Bio 202 Exam 1 Question and Answer [2026] |
UPDATED ACTUAL Exam | Detailed Solutions
• Compare and contrast the endocrine system and the nervous system. Make sure you
understand the differences between a neurotransmitter and a hormone, addressing the
importance of receptor specificity. -✓✓ Endocrine - Uses hormones released by
endocrine glands
Effects many effector organs (i.e. HGH to all muscles)
Is slower and longer lasting
Nervous - Uses electricity and chemicals to send a fast message
Has a specific effector organ (i.e. certain muscle)
Uses neurotransmitters released by neurons
• Define negative feedback and describe its role in regulating blood levels of the various
hormones. Use an example if you like! ☺ -✓✓ Response to changed body condition
if body is high or low from normal level
signal tells body to make changes that will bring body back to normal level
once body is back
to normal level,
signal is
turned off
• List AND describe the four types of intercellular communication pathways that enable
the body to maintain homeostasis. -✓✓ - Direct communication
-- Exchange of ions and molecules between adjacent cells across gap junctions
-- Occurs between two cells of same type
-- Where have we seen these before?
-- Cardiac muscle cells
- Paracrine communication
-- Uses chemical signals to transfer information from cell to cell within single tissue
-- Most common form of intercellular communication
-- i.e. Certain growth factors
-Endocrine communication
-- Endocrine cells release chemicals (hormones) into bloodstream
-- Alters metabolic activities of many tissues and organs simultaneously
-- Analogy once again: Bulk mail - in Russian
-Synaptic communication
• Define hormone and target organ. -✓✓ Hormone - Stimulate synthesis of enzymes or
structural proteins
Increase or decrease rate of synthesis
Turn existing enzyme or membrane channel "on" or "off"
,Target organ - Are specific cells that possess receptors needed to bind and "read"
hormonal messages
• What does the "lock and key system refer to? Explain! -✓✓ hormone fits receptor on
"target" cell
• What are the three ways in which hormones are classified? Yes, you will have to which
type of chemical structure each hormone that we study falls under. For example, you
will need to know that catecholamines are amino acid derivatives. -✓✓ Amino acid
derivatives -Where have we seen amino acids before?
Peptide hormones
Lipid derivatives
Steroids
Corticosteroids/
anabolic steroids
All of these either circulate freely in the blood or are bound to transport proteins
• Compare and contrast the functionality of free vs. protein bound hormones in the
plasma (bloodstream). -✓✓ - Free Hormones
Remain functional for less than 1 hour
Diffuse out of bloodstream: bind to receptors on target cells
Are broken down and absorbed by cells of liver or kidney
Are broken down by enzymes in plasma or interstitial fluids
- Protein bound
Thyroid and Steroid Hormones
Remain in circulation much longer
Enter bloodstream
More than 99% become attached to special transport proteins
Bloodstream contains substantial reserve of bound hormones
A reserve
Why do thyroid and steroid hormones stay in circulation longer?
• Diagram the general mechanism of action of a lipid soluble hormone. Then, compare
and contrast a steroid hormone vs. thyroid hormone mechanisms of action. Yes, they
are both lipid soluble hormones, but they have slightly different mechanisms of action. -
✓✓ - Lipid soluble hormones:
Glucocorticoids
Estrogens
Androgens
Thyroid hormone (T3)
Calcitriol (the active form of vitamin _?_)
Diffuse across the plasma membrane to reach receptor proteins on inner surface of
membrane (intracellular receptors)
REMEMBER: Anything that originates from cholesterol is lipid soluble!
- Hormones and Intracellular Receptors
Alter rate of DNA transcription in nucleus
,Directly affect metabolic activity and structure of target cell
Includes steroids and thyroid hormones
Steroid - has a 4 ring structure
Lipid soluble, passes right through
Receptor is in the cell or nucleus
Thyroid hormone - lipid soluble, passes through
In nucleus - changes how DNA is read, changes what proteins that cell makes
Mitochondria has a receptor - creates energy when binded, usually really skinny and
energetic if have over producing thyroid
• Diagram the mechanism of action of a lipid insoluble hormone. Make sure to show the
second messenger systems and the role of G-proteins. -✓✓ Hormones that are NOT
lipid soluble
Catecholamins
Prolactin
Adrenocorticotropic Hormone (ACTH)
Growth Hormone
Antidiuretic Hormone (ADH) Oxytocin.
Peptide Hormones
Atrial-natriuretic Peptide (ANP)
Atrial Natriuretic Factor (ANF)
Insulin
Leptin
Unable to penetrate plasma membrane
What is the plasma membrane made of?
