BIO 251 EXAM 1,2 AND 3 BUNDLE NEWEST ACTUAL EXAM COMPLETE QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+
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BIO 251 EXAM 1 NEWEST 2024-2025 ACTUAL EXAM
COMPLETE 100 QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS)
|ALREADY GRADED A+
What is active transport? – ANSWER- the movement of ions or
molecules across a cell membrane into a region of higher
concentration, assisted by enzymes and requiring energy.
What is passive transport? – ANSWER- movement from high to
low, no energy required
What is simple diffusion? – ANSWER- passive transport directly
through the lipid bilayer
What is facilitated diffusion? – ANSWER- passive transport
through carrier protiens
what is an ion channel? – ANSWER- transmembrane protein
that allows diffusion of specific ions across the membrane
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Ion channels can exist in two configurations – ANSWER- open
and closed state
what is a leak channel? – ANSWER- constantly open allowing
passage of ions
what is a gated channel? – ANSWER- closed until stimulated to
open
What is a ligand-gated ion channel? – ANSWER- closed until a
specific chemical binds to open channel
What is a voltage gated channel? – ANSWER- closed until
membrane potential reaches certain voltage
what is mechanical gated channel? – ANSWER- mechanical
force causes gate to open
What is affinity? – ANSWER- binding strength
What is a symporter? – ANSWER- move molecules in the same
direction
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what is an anti porter? – ANSWER- moves molecules in oposite
directions
what is a gap junction? – ANSWER- channels formed between
two cells via connexons
What is a chemical messenger? – ANSWER- any compound that
serves to transmit a message
What is an autocrine? – ANSWER- when released binds to
receptor on the same cell that released it
What is paracrine? – ANSWER- acts on the neighboring cell
what is endocrine? – ANSWER- Involves the release of a
chemical signal into the blood
What are neurotransmitters? – ANSWER- messenger of the
nervous system
What are cytokines? – ANSWER- can be transported in the
blood, most act on neighboring cells, released by most cell types
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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?
a) salt in sweat retards microbial growth
b) the skin is the most common route for organisms to penetrate the
body
c) oil glands on the skin make it waterproof
d) 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)
a) lysozyme
b) defensins
c) sebum
d) C3b – ANSWER- a) lysozyme
Which component of the compliment system would stimulate
neutrophils to phagocytize an attached cell?
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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) a bacteria that has an enzyme that degrades antibodies
b) a bacteria that has a thick cell wall
c) a bacteria that can prevent C3b from binding to it
d) 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?
a) melanin in the skin is toxic to a bacteria
b) sweat creates a sling environment that prevents non-halotolerant
bacteria from growing
c) tight junctions in keratinocytes make the skin waterproof
d) 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:
a) neutrophil
b) eosinophil
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c) basophil
d) 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
c) peptidoglycan
d) tissue factor – ANSWER- c) peptidoglycan
This cytokine is released by virally infected cells, anti-viral – ANSWERinterferon
Suppose that someone’s blood stem cells in their marrow ware dividing
and developing into B cells. What cytokine might be responsible for
this?
a) chemokines
b) tumor necrosis factor
c) colony stimulating factor
d) interferon – ANSWER- c) colony stimulating factor
Which of the following cells would likely have Toll-like receptors
(TLRs)?
a) mast cells
b) dendritic cells
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c) neutrophils
d) T-lymphocytes
e) hepatocytes – ANSWER- mast cells, dendritic cells
Which of the following would be most likely to be detected by a Riglike receptor (RLR)
a) bacterial DNA
b) helminth proteins
c) double stranded RNA
d) LPS – ANSWER- c) double stranded RNA
What event during inflammation is responsible for swelling?
a) diapedesis
b) increasing vascular permeability
c) vasodilation
d) 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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BIO 251 EXAM 3 NEWEST 2024-2025 ACTUAL EXAM
COMPLETE 100 QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS)
|ALREADY GRADED A+
An HIV positive individual with low CD4 T-cell count is infected with a
normally non-fatal virus and later dies. What likely occurred?
A. They were unable to generate antibodies through the T-dependent
pathway due to lack of helper T-cells
B. Their immune system became hyper-active through the Tindependent pathway and they died due to a cytokine storm
C. Their macrophages were unable to stimulate Helper T-cells due to
insufficient MHCII
D. They were unable to release histamine and could not mount an
inflammatory response – ANSWER- A. They were unable to generate
antibodies through the T-dependent pathway due to lack of helper Tcells
Suppose you are observing a patient who has a bacterial infection that
begins to subside fairly quickly after becoming symptomatic. An
analysis of their blood shows high levels of IgM specific to the bacteria,
but undetectable levels of IgG and IgD. Two months after being
discharged, the patient returns with another infection by the same
bacteria. What would be reasonable to conclude?
A. The patient’s immune response was coordinated via cell-mediated
toxicity
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B. The patient is immunocompromised
C. The patient’s immune reaction happened through the T-independent
pathway
D. The patient did not produce sufficient antibodies to fight off the first
infection – ANSWER- C. The patient’s immune reaction happened
through the T-independent pathway
Suppose that an antibody binds to a toxin molecule and prevents the
toxin from binding to a receptor where it would have a negative effect.
This is an example of:
Immobilization
Opsonization
Neutralization
Cross-linking – ANSWER- Neutralization
Which of the following is NOT a way that antibodies assist the immune
system in getting rid of pathogens?
A. Binding to viral coat proteins and preventing them from being able to
enter cells
B. Labeling pathogens for phagocytosis
C. Binding to flagella and fimbrae and preventing movement and
adherence.
D. Poking holes in the cell membrane and lysing bacteria directly –
ANSWER- D. Poking holes in the cell membrane and lysing bacteria
directly
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Which of the following would be an example of a PAMP?
Correct answer:
A. Peptidoglycan
B. Tissue factor
C. GaGs on the surface of eukaryotic cells
D. C3b bound to bacteria – ANSWER- A. Peptidoglycan
Match the antibody with the correct description
Antibody involved in allergic reactions
Antibody found abundantly in mucous secretions
First antibody produced in response to an infection
Antibody with poorly understood function
Antibody that penetrates the placenta
IgG
IgE
IgA
IgM
IgD – ANSWER- Antibody involved in allergic reactions
Correct match:
IgE
Antibody found abundantly in mucous secretions
Correct match:
IgA
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First antibody produced in response to an infection
Correct match:
IgM
Antibody with poorly understood function
Correct match:
IgD
Antibody that penetrates the placenta
Correct match:
IgG
What event during inflammation is responsible for swelling?
A. Vasodilation
B. Diapedesis
C. Increased sensitivity of nociceptors
D. Increasing vascular permeability – ANSWER- D. Increasing vascular
permeability
Can’t add this question for quizlet but know the names of the parts of
phagocytosis. – ANSWERPut the steps of phagocytosis in order
Chemotaxis
Engulfment (endocytosis)
Exocytosis
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