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BIOL 252 HUMAN PSYCHOOGY EXAM LATEST UPDATE -
2025/2026- 100+ QUESTIONS AND VERIFIED ANSWERS ALL
THE BEST
What is a positive feedback mechanism?
A response that increases the deviation from the set point
Which mechanism is more common and why?
Negative feedback; they bring us closer to homeostasis
When may a positive feedback mechanism be deplyed?
Childbirth, opening of sodium channels with action potentials, or platelet-plug
formation during blood clotting.
What do receptors do in feedback loops?
Monitor the value of some variable and send information to the
control/integrating center.
What does the control/integrating center do in feedback loops?
Establishes the set point and compares incoming information to that set point.
What does the effector do in feedback loops?
Take signals from the control center and change activity to change the variable.
Why is there a limit to how large a cell can be?
They're limited by the ratio of surface area to volume; Because smaller cells are
more efficient; cell volume increases exponentially
What aspect of increasing a cell's size is the limiting factor?
Volume
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What is the basic function of the plasma membrane?
Defines the boundaries of the cell, controls cell interactions, and controls the
movement of materials in and out of the cell.
Why does the plasma membrane appear as a dark set of parallel lines under a
microscope?
The membrane is composed of a bilayer of phospholipids with some intracellular
fluid in the space between the layers.
What kind of lipids are found in the plasma membrane?
Phospholipids, cholesterol, and glycolipids.
How much of the plasma membrane is made up by phospholipids?
About 75%
How much of the plasma membrane is made up by cholesterol?
About 20%
How much of the plasma membrane is made up by glycolipids?
About 5%
What is the function of glycolipids in the cell membrane?
They help form the glycocalyx, which helps the body distinguish its healthy cells
from transported cells, diseases, or invading organisms.
What is anatomy?
The study of the structure of living organisms.
What is physiology?
The study of how living organisms function.
What are some examples of physiological variation amongst individuals?
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Age, genetics, diet, weight, physical activity, and the environment.
What is homeostasis?
A relatively constant internal environment
What are some factors that must be maintained via homeostasis?
Heart rate, body temperature, blood pressure, etc.
What are the components of homeostasis?
Receptors, control/integrating center, and effectors.
What is a negative feedback mechanism?
A response that makes deviation from the set point smaller--resisting change
What is the function of glycoproteins in the cell membrane?
Cell identity markers; They help form the glycocalyx, which helps the body
distinguish its healthy cells from transported cells, diseases, or invading
organisms.
What are the two categories of membrane proteins?
Integral (transmembrane) and peripheral
What are integral (transmembrane) proteins?
Span the inside of the cell on the phospholipid bilayer
What are peripheral proteins?
Bound to the surface of the cell membrane
What are the four categories of proteins based on function?
Receptors, enzymes, channel proteins, and carrier proteins
What do receptor proteins do?
BIOL 252 HUMAN PSYCHOOGY EXAM LATEST UPDATE -
2025/2026- 100+ QUESTIONS AND VERIFIED ANSWERS ALL
THE BEST
What is a positive feedback mechanism?
A response that increases the deviation from the set point
Which mechanism is more common and why?
Negative feedback; they bring us closer to homeostasis
When may a positive feedback mechanism be deplyed?
Childbirth, opening of sodium channels with action potentials, or platelet-plug
formation during blood clotting.
What do receptors do in feedback loops?
Monitor the value of some variable and send information to the
control/integrating center.
What does the control/integrating center do in feedback loops?
Establishes the set point and compares incoming information to that set point.
What does the effector do in feedback loops?
Take signals from the control center and change activity to change the variable.
Why is there a limit to how large a cell can be?
They're limited by the ratio of surface area to volume; Because smaller cells are
more efficient; cell volume increases exponentially
What aspect of increasing a cell's size is the limiting factor?
Volume
, 2
What is the basic function of the plasma membrane?
Defines the boundaries of the cell, controls cell interactions, and controls the
movement of materials in and out of the cell.
Why does the plasma membrane appear as a dark set of parallel lines under a
microscope?
The membrane is composed of a bilayer of phospholipids with some intracellular
fluid in the space between the layers.
What kind of lipids are found in the plasma membrane?
Phospholipids, cholesterol, and glycolipids.
How much of the plasma membrane is made up by phospholipids?
About 75%
How much of the plasma membrane is made up by cholesterol?
About 20%
How much of the plasma membrane is made up by glycolipids?
About 5%
What is the function of glycolipids in the cell membrane?
They help form the glycocalyx, which helps the body distinguish its healthy cells
from transported cells, diseases, or invading organisms.
What is anatomy?
The study of the structure of living organisms.
What is physiology?
The study of how living organisms function.
What are some examples of physiological variation amongst individuals?
, 3
Age, genetics, diet, weight, physical activity, and the environment.
What is homeostasis?
A relatively constant internal environment
What are some factors that must be maintained via homeostasis?
Heart rate, body temperature, blood pressure, etc.
What are the components of homeostasis?
Receptors, control/integrating center, and effectors.
What is a negative feedback mechanism?
A response that makes deviation from the set point smaller--resisting change
What is the function of glycoproteins in the cell membrane?
Cell identity markers; They help form the glycocalyx, which helps the body
distinguish its healthy cells from transported cells, diseases, or invading
organisms.
What are the two categories of membrane proteins?
Integral (transmembrane) and peripheral
What are integral (transmembrane) proteins?
Span the inside of the cell on the phospholipid bilayer
What are peripheral proteins?
Bound to the surface of the cell membrane
What are the four categories of proteins based on function?
Receptors, enzymes, channel proteins, and carrier proteins
What do receptor proteins do?
