Biology Quiz 2021-2022

Competitive Exams for the Academic Year 2021-2022

Question 1

• Chemoautotrophic organisms can use CO2 as a source of carbon and inorganic chemicals as a source of energy and electrons.
• These organisms can be classified into three types: chemoautotrophic lithotrophic, chemoautotrophic non-lithotrophic, and mixotrophic.
• The correct answer is chemoautotrophic lithotrophic.

Cell Wall Structure

• Teichoic acid is absent in the cell wall structure of Gram-positive bacteria.
• The correct answer is teichoic acid.

Nutrient Requirements

• Some microorganisms are unable to synthesize growth factors.
• The correct answer is oxytrophic non-autotrophic.

Bacterial Motility

• The movement of Proteus bacteria stops at an agar concentration of 5%.

Nitrosomonas

• Nitrosomonas is a chemoautotrophic non-lithotrophic organism.

Question 2

• There are several types of inhibitors that affect enzyme activity, including competitive, non-competitive, uncompetitive, and suicide inhibitors.

Question 3

• Staphylococcus aureus produces coagulase, which is responsible for the formation of abscesses on the skin.
• The correct answer is coagulase.

Blood Culture

• A negative blood culture result may be due to the presence of antibiotics, which can inhibit the growth of bacteria.
• The correct answer is the presence of antibiotics.

The Etiology of Sore Throat

• The etiology of sore throat can be determined by throat culture, ASO titer, or throat antigen detection.

Virulence

• Virulence refers to the ability of bacteria to cause disease in a susceptible host.

Lyme Disease

• The diagnosis of Lyme disease can be confirmed by Borrelia burgdorferi immunoassay, immunoblot, or PCR of CSF.

Spore Formation

• Spore formation involves several stages, including sporulation, germination, and outgrowth.

F-pilus

• F-pilus is essential for chromosome transfer by conjugation.

Gene Expression

• More than one RNA polymerase can transcribe a specific gene at a given time.
• More than one ribosome can translate a specific transcript at a given time.
• Translation begins at a site called a terminator.

Eukaryotic Gene Expression

• Eukaryotic gene expression involves the addition of a 5' cap and a poly A tail to the mRNA.
• Introns must be removed to create the mRNA that is translated.
• Translation begins at the first AUG.

Multiple Choice

• Spliceosomes are present in eukaryotes but not prokaryotes.
• The nitrogen bases in DNA are bonded to the deoxyribose.

Short Answer

• Conjugation involves the transfer of DNA from one bacterium to another through direct cell-to-cell contact.
• Transformation involves the uptake of free DNA by a bacterium.
• Transduction involves the transfer of DNA from one bacterium to another through a bacteriophage.
• Direct tests involve the detection of bacterial antigens or nucleic acids, while indirect tests involve the detection of antibodies or other immune responses.

Additional Questions

• Microbial activity level can be determined by measuring the rate of substrate utilization or the production of metabolic byproducts.
• The carbon cycle in land and microorganisms differs in terms of the sources of carbon and the types of organisms involved.
• There is no significant difference between the water cycle in land and the water cycle on the mainland.

Question 13

• Ciprofloxacin inhibits DNA gyrase.
• Sulfanilamide is a synthetic antimicrobial drug.
• Narrow-spectrum antimicrobial drugs are appropriate for treating specific infections, such as strep throat caused by Streptococcus pyogenes.
• Glycopeptides are a type of β-lactam antimicrobial.
• β-lactamase resistance involves the degradation of β-lactam antibiotics.

Question 14

• The outer membrane of Gram-negative bacteria is a selective target for antibacterial drugs.
• An example of an antimicrobial compound that targets this structure is polymyxin.

A competitive exam for the academic year 2021-2022, covering various biology topics including cellular structures and microbiology.