Chapter 3
Animal Physiology: From Genes to Organisms · 5 exercises
Problem 1
What advantages are there to using diffusion as a transport mechanism versus active transport of a substance?
6 step solution
Problem 2
A trout exposed to acid mine drainage experiences an increase in mucus production along the gills. According to Fick's law of diffusion, how would that affect the movement of oxygen through the gill capillaries?
4 step solution
Problem 3
Why would hyponatremia (low plasma sodium concentrations) in an animal be better treated with an \(\mathrm{Na}^{+}\)/ glucose solution rather than the ingestion of salt tablets alone? Normal plasma sodium concentrations are between 135 and \(145 \mathrm{mEq} / \mathrm{L}\), while severe diarrhea or vomiting can lower concentrations to less than \(125 \mathrm{mEq} / \mathrm{L}\).
5 step solution
Problem 6
How is primary active transport different from that of secondary active transport? Which form of transport does the \(\mathrm{Na}^{+} / \mathrm{K}^{+}\)pump use? Explain.
4 step solution
Problem 8
Consider the effect of a twofold increase in the ECF concentration of \(\mathrm{Na}^{+}\)or \(\mathrm{K}^{+}\)ions. Which increase in ion concentration is the more deadly and why? Hint: Consider if the calculated decrease in \(E_{K}+\) or the increase in \(E_{\mathrm{Na}}+\) bring the resting membrane potential of the nerve or muscle cell closer to threshold potential? Why would this change in ion concentration stop the heart from beating?
7 step solution