Biology
Name _____________________________
HOMEOSTASIS STANDARD 3: Feedback & Chemical Processes (HMS3)
How do we maintain internal balance?!!
POWERSTANDARD/HOMESTASIS:
Students will be able to convey an understanding of how the external environment
affects the internal environment of an organism and explain how dynamic equilibrium (homeostasis) is maintained within a living
system normally and during stress.
STANDARD HMS3/ Feedback & Chemical Processes: Students will convey a conceptual understanding of
how homeostasis is maintained by explaining feedback mechanisms, including the roll of chemicals within homeostatic loops.
TASK/EXAM: Demonstrate conceptual understanding in an exam format that includes short and extended responses.
STANDARD HMS3/ Feedback &
Chemical Processes: Students will
convey a conceptual understanding of how
homeostasis is maintained by explaining the roll
of chemicals and reactions in feedback
mechanisms.
RUBRIC: Demonstrate the following skills during an in-class exam…
4 – Exceeding
3 – Meeting
Complete all requirements for MEETING (3)
and…
includes some combination of the
following:
o All questions are completely correct
o Some responses demonstrate greater
understanding than required for this class
(particularly in extended responses)
o Greater understanding demonstrated in
the evolutionary tree diagrams
All exam questions are correct
though answers may show minor
errors that do not affect
conceptual understanding.
Demonstrate conceptual
understanding of the content
listed below in the practice
questions.
2 – Approaching
1 – Beginning
Most exam questions are
correct but one or more
answers shows errors that
demonstrate
misconceptions and/or lack
of understanding.
Most exam questions are
attempted but some to
zero exam questions are
correct. One or more
answers show errors that
demonstrate
misconceptions and/or lack
of understanding.
HMS3 SYLLABUS
Approximate #
of days
Science Take-Out: Keeping the Balance
DAY 1
PART 1- Homeostasis & Negative Feedback
Science Take-Out: Keeping the Balance
DAY 1
HW
PART 2- Regulating Sugar Concentration in Cupples
BSCS Essay: Homeostasis (p.233-235)
VL
Bozeman Biology: Homeostatic Hugs [8:34]
Science Take-Out: Keeping the Balance
DAY 2
PART 3-Negative Feedback and Body Temperature
Science Take-Out: Keeping the Balance
DAY 2
HW
PART 4- Negative Feedback and Blood Glucose
BSCS Essay: Beyond the Limits (p.246-248)
VL
Bozeman Biology: Homeostatic Loops [8:50]
Science Take-Out: Keeping the Balance
DAY 3
CONTENT
Activity, Classwork, & Homework Assignments
PART 5-Fishbowl Analogy for Homeostasis
DAY 3
BSCS Essay: Careful Coordination (p.235-240)
HW
DAY 4
BSCS Essay: Behavior and Homeostasis (p.243-245)
Completed
Homeostasis, negative feedback mechanisms, set point,
introduction to negative feedback graphic organizer
Blood sugar simulation in fictitious organism (the Cupple)
Homeostasis, stimuli, responses (voluntary & involuntary)
hugs between tissues maintain homeostasis, countercurrent heat
exchange, capillaries hug alveoli and tubules in the nephron
Regulating body temperature, reading a graph to determine
homeostatic balance, negative feedback graphic organizer
Regulating blood glucose, insulin, glucagon, blood glucose
Stressors, maintaining homeostasis
Homeostatic loops, hypothalamus role in internal body temperature,
pancreas role in regulating blood glucose, plus more!
Ability to understand an analogy (fishbowl analogy)
Hormones, receptors, transmitter, reflex & reflex arc, AND feedback
utilizing organ systems: nervous, endocrine, respiratory, circulatory
external behaviors affect internal homeostasis
HMS3 EXAM
Review QUESTIONS:
Organisms are continually exposed to changes in their external and internal environments. To be healthy, organisms must maintain homeostasis, a “dynamic
equilibrium” or “steady state,” which keeps their internal environment balanced within normal limits. Failure to maintain homeostasis may result in disease or death.
To maintain homeostasis, organisms use negative feedback mechanisms that detect changes from the set point, (the normal state) and trigger appropriate responses
that return their body systems to the set point.
1.
2.
Use the information in the box above to write definitions for the following words:
a.
Homeostasis
b.
Negative feedback mechanism
c.
Set point
Why are feedback mechanisms important?
Biology
3.
Name _____________________________
The process of homeostasis is like driving a car at the speed limit (55 miles per hour).
a.
What is the set point for driving a car?
b.
If you detect that the speed of the car is above the set point, what response should you make?
c.
If you detect the speed of the car is below the set point, what response should you make?
4.
What are three homeostatic responses to being overly hot (elevated body temperature) such as having a fever?
5.
What are three homeostatic responses to being overly cold (reduced body temperature) such as being hypothermic?
6.
Match each event in the table with the generic description below:
i.
Detects above normal state
ii.
Controls center triggers response
iii.
Effect of response from a & b
iv.
Detects below normal state
v.
Control center triggers response
vi.
Effect of d & e
A
B
C
Hypothalamus signals cause muscles to
shiver and blood vessels to constrict.
Hypothalamus detects decrease in body
temperature.
Hypothalamus detects increase in body
temperature.
D
E
F
Sweating and dilation of skin blood vessels
decreases body temperature.
Hypothalamus signals cause sweat
production and skin blood vessel dilation.
Shivering and blood vessel constriction
increases body temperature.
7.
Read the case study on Blood Glucose. Fill in the diagram below, showing how blood glucose is regulated in extreme
conditions. Be sure to have written a response to 1-4 and also to have filled in the two boxes.
Blood Glucose Homeostasis
The concentration of glucose in the blood affects every cell in the body. Therefore, its concentration is strictly controlled within the range
80-100 mg of glucose per 100 ml of blood. Very low levels of blood glucose or very high levels of blood glucose are both serious conditions and
can lead to death. Blood glucose concentration is controlled by the pancreas. The pancreas has glucose receptor cells, which monitor the
concentration of glucose in the blood, and it also has endocrine cells which secrete the hormones insulin and glucagon. These two hormones
have opposite effects on blood glucose. Glucagon stimulates the release of stored glucose from the liver which increases blood glucose levels.
Insulin stimulates the uptake of glucose by cells which decreases blood glucose levels.
After a meal, glucose is absorbed from the digestive tract and glucose concentration in blood increases. This increase is detected by the
pancreas, which responds by secreting insulin. Insulin causes glucose to be taken up by the body cells. This reduces blood glucose, which
causes the pancreas to stop secreting insulin. If the glucose level decreases too much, the pancreas detects this change and responds by
secreting the hormone glucagon. Glucagon causes the release of stored glucose from the liver. This increases blood glucose, which causes the
pancreas to stop producing glucagon.
IF glucose levels…
2
1
Regulating
Blood
Glucose
3
IF glucose levels…
4