1. Fresh water would be hypotonic to the fish's body fluids. Its cells would osmotically gain water and burst, soon killing the fish. If a freshwater fish were placed in a marine aquarium, its cells would lose water and shrivel, like crenated blood cells, and it would also die.

2. The sodium-potassium pump maintains a high intracellular and low extracellular concentration of potassium ions. Crush injuries tend to release large amounts of K⁺ from the cells and raise the K⁺ concentration of the blood plasma.

3. Low levels of blood albumin reduce the osmotic pressure of the blood, so the blood stream cannot retain water as well. Water diffuses into the tissues and body cavities, more water is excreted in the urine, and blood volume and pressure drop.

4. Mitochondria cannot make energy (recall the law of conservation of energy and mass); they only transfer it from one molecule to another. All the energy needed by a cell is made by the sun, trapped by photosynthetic organisms, and passed on from organism to organism on earth.

5. Without dynein, cilia and flagella are immobile. For lack of sperm motility, a man with Kartagener syndrome is sterile. For lack of ciliary motility, he also has severe respiratory congestion, since the cilia are unable to expel mucus from the respiratory tract.

Copyright ©1998 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use and Privacy Policy.
McGraw-Hill Higher Education is one of the many fine businesses of The McGraw-Hill Companies.
For further information about this site contact mhhe_webmaster@mcgraw-hill.com.