Which of the following is an active transport mechanism?
- A. pinocytosis
- B. facilitated diffusion
- C. filtration
- D. pinocytosis
Correct Answer: D
Rationale: The correct answer is D: pinocytosis. This is an active transport mechanism where cells engulf fluids or solutes through vesicles. Energy is required to transport substances against a concentration gradient. A is incorrect as pinocytosis is an active process, not passive like pinocytosis. B is incorrect as facilitated diffusion is a passive process that uses carrier proteins to move substances down a concentration gradient. C is incorrect as filtration is a passive process that relies on pressure gradients to move substances across a barrier. Therefore, D is the correct choice as it involves the active transport of substances into the cell.
You may also like to solve these questions
Viruses can infect
- A. plants.
- B. bacteria.
- C. animals.
- D. all organisms.
Correct Answer: D
Rationale: The correct answer is D because viruses have the ability to infect all organisms, including plants, bacteria, animals, and even fungi. Viruses are non-living entities that require a host cell to replicate and spread. They can infect a wide range of organisms by attaching to specific receptors on the host cell's surface. Therefore, the correct answer is D as viruses have the capability to infect all living organisms. Choices A, B, and C are incorrect because viruses can infect not only plants, bacteria, and animals but also other organisms, making choice D the most comprehensive and accurate option.
Which bacteria is responsible for causing pneumonia?
- A. Streptococcus pneumoniae
- B. Mycobacterium tuberculosis
- C. Escherichia coli
- D. All of the above
Correct Answer: D
Rationale: The correct answer is D: All of the above. Streptococcus pneumoniae, Mycobacterium tuberculosis, and Escherichia coli can all cause pneumonia, but through different mechanisms. S. pneumoniae is a common cause of community-acquired pneumonia, M. tuberculosis can lead to tuberculosis-related pneumonia, and E. coli can cause pneumonia in immunocompromised individuals. Therefore, all three bacteria can be responsible for causing pneumonia, making option D the correct choice. Option A, Streptococcus pneumoniae, is correct but does not cover all possible causes of pneumonia. Option B, Mycobacterium tuberculosis, is too specific and does not include other common causes. Option C, Escherichia coli, is also a possible cause of pneumonia but does not account for all potential pathogens.
Which one belongs to genus Orthopoxvirus?
- A. Vaccinia virus
- B. Smallpox virus
- C. Cowpox virus
- D. All of these
Correct Answer: D
Rationale: The correct answer is D because all three viruses, Vaccinia virus, Smallpox virus, and Cowpox virus, belong to the genus Orthopoxvirus. They share similar characteristics and genetic makeup. Vaccinia virus is used as a vaccine against smallpox, Smallpox virus causes smallpox disease, and Cowpox virus can infect both animals and humans. Choice A, B, and C are incorrect because each of these viruses is a member of the Orthopoxvirus genus.
Which of the following is a type of acute infection generally caused by group A Streptococcus?
- A. Carbuncle
- B. Impetigo
- C. Erysipelas
- D. Acne
Correct Answer: C
Rationale: The correct answer is C: Erysipelas. Erysipelas is a type of acute infection caused by group A Streptococcus bacteria. This bacteria infects the upper dermis and superficial lymphatics, leading to a distinct raised, well-demarcated, erythematous skin lesion. The other choices are incorrect because: A Carbuncle is a deep skin infection involving hair follicles, B Impetigo is a superficial skin infection caused by Staphylococcus or Streptococcus bacteria, and D Acne is a chronic inflammatory skin condition not typically caused by group A Streptococcus.
Bacterioscopic examination of chancre material revealed some mobile, long, convoluted microorganisms with 8-12 regular coils. These features are typical for:
- A. Treponema
- B. Borrellia
- C. Leptospira
- D. Vibrios
Correct Answer: A
Rationale: The correct answer is A: Treponema. Treponema pallidum is a spirochete bacterium that appears as long, thin, and spiral-shaped microorganisms with 8-12 regular coils under the microscope. This characteristic morphology is specific to Treponema species, making it the correct choice. Borrelia, Leptospira, and Vibrios have different shapes and arrangements under the microscope, making them incorrect choices in this scenario.