Tuesday, January 18, 2011

Group 1

Wu Shen, Jonathan and Mirza

1. How do mangrove plants such as Avicennia obtain oxygen when their roots are buried in the mud?

Avicennia, obtain oxygen by its root which sticks out of the ground. Not only that, Avicennia also has pneumatophores which allows its roots to breathe even when submerged.

2. How are xerophytes adapted to survive prolonged drought?

Xerophytes have reduced permeability of the epidermal layer, stomata and cuticle to maintain optimal amounts of water in the tissues by reducing transpiration, adaptations of the root system to acquire water from deep underground sources or directly from humid atmospheres (as in epiphytic orchids), and succulence, or storage of water in swollen stems, leaves or root tissues. - Wikipedia

3. How do polar bears survive in regions where temperatures are constantly freezing?

Polar bears are insulated by 10cm of thick blubber. They are nearly invisible under infrared photography.

4. How do deep-sea anglerfish locate its prey in darkness?

The anglerfish has an elongated dorsal spine that supports a light-producing organ also known as a photophore. Through a chemical process known as bioluminescence, this photophore can produce a blue-green light similar to that of a firefly on land. With this light, the anglerfish could see in the deep, dark sea.

5. Why can’t a saltwater fish survive in freshwater aquarium? What are the differences in pH between seawater and freshwater ponds?

Freshwater. Water with dissolved salt content measuring less than 1% is called Freshwater. Freshwater is available from two types of sources, stagnant water bodies, such as, Lakes, Ponds, & Inland Wetlands; and flowing water bodies, such as, Rivers and Streams. Freshwater covers only 1% of the total earth’s surface.

Saltwater. When water has high quantity of salts dissolved in it, it is called Saltwater. Owing to the large amount of dissolved salts and the associated electric charges on these salts, the conductivity of saltwater is high and it tastes salty. Sea, Oceans, Rivers, and Saltwater Ponds are the natural sources of saltwater, which add up together to cover 71% of earth surface.

If the salt water fish were to be put in fresh water then their high salt content inside their bodies (to prevent too much salt diffusing into their bodies) will have it diffusing out down the concentration gradient; killing them. If the fresh water fish were to be put in salt water then their low salt content inside their bodies (to prevent too much salt diffusing out of their bodies) will have it diffusing in again down the concentration gradient; killing them.

They are adapted to salt water conditions. There are many other minerals in salt water besides salt many species of fish need those other minerals in order to survive thus they die in fresh water.

No comments:

Post a Comment