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9700 A Level Biology/Topic 14 Homeostasis/9 interactive simulations/drag to rotate the 3D models

Homeostasis, made interactive

Nine 3D simulations covering Topic 14.1 Homeostasis in mammals and 14.2 Homeostasis in plants. Follow a feedback loop, explore the kidney and nephron, filter blood, release ADH, amplify a glucagon signal, balance blood glucose, test for glucose and open and close stomata.

1. Principles of homeostasis 3D · 14.1

Homeostasis keeps the internal environment near a set point using receptors, coordination systems, effectors and negative feedback. Disturb core temperature and follow the loop.

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Stimulus

2. The kidney 3D · 14.1

The kidneys remove urea, made in the liver by deamination of excess amino acids, and regulate the water potential of the blood. Click the parts of the cut kidney.

click a part · drag to rotate · wheel to zoom

Structure

3. The nephron 3D · 14.1

Each kidney has about a million nephrons. Click the parts of a nephron and its blood vessels.

click a part · drag to rotate · wheel to zoom

Part

4. Ultrafiltration and selective reabsorption 3D · 14.1

The structure of the Bowman's capsule and the proximal convoluted tubule suits their jobs. Watch which substances pass through.

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Process

5. Osmoregulation and ADH 3D · 14.1

Osmoreceptors in the hypothalamus detect the water potential of the blood. ADH from the posterior pituitary gland makes the collecting duct more permeable to water.

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Blood water potential

ADH
URINE

6. Cell signalling: glucagon and cAMP 3D · 14.1

One glucagon molecule binding to a liver cell triggers a cascade that releases thousands of glucose molecules. Step through it and watch the amplification.

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Step

STEP
ACTIVE MOLECULES

7. Insulin and glucagon 3D · 14.1

Negative feedback keeps blood glucose near 5 mmol dm⁻³. See what insulin does to muscle and liver cells, and what glucagon does to liver cells.

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Event

8. Test strips and biosensors 3D · 14.1

Glucose oxidase and peroxidase let us measure glucose in urine or blood. Set the glucose concentration and test it.

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Sample

READING
-

9. Control of stomata 3D · 14.2

Guard cells open and close stomata, balancing carbon dioxide uptake against water loss. Switch between day, night and drought.

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Conditions

Built for Cambridge AS & A Level Biology 9700, Topic 14 (A Level). Models are simplified and not to scale; values are illustrative.

About this lab: Homeostasis

Nine interactive 3D simulations for Cambridge A Level Biology 9700 topic 14 Homeostasis: the principles of homeostasis and negative feedback, the structure of the kidney, the nephron and its blood vessels, ultrafiltration in the Bowman's capsule and selective reabsorption in the proximal convoluted tubule, osmoregulation by the hypothalamus, posterior pituitary, ADH and aquaporins, cell signalling by glucagon through G proteins, cAMP and an enzyme cascade, the actions of insulin and glucagon, glucose test strips and biosensors, and the opening and closing of stomata with abscisic acid.

Nine 3D simulations covering Topic 14.1 Homeostasis in mammals and 14.2 Homeostasis in plants. Follow a feedback loop, explore the kidney and nephron, filter blood, release ADH, amplify a glucagon signal, balance blood glucose, test for glucose and open and close stomata.

Homeostasis is a free, browser-based simulation for Cambridge International AS & A Level Biology 9700 (topic 14 Homeostasis). The course is assessed in Paper 1 (Multiple choice), Paper 2 (AS structured), Paper 3 (Advanced practical), Paper 4 (A Level structured), Paper 5 (Planning, analysis, evaluation). Syllabus for examination in 2025-2027. There are 9 tabs, each a self-contained experiment with its own controls and live readings, and nothing to install: it runs on a laptop, tablet or classroom projector.

Syllabus coverage

Full syllabus map: A Level Biology 9700 topic 14.

How to use this simulation

  1. 1. Principles of homeostasis. Homeostasis keeps the internal environment near a set point using receptors, coordination systems, effectors and...
  2. 2. The kidney. The kidneys remove urea, made in the liver by deamination of excess amino acids, and regulate the water potential of...
  3. 3. The nephron. Each kidney has about a million nephrons.
  4. 4. Ultrafiltration and selective reabsorption. The structure of the Bowman's capsule and the proximal convoluted tubule suits their jobs.
  5. 5. Osmoregulation and ADH. Osmoreceptors in the hypothalamus detect the water potential of the blood.
  6. 6. Cell signalling: glucagon and cAMP. One glucagon molecule binding to a liver cell triggers a cascade that releases thousands of glucose molecules.
  7. 7. Insulin and glucagon. Negative feedback keeps blood glucose near 5 mmol dm⁻³.
  8. 8. Test strips and biosensors. Glucose oxidase and peroxidase let us measure glucose in urine or blood.
  9. 9. Control of stomata. Guard cells open and close stomata, balancing carbon dioxide uptake against water loss.
  10. The buttons at the end of the tab strip give the scene the whole window (Full screen, Hide controls) and, on a dark stage, a projector-friendly palette (Light scene). Many scenes also have drag handles: drag them to change the set-up directly.

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