Bind to receptor proteins at outer surface of plasma membrane (extracellular receptors)
- Hormones and Plasma Membrane Receptors
Bind to receptors in plasma membrane
Cannot have direct effect on activities inside target cell
Use intracellular intermediary to exert effects
First messenger:
leads to second messenger
may act as enzyme activator, inhibitor, or cofactor
results in change in rates of metabolic reactions
- Important Second Messengers
Cyclic-AMP (cAMP)
Derivative of ATP
Cyclic-GMP (cGMP)
Derivative of GTP
Calcium ions
• Sketch AND explain the process of amplification in regards to the effects of hormones.
-✓✓ The Process of Amplification
Is the binding of a small number of hormone molecules to membrane receptors
Leads to thousands of second messengers in cell
, Magnifies effect of hormone on target cell
• Compare and contrast the processes of down regulation and up regulation. Use an
example that was discussed in class to support your response. -✓✓ - Down-regulation
Presence of a hormone triggers decrease in number of hormone receptors
When levels of particular hormone are high, cells become less sensitive
Receptors are all filled up
Some receptors are broken down by the target cell
- Up-regulation
Absence of a hormone triggers increase in number of hormone receptors
When levels of particular hormone are low, cells become more sensitive
Receptors are available
• If you didn't already do so, diagram the intracellular response of a steroid hormone. -
✓✓
• List AND describe the three ways that endocrine reflexes can be triggered. Provide
examples! -✓✓ Endocrine reflexes can be triggered by
- Humoral stimuli
-- Changes in composition of extracellular fluid
- Hormonal stimuli
-- Arrival or removal of specific hormone
- Neural stimuli
-- Arrival of neurotransmitters at neuroglandular junctions
• Review the locations of the organs of the endocrine system. -✓✓
• Diagram the three ways in which the hypothalamus can interact with the endocrine or
nervous system. -✓✓ Integrates activities of nervous and endocrine systems in 3 ways:
1. Acts as an endocrine organ
2. Secretes regulatory hormones:
special hormones that control endocrine cells in pituitary gland
3. Contains autonomic centers:
exert direct neural control over endocrine cells of adrenal medullae
• Draw AND label the major regions of the pituitary gland. -✓✓
• Adenohypophysis = _?_ -✓✓ Anterior pituitary
• Neurohypophysis = _?_ -✓✓ Posterior pituitary
• Compare and contrast the roles of releasing hormones and inhibiting hormones in the
hypothalamus. -✓✓ Two Classes of Hypothalamic Regulatory Hormones
Releasing hormones (RH)
Stimulate synthesis and secretion of one or more hormones at anterior lobe
UPDATED ACTUAL Exam | Detailed Solutions
• Compare and contrast the endocrine system and the nervous system. Make sure you
understand the differences between a neurotransmitter and a hormone, addressing the
importance of receptor specificity. -✓✓ Endocrine - Uses hormones released by
endocrine glands
Effects many effector organs (i.e. HGH to all muscles)
Is slower and longer lasting
Nervous - Uses electricity and chemicals to send a fast message
Has a specific effector organ (i.e. certain muscle)
Uses neurotransmitters released by neurons
• Define negative feedback and describe its role in regulating blood levels of the various
hormones. Use an example if you like! ☺ -✓✓ Response to changed body condition
if body is high or low from normal level
signal tells body to make changes that will bring body back to normal level
once body is back
to normal level,
signal is
turned off
• List AND describe the four types of intercellular communication pathways that enable
the body to maintain homeostasis. -✓✓ - Direct communication
-- Exchange of ions and molecules between adjacent cells across gap junctions
-- Occurs between two cells of same type
-- Where have we seen these before?
-- Cardiac muscle cells
- Paracrine communication
-- Uses chemical signals to transfer information from cell to cell within single tissue
-- Most common form of intercellular communication
-- i.e. Certain growth factors
-Endocrine communication
-- Endocrine cells release chemicals (hormones) into bloodstream
-- Alters metabolic activities of many tissues and organs simultaneously
-- Analogy once again: Bulk mail - in Russian
-Synaptic communication
• Define hormone and target organ. -✓✓ Hormone - Stimulate synthesis of enzymes or
structural proteins
Increase or decrease rate of synthesis
Turn existing enzyme or membrane channel "on" or "off"
,Target organ - Are specific cells that possess receptors needed to bind and "read"
hormonal messages
• What does the "lock and key system refer to? Explain! -✓✓ hormone fits receptor on
"target" cell
• What are the three ways in which hormones are classified? Yes, you will have to which
type of chemical structure each hormone that we study falls under. For example, you
will need to know that catecholamines are amino acid derivatives. -✓✓ Amino acid
derivatives -Where have we seen amino acids before?
