Nokea
How many Toll-like receptors (TLRs) are found in humans?
- A. 5
- B. 8
- C. 10
- D. 12
Correct Answer: C
Rationale: The correct answer is C: 10. Toll-like receptors (TLRs) are a family of proteins involved in the innate immune response. In humans, there are 10 known TLRs that recognize different pathogen-associated molecular patterns. Each TLR is specific to different types of pathogens, allowing for a diverse recognition and response system. Therefore, the correct answer is 10. Choices A, B, and D are incorrect because they do not match the known number of TLRs in humans, which is 10.
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the characteristic of blood types AB is
- A. a general receptor
- B. a general donor
- C. a receptor and donor
- D. neither donating nor receptor
Correct Answer: A
Rationale: The correct answer is A: a general receptor. Blood type AB individuals have both A and B antigens on their red blood cells, making them universal recipients since they can receive blood from all blood types without rejection. This is because they have no antibodies against A or B antigens. The other choices are incorrect because blood type AB individuals cannot be universal donors (choice B) as they have both A and B antigens, not making them suitable for all recipients. They are not both a receptor and donor (choice C) as they can only receive blood from all types, not donate to all. Lastly, they are not neither donating nor a receptor (choice D) since they can receive blood from all types, making them a receptor.
Which of the following are not found in Cyanobacteria?
- A. thylakoids
- B. gas vesicles
- C. chloroplasts
- D. heterocysts
Correct Answer: C
Rationale: The correct answer is C: chloroplasts. Cyanobacteria do not have chloroplasts because they are prokaryotic organisms and do not possess membrane-bound organelles like chloroplasts found in eukaryotic cells. Instead, they perform photosynthesis using thylakoids, which are membrane-bound compartments where photosynthesis occurs. Gas vesicles are also present in cyanobacteria and help regulate their buoyancy. Heterocysts are specialized cells that aid in nitrogen fixation, a process that allows cyanobacteria to convert atmospheric nitrogen into a form that can be used by the organism. Therefore, the absence of chloroplasts in cyanobacteria makes choice C the correct answer.
What is the role of angiogenesis in cancer progression?
- A. Promotes tumor shrinkage
- B. Prevents metastasis
- C. Supports tumor growth by forming new blood vessels
- D. Reduces oxygen supply to the tumor
Correct Answer: C
Rationale: Angiogenesis supports tumor growth by forming new blood vessels to supply nutrients and oxygen.
The PAMP recognized by NOD1 is
- A. Flagellin
- B. CpG DNA
- C. Peptidoglycan
- D. K+ efflux
Correct Answer: C
Rationale: The correct answer is C: Peptidoglycan. NOD1 recognizes peptidoglycan, a component of bacterial cell walls. This recognition triggers an immune response. Flagellin (A) is recognized by TLR5, CpG DNA (B) is recognized by TLR9, and K+ efflux (D) is not a PAMP recognized by NOD1. Thus, only peptidoglycan is the correct choice for NOD1 recognition.
In order to grow, all microorganisms require:
- A. liquid water
- B. organic substances
- C. oxygen
- D. warm temperatures
Correct Answer: A
Rationale: The correct answer is A: liquid water. Water is essential for all cellular functions, including metabolism and nutrient transport. Without water, microorganisms cannot grow or survive. Organic substances (choice B) are important as a nutrient source, but water is indispensable for growth. While oxygen (choice C) and warm temperatures (choice D) can enhance growth for some microorganisms, they are not universally required for all microorganisms to grow.