Successful transition to a positive feedback cooling loop.
Achievement of the final set point for athletic performance.
Complete shutdown of the nervous system control center.
Part III: System Scenarios
7. PTH hormone release from the parathyroid raises blood calcium when it is low. This is:
DOK 2 | B.1.2
Negative feedback because the response reverses the stimulus (low Ca).
Positive feedback because it adds minerals to the bloodstream.
A failure of the skeletal system to maintain bone density.
A reflex arc that does not require an endocrine signal.
8. Why must positive feedback loops (like clotting) have an "off-switch"?
DOK 2 | B.1.2
To prevent the response from amplifying until catastrophic failure occurs.
Because the body lacks enough ATP to run them for more than an hour.
To allow the brain to switch to negative feedback for healing.
Because they only function properly in cold environments.
9. Concentrated urine in a hiker shows the endocrine system signaling the _______ to ________ water.
DOK 3 | B.1.3
Kidneys (Excretory) / Reabsorb
Stomach (Digestive) / Release
Heart (Circulatory) / Store
Muscles (Muscular) / Heat
10. Blood pH below 7.35 denatures enzymes. This disrupts cellular homeostasis by:
DOK 2 | B.1.2
Changing protein shape, stopping vital chemical reactions.
Increasing the speed of ATP production in the mitochondria.
Blocking all water from entering the cell membrane.
Turning the tissue level into an independent organism.
11. Why is neural shivering faster than hormonal metabolism changes?
DOK 2 | B.1.2
Electrical impulses travel faster than chemicals in the bloodstream.
Nerves are physically larger and easier for the brain to find.
Hormones only work while an organism is standing still.
The endocrine system requires light to activate its signals.
12. Active transport of K+ into a cell requires ATP because:
DOK 2 | B.1.4
Ions are being pumped against their concentration gradient.
Osmosis is naturally too slow to maintain cellular balance.
The ions are too heavy to move through the cytoplasm otherwise.
Energy is needed to build a new cell wall for each ion.
13. Closing stomata during a drought is a trade-off because:
DOK 3 | B.1.1
Limiting gas exchange (CO2) slows down photosynthesis.
The plant loses the ability to absorb water from the soil.
The cell walls in the leaves will burst from pressure.
The plant must use its skeletal system for structural support.
14. Vasoconstriction in the skin occurs when cold. The Hypothalamus acts as the:
DOK 2 | B.1.2
Control Center
Effector
Stimulus
Pathway
Part IV: Advanced System Detail
15. High altitude triggers extra RBC production. This is at which levels?
DOK 3 | B.1.2
Tissue (blood) and System (circulatory).
Only the atom level within the lungs.
The organism level bypassing all tissues.
The organ system level of the digestive tract.
16. Multi-Select: Select TWO symptoms of a failed glucose negative feedback loop.
DOK 2 | B.1.2
Hyperglycemia (High blood sugar)
Cellular Fatigue (Low internal energy)
Increased Muscle Mass
Enhanced Hearing and Sight
17. IV drip of distilled water causes RBCs to swell/burst because:
DOK 3 | B.1.4
Water moves by osmosis into cells (high to low water conc).
Distilled water is toxic to the hemoglobin protein.
Blood vessels stop working when salt levels are zero.
The brain tells the cells to absorb more water for energy.
18. High humidity makes cooling harder because:
DOK 3 | B.1.2
Sweat cannot evaporate to remove heat from the skin surface.
Wet air blocks the nervous system from reading the skin's temp.
Humidity causes blood vessels to switch to positive feedback.
Moisture in the air provides extra ATP for the muscles.
19. Which system is the effector in blood pressure regulation?
DOK 2 | B.1.3
The heart (Circulatory system).
The sensors in the arteries (Receptors).
The brain stem (Control Center).
Gravity (External Stimulus).
20. Cochlear implants restore hearing by bypassing damaged ________ to signal the brain.
DOK 2 | B.1.2
Receptors (Sensory cells).
Effectors (Muscle cells).
Signals (Electrical waves).
Stimuli (Sound waves).
21. Insulin resistance in Type 2 diabetes is a failure of the:
DOK 3 | B.1.2
Effector response.
Control Center production.
Receptor detection.
Digestive breakdown.
22. Reflex arcs (pulling hand from heat) bypass the brain to protect tissue. This is:
DOK 2 | B.1.2
A rapid negative feedback loop for integrity.
A failure of the nervous system's control center.
A slow-acting endocrine response to energy.
A positive feedback loop that increases heat.
23. Liver failure prevents glycogen storage. Predict the metabolic state between meals.
DOK 3 | B.1.2
Rapid hypoglycemia (low sugar) due to lack of reserves.
Permanent hyperglycemia because sugar stays in blood.
