Tuesday, January 18, 2011

Adaptation – Group 3

1. How do mangrove plants such as Avicennia obtain oxygen when their roots are buried in the mud?
  • They have far-reaching exposed roots for structural support in soft soils.
  • Some have pneumataphores, which are above-ground roots filled with spongy tissue and peppered with small holes in order to offer structural support as well as to allow oxygen to be transferred to the roots trapped below ground in the anaerobic (low oxygen) soils.
  • Many of the roots are adapted to stop the intake of a lot of the salt from the water before it reaches the plant.
Source(s): http://indigiscapes.redland.qld.gov.au/Plants/Mangroves/Pages/Adaption.aspx

2. How are xerophytes adapted to survive prolonged drought? 

  • They store water in their stems or leaves
  • They have no leaves or small seasonal leaves that only grow after it rains
  • They have long root systems spread out wide or go deep into the ground to absorb water
  • They have a short life cycles.
  • They have leaves with hair help shade the plant, reducing water loss.
  • They have spines to discourage animals from eating plants for water.
  • They have waxy coating on stems and leaves help reduce water loss.
  • They have flowers that open at night lure pollinators who are more likely to be active during the cooler night.
  • 9. They grow slower and therefore requires less energy.  The plants don't have to make as much food and therefore do not lose as much water. 
Source(s): http://www.mbgnet.net/bioplants/desert.html

3. How do polar bears survive in regions where temperatures are constantly freezing? 
  • A polar bear has black skin, which absorbs and holds heat from the sunlight.
  • The dense fur on its feet allows for warmth and traction.
  • It has two layers of fur to help insulate itself.
  • It has compact ears and a small tail to prevent heat loss.
  • Insulating blubber not only helps polar bears stay afloat, it also helps them keep heat in.
Source(s): http://www.articlesbase.com/environment-articles/polar-bears-adaptation-to-the-cold-and-unforgiving-arctic-climate-371036.htmlhttp://www.suite101.com/content/polar-bears-adaptations-to-the-freezing-arctic-a189323

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

The deep sea anglerfish live about 3,000 feet under the sea, a place where little light can enter. It 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. When the anglerfish is hunting, it waves this elongated dorsal spine back and forth to attract prey. 

Source(s): http://www.seasky.org/deep-sea/anglerfish.html

5(a). Why can't saltwater fish survive in freshwater aquarium? 
  • Saltwater fishes have cells that contain salt.
  • When placed in fresh water, cells will absorb water through osmosis.
  • The cells will swell up and rupture.

5(b). What are the differences in pH between seawater and freshwater ponds? 

  • Saltwater ponds are more stable than freshwater.
  • Saltwater ponds are less subjected to change than freshwater ponds.
  • pH in seawater is slightly more alkaline than freshwater.
  • pH in freshwater is more subjected to changes due to the weather
Source(s): http://docs.google.com/viewer?a=v&q=cache:2Mf-ASFelw0J:sps.nus.edu.sg/~leewanje/phsyio.ppt+saltwater+fish+difference+freshwater+-site:.com&hl=en&pid=bl&srcid=ADGEESiDf7vbxscb1ZSCnrv8hFEmeJ3vztBIX14KWclwyzoqQETxPf7c3RS6HgugDJ-xalYj58sbT3ywiiuiYm9My1WCJMapwBrz2yVLM7ozBhrOmd_OKxDyLNR94Zv0xZ0lIELDZ4vZ&sig=AHIEtbSI6BvO1JQb_UY961asWVsjkXhjwg&pli=1

Done by: Lim Hao Yang, Sun Jie Min, Neo Wei Hong, Wong Jing Yi

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