Osmoregulation and Excretion
1. Why must organisms thermoregulate?
some mechanisms by which
gain or loose heat.
3. Compare and
and endotherms with respect to:
- General mechanisms of regulating body temperature.
- Relationship between body temperature and ambient temperature.
4. What is torpor?
different states of torpor (hibernation, estivation) and
their adaptive significance.
5. Why must
organisms regulate their
6. Why can
most aquatic animals excrete
wastes as ammonia? Why do most terrestrial animals
nitrogenous wastes as urea or
uric acid? What
are the advantages of excreting uric acid for animals like birds and
7. Why must
Describe the differences between hyperosmotic,
and isoosmotic solutions. Define osmolarity.
8. Compare and
- What osmotic problems do organisms that live in freshwater
What osmotic problems do marine organisms face? Describe some
that have evolved to solve these osmotic problems.
9. What is the
main osmotic problem that
10. Describe the
three general processes common
to animal excretory systems.
11. Compare and
contrast the excretory systems
invertebrates and vertebrates.
12. Describe the
anatomy of the mammalian kidney.
Your discussion should include the following terms renal artery,
vein, ureter, renal cortex, renal medulla, and renal pelvis.
13. Trace the
pathway of a molecule of urea from
the time it enters the nephron until it is excreted into the
pelvis. As you do this consider the following:
- the process of filtration in the glomerulus and Bowman’s
- the process of secretion and reabsorption in the proximal
tubule and distal tubules.
- the reabsorptive processes that occur in the Loop of Henle
- how the pathway of amino acids or sugar might differ from that of
14. How are cortical
nephrons? Describe how juxtamedullary nephrons allow mammals
to generally excrete hyperosmotic urine. Why is this adaptive?
15. When might it be
beneficial to excrete
urine? What other organ systems participate in regulating urine
16. Describe some of
the diverse adaptations
have evolved in the vertebrate kidney.