Normal sugar levels, as the lungs will store the energy.
Increased energy from using protein directly for ATP.
24. Lymphatic systems return excess fluid to blood to maintain:
DOK 2 | B.1.3
Fluid and blood volume homeostasis.
Skeletal marrow density.
Digestive breakdown of fats.
The speed of neural electrical impulses.
25. Adrenaline signal from Endocrine affects the ________ system effector (heart).
DOK 2 | B.1.3
Circulatory
Respiratory
Excretory
Skeletal
26. Shivering increases body heat. Muscle is the:
DOK 1 | B.1.2
Effector
Receptor
Stimulus
Loop
27. Semi-permeable membranes maintain gradients. This is:
DOK 2 | B.1.4
Dynamic Equilibrium (Homeostasis).
Static Organization.
Positive Feedback release.
System isolation.
28. Which level has specialized cells working for a single function?
DOK 1 | B.1.1
Tissue
Organ
System
Organism
Part V: Constructed Response
| Min | State | pH | Rate |
|---|---|---|---|
| 0 | Rest | 7.42 | 12 |
| 10 | Peak | 7.22 | 42 |
| 25 | Recov | 7.38 | 16 |
Breaths / Min (0-50)
29. Construct a CER to explain how the respiratory system restores blood pH. Cite specific data points.
Glucose (mg/dL)
Hours After Meal
0
300
012345
Normal Response
Patient A (Type 2)
30. Use CER to explain Patient A's loop failure and predict their metabolic state 5 hours post-meal.
It attracts nitrogen atoms to build new proteins.
8. Insulin acts as a protein signal in a feedback loop. What is its specific role?
DOK 2 | B.1.2
It binds to membrane receptors to trigger glucose channel opening.
It breaks down polysaccharides directly in the bloodstream.
It serves as the receptor that detects high blood pressure.
9. Pancreas releases glucagon when blood sugar is low. Identify the effector and response.
DOK 2 | B.1.2
Liver (effector) breaks down glycogen to release glucose (response).
Muscle (effector) absorbs glucose to store energy (response).
10. Why does active transport require ATP (energy)?
DOK 2 | B.1.4
It moves molecules from low to high concentration, against the gradient.
It moves molecules from high to low concentration, with the gradient.
Part IV: Advanced Scenarios
11. Which two systems deliver glucose to cells and remove CO2 waste?
DOK 2 | B.1.3
Circulatory and Respiratory
Excretory and Nervous
Skeletal and Muscular
12. DOK 3: Why is shivering considered a negative feedback response?
DOK 3 | B.1.2
It uses muscle activity to generate heat, counteracting the stimulus of cold.
It signals the brain to store more lipids for insulation.
13. Lasik surgery reshapes the cornea (tissue). This supports organism-level sensing by improving which level of organization?
DOK 2 | B.1.1
Organ (Eye)
System (Nervous)
Cellular
14. A cochlear implant acts as an artificial sensor. Which part of the feedback loop does it replace?
DOK 2 | B.1.2
Receptor
Effector
Control Center
15. Type 2 Diabetes means protein receptors on the cell membrane no longer respond to the signal. Which macromolecule class is the signal?
DOK 2 | B.1.2
Insulin (Protein)
Glucose (Carbohydrate)
DNA (Nucleic Acid)
16. Which macromolecule provides the immediate fuel for cellular respiration to produce ATP?
DOK 1 | B.2.1
Glucose (Carbohydrate)
Triglyceride (Lipid)
17. Phosphorus is an essential atom found in which two macromolecule classes?
DOK 2 | B.2.1
Lipids and Nucleic Acids
Proteins and Carbohydrates
18. DNA in the nucleus is protected by a double layer of lipids. This barrier represents which level?
DOK 2 | B.1.1
Cellular/Organelle
Tissue
19. Which system interacts with digestion to move absorbed carbohydrates to the liver?
DOK 2 | B.1.3
Circulatory
Skeletal
20. DOK 3: Predict the effect of a lipid-deficient diet on cell signaling.
DOK 3 | B.1.4
Receptor proteins on the membrane may be unstable, preventing signal reception.
The cell will switch to using nucleic acids as the primary barrier.
21. Adipose tissue stores lipids for energy. This is released when:
DOK 2 | B.1.2
Glucose levels are low and fuel is needed for ATP.
Insulin levels are high.
22. When blood pH drops (acidity), the brain signals lungs to breathe faster. Level?
DOK 2 | B.1.1
Organ System/Organism
Atomic
23. DOK 3: Why is glucose essential for active transport in the kidneys?
DOK 3 | B.1.4
It is the fuel for ATP production needed for protein pumps.
It binds to lipids to solidify the membrane.
