BIO 251 EXAM 2 NEWEST 2024-2025 ACTUAL EXAM

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BIO 251 EXAM 2 NEWEST 2024-2025 ACTUAL EXAM

COMPLETE 100 QUESTIONS AND CORRECT

DETAILED ANSWERS (VERIFIED ANSWERS )

|ALREADY GRADED A+

Which of the following statements about how the skin prevents disease is false?

• salt in sweat retards microbial growth
• the skin is the most common route for organisms to penetrate the

body

• oil glands on the skin make it waterproof
• native microbes that live on your skin help protect you from infection
• ANSWER- b) the skin is the most common route for organisms to

penetrate the body

This antimicrobial protein is found at high levels in lacrimal secretions (tears)

• lysozyme
• defensins
• sebum

d) C3b - ANSWER- a) lysozyme

Which component of the compliment system would stimulate neutrophils to phagocytize an attached cell? 1 / 4

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a) C5a

b) C5b

c) C3a

d) C3b - ANSWER- d) C3b

Which of the following would prevent a microbe from activating the Alternative pathway of the compliment system?

• a bacteria that has an enzyme that degrades antibodies
• a bacteria that has a thick cell wall
• a bacteria that can prevent C3b from binding to it
• a bacteria that contain no mannose - ANSWER- c) a bacteria that can

prevent C3b from binding to it

Which of the following is NOT a feature of the skin that allows it to serve as a barrier to infection?

• melanin in the skin is toxic to a bacteria
• sweat creates a sling environment that prevents non-halotolerant

bacteria from growing

• tight junctions in keratinocytes make the skin waterproof
• resident flora produce bacteriocins - ANSWER- a) melanin in the skin

is toxic to a bacteria

The immune system cell most commonly associated with allergies is:

• neutrophil
• eosinophil 2 / 4

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• basophil
• macrophage - ANSWER- c) basophil

Which of the following would be an example of a PAMP?

a) GaGs on the surface of eukaryotic of a PAMP

b) C3b bound to bacteria

• peptidoglycan
• tissue factor - ANSWER- c) peptidoglycan

This cytokine is released by virally infected cells, anti-viral - ANSWER- interferon

Suppose that someone's blood stem cells in their marrow ware dividing and developing into B cells. What cytokine might be responsible for this?

• chemokines
• tumor necrosis factor
• colony stimulating factor
• interferon - ANSWER- c) colony stimulating factor

Which of the following cells would likely have Toll-like receptors (TLRs)?

• mast cells
• dendritic cells 3 / 4

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• neutrophils

d) T-lymphocytes

• hepatocytes - ANSWER- mast cells, dendritic cells

Which of the following would be most likely to be detected by a Rig- like receptor (RLR)

• bacterial DNA
• helminth proteins
• double stranded RNA

d) LPS - ANSWER- c) double stranded RNA

What event during inflammation is responsible for swelling?

• diapedesis
• increasing vascular permeability
• vasodilation
• increased sensitivity of nociceptors - ANSWER- b) increasing

vascular permeability

Put the steps of Phagocytosis in order.Chemotaxis Exocytosis Recognition and Attachment Engulfment (endocytosis) Destruction and Digestion

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