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BIOS255 Comprehensive Exam Review (Latest Update 2026
/ 2027) Questions with Answers | Grade A | 100% Correct
Homeostasis - ANSWER * Presence of stable internal
environment
* Failure to maintain homeostasis leads to illness or death
Homeostatic Regulation - ANSWER Physiological adjustment to
preserve homeostasis in variable environments
Feedback - ANSWER Stimulation of a receptor triggers response
that changes environment at that receptor
Negative Feedback - ANSWER * Effector opposes or negates the
original stimulus
* Minimizes change
* Primary mechanism of homeostatic regulation in the body
* Dynamic process: Set point varies with varying environments
& activity levels
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Negative Feedback Receptors - ANSWER Temperature receptors
in skin & brain are stimulated & send signals to the control
center
Negative Feedback Control Center - ANSWER The temperature
control center received information from the two sets of
temperature receptors & sends commands to the effectors
Negative Feedback Effectors - ANSWER Sweat glands & smooth
muscle in the walls of blood vessels supplying the skin respond
Positive Feedback - ANSWER * Stimulus produces a response
that exaggerates or enhances the original change (rather than
opposing it)
* Tends to produce extreme responses
* Does not restore homeostasis
Positive Feedback Loop - ANSWER * Escalating cycle
* Typically occurs when a potentially dangerous or stressful
process must be completed quickly before the body can restore
homeostasis
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Steps of Positive Feedback in Blood Clotting - ANSWER 1.
Damage to cells in the blood vessel wall releases chemicals that
begin the process of blood clotting
2. The chemicals start chain reactions in which cells, cell
fragments, & soluble proteins in the blood begin to form a clot
3. As clotting continues, each step releases chemicals that
further accelerate the process
4. This escalating process is a positive feedback loop that ends
with the formation of a blood clot, which patches the vessel
wall & stops the bleeding
Epithelial Tissue - ANSWER * Epithelia
* Glands (Exocrine & Endocrine)
Functions of Epithelial Tissue - ANSWER * Provide physical
protection
* Control permeability
* Provide sensation
* Produce specialized secretions
BIOS255 Comprehensive Exam Review (Latest Update 2026
/ 2027) Questions with Answers | Grade A | 100% Correct
Homeostasis - ANSWER * Presence of stable internal
environment
* Failure to maintain homeostasis leads to illness or death
Homeostatic Regulation - ANSWER Physiological adjustment to
preserve homeostasis in variable environments
Feedback - ANSWER Stimulation of a receptor triggers response
that changes environment at that receptor
Negative Feedback - ANSWER * Effector opposes or negates the
original stimulus
* Minimizes change
* Primary mechanism of homeostatic regulation in the body
* Dynamic process: Set point varies with varying environments
& activity levels
,2|Page
Negative Feedback Receptors - ANSWER Temperature receptors
in skin & brain are stimulated & send signals to the control
center
Negative Feedback Control Center - ANSWER The temperature
control center received information from the two sets of
temperature receptors & sends commands to the effectors
Negative Feedback Effectors - ANSWER Sweat glands & smooth
muscle in the walls of blood vessels supplying the skin respond
Positive Feedback - ANSWER * Stimulus produces a response
that exaggerates or enhances the original change (rather than
opposing it)
* Tends to produce extreme responses
* Does not restore homeostasis
Positive Feedback Loop - ANSWER * Escalating cycle
* Typically occurs when a potentially dangerous or stressful
process must be completed quickly before the body can restore
homeostasis
, 3|Page
Steps of Positive Feedback in Blood Clotting - ANSWER 1.
Damage to cells in the blood vessel wall releases chemicals that
begin the process of blood clotting
2. The chemicals start chain reactions in which cells, cell
fragments, & soluble proteins in the blood begin to form a clot
3. As clotting continues, each step releases chemicals that
further accelerate the process
4. This escalating process is a positive feedback loop that ends
with the formation of a blood clot, which patches the vessel
wall & stops the bleeding
Epithelial Tissue - ANSWER * Epithelia
* Glands (Exocrine & Endocrine)
Functions of Epithelial Tissue - ANSWER * Provide physical
protection
* Control permeability
* Provide sensation
* Produce specialized secretions