24. Which atom is essential for the nitrogenous bases of DNA?
DOK 1 | B.2.1
Nitrogen
Iron
25. Plant stomata open to release oxygen and close to save water. Level?
DOK 2 | B.1.1
Cellular/Tissue
Atomic
26. Multi-Select: TWO macromolecules forming the cell membrane.
DOK 2 | B.1.4
Lipids (Phospholipids)
Proteins (Channels)
DNA
27. How does the body respond when water is too low?
DOK 2 | B.1.2
Triggering thirst and concentrating urine.
Increasing lipid storage.
28. Which macromolecule is damaged by UV radiation leading to cancer?
DOK 2 | B.2.1
DNA (Nucleic Acid)
Proteins
29. Enzyme action is most efficient at a neutral pH. Which system maintains blood pH?
DOK 2 | B.1.3
Respiratory (by exhaling CO2)
Skeletal
30. Carbohydrates are stored as ________ in the liver for short-term energy.
DOK 1 | B.1.2
Glycogen
Starch
Part V: Case Studies
DNA (nucleic acids) direct the synthesis of insulin (proteins). In Type 1 diabetes, a mutation prevents proper protein formation. Consequently, lipids in cell membranes cannot open channels, and carbohydrates remain in the blood instead of powering mitochondria.
| Marker | Patient | Healthy |
|---|---|---|
| Glucose | 385 mg/dL | 90 mg/dL |
| ATP | Near Zero | Optimal |
31. Explain how failure of insulin production collapses homeostasis using CER.
Claim
Evidence
Reasoning
High blood sugar pulls water from tissues via osmosis. The hypothalamus (Nervous system) detects this stimulus and triggers thirst. The kidneys (Excretory system) use active transport to reabsorb water to maintain blood volume.
Blood Conc.
Set Point
32. Predict effects of water unavailability. Explain system interactions using CER.
Claim
Evidence
Reasoning
Reasoning
In Type 2 diabetes, the signal (insulin) is sent, but the effectors (cells) do not respond. Since glucose channels stay closed, the stimulus (high blood sugar) is never removed. This results in high blood sugar but cellular starvation (low ATP).
The Energy Barrier
Without Enzyme
WITH ENZYME
Homeostasis ensures optimal temperature so these bonds don't break!
04
The lipid bilayer is semi-permeable because its center is hydrophobic (water-fearing).
Cell Transport:
OSMOSIS No Energy
ACTIVE TRANSPORT REQUIRES ATP
OUTSIDE CELL (High Concentration)
PROTEIN CHANNEL
Hydrophobic Interior → Blocks Solutes
1. Control Center: Pancreas detects high glucose.
2. Signal: Pancreas releases INSULIN (Protein).
3. Effector: Cells/Liver absorb glucose & store as GLYCOGEN (Carbohydrate).
RESULT: Blood sugar drops back to set point.
1. Control Center: Pancreas detects low glucose.
2. Signal: Pancreas releases GLUCAGON (Protein).
3. Effector: Liver breaks down GLYCOGEN into glucose.
RESULT: Blood sugar rises back to set point.
DOK 3 Goal
C
"What do you know?"
A concise statement that answers the question directly.
E
"How do you know?"
Citations from the data table or reading passage. Be specific!
R
"Why does it matter?"
Connect the evidence to biological concepts (Standard-based explanation).
Example Connection: "The patient is lethargic (Evidence) because a mutation in DNA (Reasoning) prevents insulin synthesis, meaning cells lack fuel for respiration."
"Homeostasis isn't just about balance; it's about the molecular machinery (Macromolecules) working together as systems."
Good Luck, Biologists!
DOK 2 | B.1.4
PROTEIN CHANNEL
It acts as an absolute barrier that prevents all molecules from entering.
It is semi-permeable, allowing selective entry of solutes to maintain internal conditions.
It attracts nitrogen atoms to build nucleic acids on the surface.
7. DOK 3: Why do metabolic reactions fail during a 106°F fever?
DOK 3 | B.1.2
Membrane lipids melt, causing the cell to dissolve.
Enzyme protein bonds break, causing denaturation and loss of function.
The heart stops to save energy for atomic repair.
Part IV: Advanced Scenarios
8. Insulin acts as a protein signal in a feedback loop. What is its specific role?
DOK 2 | B.1.2
It binds to membrane receptors to trigger glucose channel opening.
It breaks down polysaccharides directly in the blood.
9. Pancreas releases glucagon when blood sugar is low. Response?
DOK 2 | B.1.2
Liver breaks down glycogen to release glucose.
Cells store more glucose as proteins.
10. DOK 3: Why does active transport require ATP whereas osmosis does not?
DOK 3 | B.1.4
It moves molecules against the concentration gradient.
