Definitions

Question 1

Homeostasis

Answer 1

The ability to adjust its internal environment to maintain a stable equilibrium despite the external environment

Question 2

Osmoregulation

Answer 2

The ability to regulate salt and water balance within intra- and extra-cellular fluids to achieve optimal conditions

Question 3

Osmosis

Answer 3

When solvents (typically water) pass though a semi-permeable membrane from less to more concentrated solution

Question 4

Osmolarity

Answer 4

Ratio of solutes to water

Question 5

Osmoconformer

Answer 5

Matchs body’s osmolarity with external environment (Iso-osmotic to their environment). Little energy needed.

Example : Invertebrates and some sharks

Question 6

Osmoregulator

Answer 6

Regulates body’s osmolarity to maintain a constant internal environment even if the external environment is different. Lots of energy needed as there is lots of active transport.

Question 7

Ammoniotelic Animals

Answer 7

Excrete nitrogen as NH3. NH3 is poisonous and is drawn out into external environment as it is pulled by water (NH3 + H = NH4).

Question 8

Ureotelic Animals

Answer 8

Excrete nitrogen as urea. This requires water and energy to excrete.

Question 9

Uriotelic animals

Answer 9

Excrete nitrogen as uric acid. Uric acid is harmless but requires low solubility and low water to be excreted.

Question 10

The Donnan Equilibrium

Answer 10

When large charged particles (proteins) cannot pass through the semipermeable membrane but their charge still contributes to cell potential; Ion concentrations in the cell change to account for the proteins.

Question 11

Stenohaline

Answer 11

able to tolerate only a narrow range of salinity

Question 12

Euryhaline

Answer 12

able to tolerate a large range of salinity