The document discusses homeostasis and how organ systems work together to maintain it. It provides examples of how disrupting homeostasis can damage the body over long periods of time compared to short periods. It also explains how giving insulin to people with type 1 diabetes restores their glucose homeostasis and how living in Alaska could impact calcium and phosphorus levels due to changes in vitamin D exposure between winter and summer. Finally, it discusses potential evolutionary advantages of animals being able to store more glucose in the form of glycogen.

1. +
Formative Assessment
28.3

2. +
1. Why do the organ systems in the
body need to work so closely
together?
 All body systems contribute to maintaining homeostasis. What
happens in one system may require response from another

3. +
2. Explain why a long-term
disruption of homeostasis can often
be more damaging to the body than
a short-term disruption is.
 Long-term disruption can produce a chain reaction in which
more and more organ systems are affected over time. The
result can be permanent damage to organs and possibly death

4. +
3. Why would giving synthetic
insulin to people with Type 1
diabetes restore their glucose
homeostasis?
 Type 1 = no insulin is made. When synthetic insulin is given to
people with Type 1 diabetes, glucose can enter cells, so blood
glucose levels return to normal

5. + 4. If you lived in Alaska for the whole
year, what changes might occur in your
calcium and phosphorus levels during
the winter versus the summer? Explain.
 During winter months:
- Little sunlight & skin fully covered with clothing = very little exposure to UV
light
- Less vitamin D production
- Decrease in calcium and phosphorus levels in the body
 Summer months:
- More exposure of skin to sunlight
- Increase in vitamin D production leads to increased levels of calcium and
phosphorus in the body

6. +
5. Some animals can store more
glucose – in the form of glycogen –
in their bodies than other animals
can. What might be the evolutionary
advantage of having these extra
energy stores?
 Development of more efficient cellular metabolism
 Ability to survive on an irregular food supply
 Ability to mobilize extra glucose rapidly to provide energy in fight-or-
flight situations