Unit 3 Biology
Homeostasis
Guiding Questions
1. What is homeostasis?
2. When talking about multicellular organisms what do we mean by the “internal environment”?
3. When talking about unicellular organisms what do we mean by the “internal environment”?
4. What are extracellular fluids?
5. What are intracellular fluids?
6. How are extracellular fluids separated from intracellular fluids?
7. What two fluids make up the internal environment of in multicellular organisms?
8. What sorts of nutrients pass from blood to tissue fluid?
9. What sort of waste products pass from tissue fluid to blood?
10. What is the purpose of blood tests?
11. Why is it a concern if extremely high or low levels of a metabolite are detected in a blood test?
12. Describe the relationship between body systems, cells and the internal environment?
13.
14.
15.
16.
When do biochemical reactions occur in cells?
Name some substances that are required in particular amounts in order for cells to function.
What factors influence movement of substances across membranes?
What is the function of enzymes, and what impacts on their functioning?
17. What influences the complexity of homeostatic mechanisms?
18. What do all homeostatic mechanisms require?
19. What are examples of homeostasis in simple unicellular organisms?
20. How do multicellular organisms such as sponges control their internal environment?
21. What sort of physiological mechanisms have evolved to help complex multicellular organisms
maintain homeostasis?
22. Why would organisms conform to their external environment?
23. Why would organisms regulate their internal environment?
24. What type of organisms usually have narrow tolerance levels for changes in the external
environment?
25.
26.
27.
28.
What is the difference between an osmoconformer and an osmoregulatory?
What is the advantage of being an osmoregulator?
What is the disadvantage of being an osmoregulator?
What sets the tolerance of osmoconformers living in a marine environment?
29.
30.
31.
32.
33.
34.
35.
What ability is fundamental to all organisms?
Describe the stimulus response model.
What is the threshold of a receptor?
What two factors can act as stimuli in the maintenance of homeostasis?
What happens when one of these factors change?
Name some examples of internal conditions that can act as stimuli.
Name some examples of external conditions that can act as stimuli.
36. What are misalignment detectors?
37. What are disturbance detectors?
38. What are the four types of receptors?
39. Give an example of each of the four types of receptors?
40. What does homeostasis involve?
41. What controls the size of fluctuations around a set point?
42. What are proportional control systems?
43. What is a negative feedback system?
44. Give an example of a negative feedback system in the body?
45. What is a positive feedback system?
46. Give an example of a positive feedback system in the body?
47. Name the body systems involved in maintaining homeostasis.
48. Why is the circulatory system of particular importance?
49.
50.
51.
52.
What does maintaining homeostasis in relation to glucose require regulation of?
What does maintaining homeostasis in relation to body temperature require regulation of?
What does maintaining homeostasis in relation to water and salt balance require regulation of?
What does maintaining homeostasis in relation to metabolic rate require regulation of?
53. What has research told us about the regulatory systems of newborns?
54. Why do premature babies require particular care?
55. What is the function of the liver?
56. How does it carry out this function?
57.
58.
59.
60.
61.
62.
What two hormones are produced by the pancreas?
What does insulin control?
What does glucagon control?
What cell type makes glucagon?
What cell type makes insulin?
What happens to the levels of insulin and glucagon if blood glucose falls below normal levels?
63. What impact does exercise have on the systems involved in maintaining homeostasis?
64. What impact does pregnancy have on the systems involved in maintaining homeostasis?
65. What impact does living in space have on the systems involved in maintaining homeostasis?