Sunday, January 16, 2011

Biodiversity 5 - An Organism's World (Abiotic factors in an environment)

Group work:
Conduct online research to find the out how organisms live in different environment with different abiotic factors.

1.             How do mangrove plants such as Avicennia obtain oxygen when their roots are buried in the mud?
2.             How are xerophytes adapted to survive prolonged drought?
3.             What do polar bears survive in regions where temperatures are constantly freezing?
4.             How do deep-sea anglerfish locate its prey in darkness?
5.             Why can’t a saltwater fish survive in freshwater aquarium? What are the differences in pH between seawater and freshwater ponds?

- Post your findings in the class Environmental Science blog.
- Include pictures to elaborate or support your findings.
- Students are to review each group findings.

What is the key understanding of this lesson?


  1. 1)They have pores in their bark through which they absorb oxygen.

    2)Xerophytes are plants which are able to survive prolonged drought. They reduce their transpiration to conserve water. They also store water in swollen stems.

    3)polar bears have thick fur to trap heat from escaping and thick skin to reduce heat loss to survive in the cold area.

    4)Angelfish have a rod-like antenna with a light a the end. The fish will swim towards the light, curious and than get eaten.

    5)They are adapted to salt water conditions. There are minerals in salt water that many of these fish need in order to survive so they will die in fresh water.

  2. Adam Tan, Tay Kun Yao, Kieren Chua1/18/2011 12:26:00 PM

    1) The mangrove plants developed their roots exposed to the air. Organism such as mud crabs burrow tunnels and enable oxygen circulation throughout the soil.
    2) A xerophyte is an organism is a plant which can survive in area with little water or moisture like a desert.Some adaptations help the plant to limit water loss,minimize loss of water and also store water for a long period of time.Some examples of adaptations are needle-like leaves and waxy stomata.For the storage of water some plants have fleshy tuber which contain a lot of water and also have a deep root system to collect the water underground.
    3) Polar bears are insulated by two layers of fur that help keep them warm. Their compact ears and small tail also prevent heat loss. In fact, polar bears have more problems with overheating than they do from the cold—especially when they run.
    4) The angler uses 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.
    5) If you put a freshwater fish into saltwater, most fish would lose weight (from losing or absorbing water from/into its body) and eventually die. Although there are some kinds of fishes that can survive in both saltwater and freshwater, the change in salinity has to be gradual so that the fish can adapt to the environment.Seawater pH is limited to the range 7.5 to 8.4 and freshwater pH is 6.0 to 8.0pH.

  3. 1) The struggle for oxygen: 
The mangrove tree Avicennia marina which is characterized by having root outgrowths from the ground called pneumatophores. They look like small tubes sticking out of the ground.

    they survive because the have long roots that go down in search of water, they don't get hot because they don't have big leaves, also thier insides are full of water storage!

    Cactuses have very long roots that go deep into the deserts dry ground to search for water and animals don't try to dig them up as their water inside them contains a poisson and they have spines instead of leaves which reduces the surface area to not lose valuable water!

    Read more:

    plant adapted for life with a limited supply of water

    3)What do polar bears survive in regions where temperatures are constantly freezing?

    Polar bears keep warm quite easily actually, they have a very thick layer of blubber under their furry, warm fur. The blubber keeps them insulated and the fur keeps them cozy and warm. Also sometimes, to get out of the harsh Arctic wind, the bears burrow deep under layers of snow.

    Read more:

    5)It basically uses its lure, which emits light to attract its prey. While remaining motionless, it waves its lure back and forth, and waits for the prey to come closer to its mouth. The specialized spine attached to the lure can also be moved by the fish in any direction. Moreover, the 'esca' is connected with the mouth reflex, so that when the prey touches it, the anglerfish can instantly snap the prey with the powerful jaw and then swallow it

    6)saltwater fish have evolved to be constantly drinking water and excreting salts. When you put a saltwater fish into freshwater, it continues to drink heavily and excreet salt. Thus the fish quickly loses too much salt, and its body begins to react accordingly

    Read more:'t_salt_water_fish_live_in_fresh_water#ixzz1BMFvLZc1

    Ph value of freshwater is 7 while the ph value for salt water abve 7

  4. Abigail, Daniel and Mohit :D

    1. The structure of the rooting system helps trapping sediment carried in the incoming currents and high tides. The plants have physically developed their roots exposed to the air.

    2. Xerophytes have a waxy stomata,large hairs on surface and curled leaves to limit water loss. They increase the amount of water with a root system that spreads across a large area. They also store water in their thick fleshy stems like the cactus.

    3. Polar bears have transparent fur over black skin. The reflection of the sunlight from the densely packed transparent hairs makes polar bears seem to white. The black skin absorbs heat from the sunlight. The hollow hairs are called guard hairs.

    4. Deep-sea anglerfish has this extension from the head which produces light.The deep sea anglerfish uses this light to both locate and attract its prey.

    The polar bears have a thick layer of bubbler which can insulating fat. The fur is also waterproof, it helps to keep the bear warmer when they are in the water.

    5. If the salt water fish were to be put in fresh water then their high salt content inside their bodies, will have it diffusing out down the concentration gradient which will kill them. If the fresh water fish were to be put in salt water then their low salt content inside their bodies will have it diffusing in again down the concentration gradient which will kill them.

    The pH value of sea water is 8 while the pH value of freshwater is 6.5 and 8.0.