It uses lipids to pull water molecules into the cell.
11. Which system works with the respiratory system to deliver oxygen to muscle tissues?
DOK 2 | B.1.3
Circulatory System
Excretory System
12. Shivering is a response to cold. Which part of the feedback loop is the skeletal muscle?
DOK 2 | B.1.2
Effector
Receptor
13. Lasik surgery corrects vision by reshaping the cornea. Level of organization?
DOK 2 | B.1.1
Tissue level (cornea) within an organ (eye)
Cellular level only
14. A cochlear implant acts as a sensor for sound. Which feedback loop component is it?
DOK 2 | B.1.2
Receptor
Control Center
15. Phosphorus is essential for the backbone of which instructions?
DOK 1 | B.2.1
DNA (Nucleic Acid)
Lipids
16. Immediate energy for respiration comes from which carbohydrate?
DOK 1 | B.2.1
Glucose
Starch
17. Which system interacts with circulatory to remove acidic CO2 waste?
DOK 2 | B.1.3
Respiratory
Digestive
18. Osmosis is the movement of water across which layer?
DOK 1 | B.1.4
Lipid Bilayer
Cell Wall
19. DNA replication is an example of homeostasis at which level?
DOK 2 | B.1.1
Cellular/Organelle
Tissue
20. Which element can form 4 bonds for macro frameworks?
DOK 1 | B.2.1
Carbon
Hydrogen
21. DOK 3: Predict the effect of high fever on DNA instructions.
DOK 3 | B.1.2
DNA remains stable while protein enzymes denature and stop functioning.
DNA turns into simple carbohydrates to provide extra energy.
22. Plant stomata open to release oxygen waste. This is homeostasis at the ________ level.
DOK 2 | B.1.1
Cellular/Tissue
Organism
23. DOK 3: Why is glucose storage in the liver essential for long-term homeostasis?
DOK 3 | B.1.2
It provides a reserve of energy that can be released when blood glucose drops below the set point.
It allows the liver to produce insulin when the pancreas is resting.
24. What is the monomer of a protein enzyme?
DOK 1 | B.2.1
Amino Acid
Nucleotide
25. Multi-Select: Select TWO systems managing blood sugar.
DOK 2 | B.1.3
Endocrine
Digestive
Skeletal
26. Lipids are non-polar. How does this affect their interaction with water?
DOK 2 | B.2.1
They repel water, creating the hydrophobic core of cell membranes.
They dissolve easily in blood plasma.
27. Which system is responsible for filtering excess salts via active transport?
DOK 2 | B.1.3
Excretory
Nervous
28. DOK 3: Why is insulin released after a meal high in starch?
DOK 3 | B.1.2
To signal cells to take in the glucose released from the digested starch.
To increase blood sugar even further to prevent atomic decay.
29. Nitrogen is found in the amine group of which monomer?
DOK 1 | B.2.1
Amino Acid
Fatty Acid
30. Adenosine Triphosphate (ATP) is the molecule of energy. Level of organization?
DOK 1 | B.1.1
Molecular
Organism
Part V: Case Studies
DNA (nucleic acids) direct insulin (proteins) synthesis. In Type 1 diabetes, a mutation prevents proper protein formation. Lipids in membranes cannot open channels, trapping carbohydrates in blood.
31. Explain homeostatic collapse using CER.
Claim
Evidence
Reasoning
High sugar pulls water from tissues via osmosis. Hypothalamus detects this and triggers thirst. Kidneys use active transport to save water.
32. Predict effects and explain interactions using CER.
Claim
Evidence
Reasoning
Reasoning
In Type 2 diabetes, the signal (insulin) is sent, but the effectors (cells) do not respond. Since glucose channels stay closed, the stimulus (high blood sugar) is never removed. This results in high blood sugar but cellular starvation (low ATP).
A
When blood sugar rises (Stimulus), the pancreas (Control Center) produces insulin (Protein). Insulin binds to receptors, opening channels in the lipid membrane. Glucose (Carbohydrate) enters cells for respiration (Energy).
Connect the Failures:
Type 1
Signal (Protein) is not produced.
Type 2
Receptors (Protein) resist the signal.
Result
ATP Starvation & Hyperglycemia.
B
High blood sugar pull water from cells via Osmosis. The Nervous System triggers thirst. The Excretory System reabsorbs water.
Self-Assessment Checklist:
I can identify the STIMULUS (High salt/sugar)
I can identify the CONTROL CENTER (Hypothalamus)
I can identify the EFFECTORS (Kidneys/Behavior)
I can cite EVIDENCE from graphs and data tables.
Prepare to integrate molecular biology with system-level physiology. Focus on "How one level affects the other."
Integration Mastery: Molecular Biology ↔ System-Level Physiology.