Peptide hormones
Lipid derivatives
Steroids
Corticosteroids/
anabolic steroids
All of these either circulate freely in the blood or are bound to transport proteins
• Compare and contrast the functionality of free vs. protein bound hormones in the
plasma (bloodstream). -✓✓ - Free Hormones
Remain functional for less than 1 hour
Diffuse out of bloodstream: bind to receptors on target cells
Are broken down and absorbed by cells of liver or kidney
Are broken down by enzymes in plasma or interstitial fluids
- Protein bound
Thyroid and Steroid Hormones
Remain in circulation much longer
Enter bloodstream
More than 99% become attached to special transport proteins
Bloodstream contains substantial reserve of bound hormones
A reserve
Why do thyroid and steroid hormones stay in circulation longer?
• Diagram the general mechanism of action of a lipid soluble hormone. Then, compare
and contrast a steroid hormone vs. thyroid hormone mechanisms of action. Yes, they
are both lipid soluble hormones, but they have slightly different mechanisms of action. -
✓✓ - Lipid soluble hormones:
Glucocorticoids
Estrogens
Androgens
Thyroid hormone (T3)
Calcitriol (the active form of vitamin _?_)
Diffuse across the plasma membrane to reach receptor proteins on inner surface of
membrane (intracellular receptors)
REMEMBER: Anything that originates from cholesterol is lipid soluble!
- Hormones and Intracellular Receptors
Alter rate of DNA transcription in nucleus
,Directly affect metabolic activity and structure of target cell
Includes steroids and thyroid hormones
Steroid - has a 4 ring structure
Lipid soluble, passes right through
Receptor is in the cell or nucleus
Thyroid hormone - lipid soluble, passes through
In nucleus - changes how DNA is read, changes what proteins that cell makes
Mitochondria has a receptor - creates energy when binded, usually really skinny and
energetic if have over producing thyroid
• Diagram the mechanism of action of a lipid insoluble hormone. Make sure to show the
second messenger systems and the role of G-proteins. -✓✓ Hormones that are NOT
lipid soluble
Catecholamins
Prolactin
Adrenocorticotropic Hormone (ACTH)
Growth Hormone
Antidiuretic Hormone (ADH) Oxytocin.
Peptide Hormones
Atrial-natriuretic Peptide (ANP)
Atrial Natriuretic Factor (ANF)
Insulin
Leptin
Unable to penetrate plasma membrane
What is the plasma membrane made of?
Bind to receptor proteins at outer surface of plasma membrane (extracellular receptors)
- Hormones and Plasma Membrane Receptors
Bind to receptors in plasma membrane
Cannot have direct effect on activities inside target cell
Use intracellular intermediary to exert effects
First messenger:
leads to second messenger
may act as enzyme activator, inhibitor, or cofactor
results in change in rates of metabolic reactions
- Important Second Messengers
Cyclic-AMP (cAMP)
Derivative of ATP
Cyclic-GMP (cGMP)
Derivative of GTP
Calcium ions
• Sketch AND explain the process of amplification in regards to the effects of hormones.
-✓✓ The Process of Amplification
Is the binding of a small number of hormone molecules to membrane receptors
Leads to thousands of second messengers in cell
, Magnifies effect of hormone on target cell
• Compare and contrast the processes of down regulation and up regulation. Use an
example that was discussed in class to support your response. -✓✓ - Down-regulation
Presence of a hormone triggers decrease in number of hormone receptors
When levels of particular hormone are high, cells become less sensitive
Receptors are all filled up
Some receptors are broken down by the target cell
- Up-regulation
Absence of a hormone triggers increase in number of hormone receptors
When levels of particular hormone are low, cells become more sensitive
Receptors are available
• If you didn't already do so, diagram the intracellular response of a steroid hormone. -
✓✓
• List AND describe the three ways that endocrine reflexes can be triggered. Provide
examples! -✓✓ Endocrine reflexes can be triggered by
- Humoral stimuli
-- Changes in composition of extracellular fluid
- Hormonal stimuli
-- Arrival or removal of specific hormone
- Neural stimuli
-- Arrival of neurotransmitters at neuroglandular junctions
• Review the locations of the organs of the endocrine system. -✓✓
• Diagram the three ways in which the hypothalamus can interact with the endocrine or
nervous system. -✓✓ Integrates activities of nervous and endocrine systems in 3 ways:
1. Acts as an endocrine organ
2. Secretes regulatory hormones:
special hormones that control endocrine cells in pituitary gland
3. Contains autonomic centers:
exert direct neural control over endocrine cells of adrenal medullae
• Draw AND label the major regions of the pituitary gland. -✓✓
• Adenohypophysis = _?_ -✓✓ Anterior pituitary
• Neurohypophysis = _?_ -✓✓ Posterior pituitary
• Compare and contrast the roles of releasing hormones and inhibiting hormones in the
hypothalamus. -✓✓ Two Classes of Hypothalamic Regulatory Hormones
Releasing hormones (RH)
Stimulate synthesis and secretion of one or more hormones at anterior lobe
