Presence of porins

  2. >10% lipids in the cell wall

  3. Endotoxins

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Gram - negative bacteria display the following characteristics: outer membrane containing lipopolysaccharide (which consists of lipid A, core polysaccharide, and O antigen) in its outer leaflet and phospholipids in the inner leaflet; porins exist in the outer membrane, which act like pores for particular molecules; lipoproteins are attached to the polysaccharide membrane.

Multiple choice botany living world and classification of microbes gram staining microbiology: organisms in industry cell wall and cell membrane

Wall of Gram +ve bacteria possess

  1. Acetic acid

  2. Teichoic acid

  3. Glutamic acid

  4. Malic acid
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Gram positive cells are characterized by presence of single thick layer of cell wall which is made up of peptidogycan, teichoic acid and lipoteichoic acid. Teichoic acid is acidic polymer of ribitol phosphate /glycerol phosphate and is covalently linked to peptidoglycan layer. Acetic acid is organic compound and is the main component of vinegar. Glutamic acid is one of the 20 standard amino acids and also serves as neurotransmitter. Malic acid is organic compound and serves as important intermediate in number of biochemical pathways; Kreb cycle and Glyoxalate cycle, etc. Thus, the correct answer is option B.

Multiple choice botany bacteria bacteria - friend and foe useful and harmful bacteria bacteria; benefits and harmful effects

Antibiotic are mostly obtained from

  1. Bacteria

  2. Viruses

  3. Fungi

  4. Angiosperms
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The antibiotics are substances produced by the natural metabolic processes of spore forming aerobic bacteria and fungi as their natural defense against other microorganisms. Among bacteria and fungi, bacterial genera outnumber the fungal genera in production of antibiotics. The highest numbers of antibiotics are derived from bacterial genera Streptomyces and Bacillus and fungal genera Penicillium and Cephalosporium. This makes option A correct. Viruses do not perform any metabolic activity outside the host and hence, do not produce any antimicrobial agents. Angiosperms are most developed flowering plants that have number of adaptation to make them less susceptible for competition for food and space; they do not produce antibiotics. Thus, the correct answer is option is A.

Multiple choice botany bacteria bacteria - friend and foe useful and harmful bacteria bacteria; benefits and harmful effects

Antibiotics cure disease by

  1. Competitive inhibition

  2. Fighting with the disease causing organism

  3. Turning the pathogen out of the body

  4. Removing the pain
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Antibiotics serve as metabolic analogs and control the microbial growth by competing with the necessary enzyme to halt the growth of bacterial cells. Antibiotics occupy the enzyme’s active site thereby blocking the binding of its natural substrate to the enzyme. This puts the whole pathway to halt. Inhibition of enzyme activity by a metabolic analog of the natural substrate is termed as competitive inhibition.

Therefore, the correct answer is option A.

Multiple choice botany bacteria bacteria - friend and foe useful and harmful bacteria bacteria; benefits and harmful effects

Antibiotics are mostly produced commercially from

  1. Immune host

  2. Parasitic fungi

  3. Saprophytic bacteria

  4. Viruses
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The antibiotics are substances produced by the natural metabolic processes of spore forming aerobic bacteria and fungi as their natural defence against other microorganisms. Immune host is the one which has acquired immunity against certain antigen by administration of antibiotics. It produces antibodies, not the antibiotics which makes option A incorrect. Commercial production of antibiotics by parasitic fungi needs their culture in live host cells which is a tedious and expensive process; Option B is incorrect. Saprophytic bacteria feed on dead and decaying organic matter and therefore, can easily be cultured on synthetic medium; option C is correct. Since, viruses are metabolically inactive outside the host cell and depend on host for their own nutritional requirements, they do not produce antibodies. Option D is incorrect. Thus, the correct answer is option C. 

Multiple choice botany bacteria bacteria - friend and foe useful and harmful bacteria bacteria; benefits and harmful effects

Harmful substances secreted by bacteria are known as 

  1. Antibiotics

  2. Toxins

  3. Antibodies

  4. Paratopes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Toxin is the harmful substance secreted by bacteria. It affects the immune system of the host. It causes infection and disease in the host by damaging the tissues. Paratope is an antigen-binding site present on the antibody. 

Thus, the correct answer is option B.

Multiple choice botany bacteria bacteria - friend and foe useful and harmful bacteria bacteria; benefits and harmful effects

Broad spectrum antibiotic, chloramphenicol is produced by

  1. Streptomyces venezuelae

  2. Streptomyces griseus

  3. Streptomyces aureofaciens

  4. Bacillus subtilis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Chloramphenicol/chloromycetin is an antibiotic that is used in the treatment of a many bacterial infections like conjunctivitis, meningitis, cholera, typhoid fever. It is a broad spectrum antibiotic. It is produced by bacteria Streptomyces venezuelae. 
Thus, the correct answer is 'Streptomyces venezuelae.'
Multiple choice botany bacteria bacteria - friend and foe useful and harmful bacteria bacteria; benefits and harmful effects

Application of penicillin on bacterial cell inhibits the synthesis of 

  1. DNA

  2. RNA

  3. Cell wall

  4. Protein
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The antibiotics are the chemical substances produced by the natural metabolic processes of bacteria and fungi as their natural defense against other microorganisms. Penicillin is an antibiotic that target the peptide cross-links in the peptidoglycan and disrupt the cell wall integrity. Exposure of penicillin to bacteria stops the cell wall synthesis by inhibition of formation of peptide linkage and bacteria become protoplast (a fragile cell bounded only by a membrane) which is highly susceptible to lysis.  Thus, the correct answer is option C.

