Wednesday, January 19, 2011

Adaptation-Group 4

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

-Avicennia has "roots" which outgrowths from the ground called pneumatophores. It helps to obtain oxygen as they have loosely packed tissues to allow effective diffusion of gases into the pith.

-It also develops shallow cable roots which spread out from the trunk, where along these cable roots, it emerge short pencil-like roots, pneumatophores.


2) How are xerophytes adapted to survive prolonged drought?

-Xerophytes often have few or no leaves, which reduces transpiration.

-Xerophytes are the most drought-resistant plants on the planet as they do not have leaves, they have a shallow root systems, they have ability to store water in their stems, spines for shade and waxy skin to seal in moisture.


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

-They have a thick coat of insulated fur, which covers a warming layer of fat.
-They have black skin which can soak in the sun's warming rays better.
-Their stark white coat provides camouflage in surrounding snow and ice.
-They are insulated by two layers of fur that help keep them warm.
-Their compact ears and small tail also prevent heat loss.


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

• The Anglerfish, female in particular, has an elongated dorsal spine that supports a light- producing organ 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.
• The fish uses this appendage like a fishing lure, waving it back and forth to attract its prey.
• Their mouths are so big and their bodies so pliable, they can actually swallow prey up to twice their own size.

The male, which is significantly smaller than the female, has no need for such an adaptation.

• The male has evolved into a permanent parasitic mate. When a young, free-swimming male angler encounters a female, he latches onto her with his sharp teeth.
• Over time, the male physically fuses with the female, connecting to her skin and bloodstream and losing his eyes and all his internal organs except the testes. A female will carry six or more males on her body.


5a. Why can't a saltwater fish survive in freshwater aquarium?

-Salt water fish tanks are considered more difficult to keep than freshwater tanks because salt water fish have less tolerance for fluctuations that can occur quickly within the closed environment of an aquarium.

5b. What are the difference in pH between seawater and freshwater ponds?

-The pH of a saltwater aquarium must stay between 8.2 and 8.4, according to, while pH levels in a freshwater aquarium can range from 6.0 to 9.0.


Done by: Jun Peng, Michelle Lim, Kristin and Clarabelle

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