Thursday, January 20, 2011

Adaption-Group 1

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

The Mangroves have “peg roots”, also known as pneumatophores. Pneumatophores are poked through the surface of the mud, this allows it to absorb oxygen from the air and transport it into the roots buried in the mud. Mangroves also have excluders. These filters out the salt water which may damage the plant tissues.

2. How are xerophytes adapted to survive prolonged drought?

When a plant is a Xerophyte*, it means that the plant is adapted to low water availability in their environment. Some examples are cactus and cotyledon. They have adapted by having smaller leaves, grow compactly and close to the ground, and a non-porous covering on their leaves such as wax.

*Xerophyte -- Xero means dry while phyte means plant

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

Body temperature, which is normally 37°C (98.6°F), is maintained through a thick layer of fur, a tough hide, and an insulating fat layer (up to 11 cm or 4.5 in. thick). This excellent insulation keeps a polar bear warm even when air temperatures drop to -37°C (-34°F).

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

Female deep-sea anglerfishes have a globular shape, not adapted for sustained rapid swimming, but designed for remaining motionless much of the time.
They have a large mouth and their teeth are huge in comparison of their body. Instead of searching actively for prey, they wave a bio-luminous lure to attract prey. They can cope with very large prey, because they have expandable jaws that can open double wide and they posses an elastic stomach and they eat any kind of prey available. The lures of deep sea anglerfishes are elaborate, made up of sensory filaments, papillae, light pipes and shutters. It may be, that different species mimic different kinds of small prey like shrimps to attract larger prey.  One anglerfish (Linophryne) has a luminous lure on the head and a multi-branched barbel hanging from the lower jay. The barbel filaments of the anglerfish contain more bioluminescent organs so as to attract more prey.


5. Why can’t a seawater fish survive in freshwater aquarium?

The cells of the seawater fish has higher water potential than the freshwater, hence water will enter the cells through osmosis, causing the fish to die.

     What is the difference in pH between seawater and freshwater ponds?
Seawater: 7.5-8.4
Freshwater pond: 6.5 to 7.0

Done By: Michelle, Shawn, Sean, Elgin Low

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