Multiple choice chemistry chemistry in daily life antimicrobials and antifertility drugs therapeutic action of different classes of drugs drugs and their classification

Which of the following antibiotics is bactericidal?

  1. Erythromycin

  2. Tetracycline

  3. Penicillin

  4. Chloramphenicol
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • An antibiotic refers to a substance produced wholly or partly by chemical synthesis, which in low concentrations inhibits the growth or destroys microorganisms by intervening in their metabolic processes.
  • Antibiotics have either cidal (killing) effect or a static (inhibitory) effect on microbes.
  • Bactericidal-Penicillin,Aminoglycosides,Ofloxacin
  • Bacteriostatic-Erythromycin,Tetracycline,Chloramphenicol
  • Ampicillin and Amoxycillin are synthetic modifications of penicillins. These have broad spectrum. It is absolutely essential to test the patients for sensitivity (allergy) to penicillin before it is administered
Multiple choice chemistry chemistry in daily life antimicrobials and antifertility drugs therapeutic action of different classes of drugs drugs and their classification

Antiseptic are the chemical which either ___orthe growth of microorganisms and are applied to the ___.

  1. kill, prevent, living tissues

  2. kill, prevent, non-living objects

  3. increase, decrease, living tissues

  4. kill, increase, non-living tissues
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Antiseptics are applied to the living tissues such as wounds, cuts, ulcers and diseased skin surfaces.
  • Antiseptics helps to kill or prevent the growth of microorganisms.
  • Examples are furacine, soframicine, etc. 
  • Commonly used antiseptic, dettol is a mixture of chloroxylenol and terpineol. Bithionol (the compound is also called bithional) is added to soaps to impart antiseptic properties. Iodine is a powerful antiseptic. 
  • Its 2-3 per cent solution in alcoholwater mixture is known as tincture of iodine. It is applied on wounds. 
  • Iodoform is also used as an antiseptic for wounds. 
  • Boric acid in dilute aqueous solution is weak antiseptic for eyes.
Multiple choice chemistry chemistry in daily life antimicrobials and antifertility drugs therapeutic action of different classes of drugs drugs and their classification

Which of the following statements is not correct about penicillin?

  1. Penicillin G has a narrow spectrum.

  2. It is extracted from antibacterial fungus Penicillium.

  3. Ampicillin and amoxycillin are synthetic modifications of penicillins.

  4. It has bacteriostatic effect.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • The real revolution in antibacterial therapy began with the discovery of Alexander Fleming in 1929, of the antibacterial properties of a Penicillium fungus. It is extracted from antibacterial fungus Penicillium.
  • Penicillin G has a narrow spectrum. Ampicillin and Amoxycillin are synthetic modifications of penicillins. These have broad spectrum. It is absolutely essential to test the patients for sensitivity (allergy) to penicillin before it is administered.
  • Antibiotics have either cidal (killing) effect or a static (inhibitory) effect on microbes. Penicillin has Bactericidal effect.
Multiple choice chemistry chemistry in daily life antimicrobials and antifertility drugs therapeutic action of different classes of drugs drugs and their classification

Which of the following statements is not correct?

  1. Some antiseptics can be added to soaps.

  2. Dilute solutions of some disinfectants can be used as antiseptic.

  3. Disinfectants are antimicrobial drugs.

  4. Antiseptic medicines can be ingested.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Antiseptics are applied to the living tissues such as wounds, cuts, ulcers and diseased skin surfaces. These are not ingested like antibiotics.
  • Bithionol (also called bithional) is added to soaps to impart antiseptic properties.
  • Disinfectants are antimicrobial drugs which are applied to inanimate objects such as floors, drainage system, instruments, etc.
  • Same substances can act as an antiseptic as well as a disinfectant by varying the concentration. For example, 0.2 per cent solution of phenol is an antiseptic while its one per cent solution is disinfectant.
  • Hence, option D is the wrong option.
    Multiple choice chemistry chemistry in daily life antimicrobials and antifertility drugs therapeutic action of different classes of drugs drugs and their classification

    Which of the following is an example of a broad spectrum antibiotic?

    1. Penicillin G

    2. Chloramphenicol

    3. Streptomycin

    4. Ampicillin
    Reveal answer Fill a bubble to check yourself
    B,C,D Correct answer
    Explanation

    Since, Chloramphenicol functions by inhibiting bacterial protein synthesis, the drug chloramphenicol has a very broad spectrum of activity. It is active against gram-positive bacteria (including most strains of MRSA), gram-negative bacteria and anaerobes.

    Multiple choice chemistry chemistry in daily life antimicrobials and antifertility drugs therapeutic action of different classes of drugs drugs and their classification

    Which of the following are synthetic antimicrobial chemicals, consumed by humans?

    1. Insulin

    2. Sulphadiazine

    3. Hydrochloric acid

    4. Penicillin
    Reveal answer Fill a bubble to check yourself
    B,D Correct answer
    Explanation

    Sulphadiazine and penicillin are the synthetic antimicrobial chemicals consumed by humans. Insulin and hydrochloric acid are produced by the body.

    Multiple choice chemistry chemistry in daily life antimicrobials and antifertility drugs therapeutic action of different classes of drugs drugs and their classification

    The first anti-microbial to be discovered is:

    1. Soframicin

    2. Pencillin

    3. Oflaxacin

    4. Terpineol
    Reveal answer Fill a bubble to check yourself
    B Correct answer
    Explanation

    An antimicrobial tends to destroy/prevent development of microbes such as bacteria, fungi, virus, or other parasites selectively, and inhibit their pathogenic actions. 
    Alexander Fleming was the first to discover a natural antimicrobial fungus known as Penicillium rubens. The substance he extracted from the fungus was named Penicillin.