Physiology/Biodiversity Unit – USE YOUR NOTEBOOK
What you should know:
Enduring understanding 2.C: Organisms use feedback mechanisms to regulate growth and
reproduction, and to maintain dynamic homeostasis.
Essential knowledge 2.C.1: Organisms use feedback mechanisms to maintain their internal
environments and respond to external environmental changes.
a. Negative feedback mechanisms maintain dynamic homeostasis for a particular condition
(variable) by regulating physiological processes, returning the changing condition back to its target
set point.
To demonstrate student understanding of this concept, make sure you can explain the following:
● Temperature regulation in animals
● Plant responses to water limitations
b. Positive feedback mechanisms amplify responses and processes in biological organisms. The
variable initiating the response is moved farther away from the initial set-point. Amplification
occurs when the stimulus is further activated which, in turn, initiates an additional response that
produces system change.
To demonstrate student understanding of this concept, make sure you can explain the following:
● Lactation in mammals
● Onset of labor in childbirth
● Ripening of fruit
c. Alteration in the mechanisms of feedback often results in deleterious consequences.
To demonstrate student understanding of this concept, make sure you can explain the following:
● Diabetes mellitus in response to decreased insulin
● Dehydration in response to decreased antidiuretic hormone (ADH)
● Graves’ disease (hyperthyroidism)
● Blood clotting
What you should do:
1. How do negative feedback mechanisms work to maintain dynamic homeostasis for a
particular condition? Focus your answer using the following examples:
○ Temperature regulation in animals (use the feedback loop on humans as your
example as well as one ectotherm) ***Found at the end of the Lab 10 – Lab Bench
○ Plant responses to water limitations (focus on stomates)
2. How do Positive feedback mechanisms work to maintain dynamic homeostasis for a
particular condition? Focus your answer using the following examples: (use your table from
the student presentations)
o Lactation in mammals
o Onset of labor in childbirth
o Ripening of fruit
3. Explain the effects of alteration in the mechanisms of feedback. Use the following to help
illustrate your explanation:
○ Diabetes mellitus in response to decreased insulin
○ Dehydration in response to decreased antidiuretic hormone (ADH)
○ Graves’ disease (hyperthyroidism)
○ Blood clotting
What you should know:
Enduring understanding 2.D: Growth and dynamic homeostasis of a biological system are
influenced by changes in the system’s environment.
Essential knowledge 2.D.2: Homeostatic mechanisms reflect both common ancestry and
divergence due to adaptation in different environments.
a. Continuity of homeostatic mechanisms reflects common ancestry, while changes may occur in
response to different environmental conditions.
b. Organisms have various mechanisms for obtaining nutrients and eliminating wastes.
To demonstrate student understanding of this concept, make sure you can explain the following:
● Gas exchange in aquatic and terrestrial plants
● Respiratory systems of aquatic and terrestrial animals
c. Homeostatic control systems in species of microbes, plants and animals support common
ancestry.
To demonstrate student understanding of this concept, make sure you can explain the following:
● Osmoregulation in bacteria, fish and protists (think cell membrane, gills, contractile vacuole)
● Osmoregulation in aquatic and terrestrial plants
● Circulatory systems in fish, amphibians and mammals
● Thermoregulation in aquatic and terrestrial animals (countercurrent exchange mechanisms)
What you should do:
1. How do homeostatic mechanisms support common ancestry and how do changes in the
environment drive divergence from the common ancestor? (A good example is thinking
about the evolution of the heart from two to four chambers.)
2. Explain how the following mechanisms are used for obtaining nutrients and eliminating
wastes.
○ Gas exchange in aquatic and terrestrial plants
○ Respiratory systems of aquatic and terrestrial animals
3. Explain how homeostatic control systems in species of microbes, plants and animals
support common ancestry. Use the following to help illustrate your explanation:
○ Osmoregulation in bacteria, fish and protists (think cell membrane, gills,
contractile vacuole)
○ Osmoregulation in aquatic and terrestrial plants
○ Circulatory systems in fish, amphibians and mammals
○ Thermoregulation in aquatic and terrestrial animals (countercurrent exchange
mechanisms)
What you should know:
Enduring understanding 4.A: Interactions within biological systems lead to complex
properties.
Essential knowledge 4.A.4: Organisms exhibit complex properties due to interactions
between their constituent parts.
a. Interactions and coordination between organs provide essential biological activities.
To demonstrate student understanding of this concept, make sure you can explain the following:
● Root, stem and leaf
b. Interactions and coordination between systems provide essential biological activities.
To demonstrate student understanding of this concept, make sure you can explain the following:
● Respiratory and circulatory
● Nervous and muscular
● Plant vascular and leaf
What you should do:
1. Use the following examples to discuss the importance of Interactions and coordination
between organs.
○ Root, stem and leaf
2. Using the following examples to discuss the importance of Interactions and coordination
between systems
○ Respiratory and circulatory
○ Nervous and muscular
○ Plant vascular and leaf
What you should know:
Enduring understanding 4.B: Competition and cooperation are important aspects of
biological systems.
Essential knowledge 4.B.2: Cooperative interactions within organisms promote efficiency in
the use of energy and matter.
a. Organisms have areas or compartments that perform a subset of functions related to energy and
matter, and these parts contribute to the whole.
To demonstrate student understanding of this concept, make sure you can explain the following:
1. At the cellular level, the plasma membrane, cytoplasm and, for eukaryotes, the organelles
contribute to the overall specialization and functioning of the cell.
2. Within multicellular organisms, specialization of organs contributes to the overall functioning of
the organism.
To demonstrate student understanding of this concept, make sure you can explain the following:
● Exchange of gases
● Circulation of fluids
● Digestion of food
● Excretion of wastes
3. Interactions among cells of a population of unicellular organisms can be similar to those of
multicellular organisms, and these interactions lead to increased efficiency and utilization of energy
and matter.
To demonstrate student understanding of this concept, make sure you can explain the following:
● Bacterial community in the rumen of animals
● Bacterial community in and around deep sea vents
What you should do:
1. For the unicellular organisms listed below, explain how the specialization of the plasma
membrane, cytoplasm and any applicable organelles contribute to the bulleted processes.
BACTERIA, PROTIST
○ Circulation of fluids
○ Digestion of food
○ Excretion of wastes
2.
For the multicellular organisms listed below, explain how the specialization of the organs
contribute to the circulation of fluids.
GRASSHOPPER, FROG, FISH, PLANT
3. Using the examples below to explain how Interactions among cells of a population of
unicellular organisms can be similar to those of multicellular organisms, and these
interactions lead to increased efficiency and utilization of energy and matter.
○ Bacterial community in the rumen of animals
○ Bacterial community in and around deep sea vents