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?

5 comments:

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

    Mangrove plants develop air breathing roots that stick out of the mud to get air. These roots have on their surface, special tiny pores to take in air, called lenticels. Only air can get through the lenticels, not water or salts. These roots also contain large air spaces . These not only transport air, but also provide a reservoir of air during high tide when all the aerial roots may be underwater.

    How are xerophytes adapted to survive prolonged drought?

    Xerophytes meaning Dry Plant (Xero - Dry, Phyte - Plant). Adaptations found are 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, and succulence, or storage of water in swollen stems, leaves or root tissues.

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

    Polar bears maintain their body heat even when air temperatures drop to -37°C(-34°F). This 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).

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

    Using one of their detached and modified spines of their anterior dorsal fins, it illuminates and wiggle about to act as a prey so as to lure their bait. The spine is movable in all directions. Once close enough, it is able to devour their prey whole. The jaws are triggered in automatic reflex by contact with the tentacle.

    Some bottom-dwelling forms have arm-like pectoral fins which the fish use to walk along the ocean floor. The pectoral and ventral fins are so articulated as to perform the functions of feet, enabling the fish to move, or rather to walk, on the bottom of the sea, where it generally hides itself in the sand or amongst seaweed. All around its head and also along the body, the skin bears fringed appendages resembling short fronds of seaweed, a structure which, combined with the extraordinary faculty of assimilating the colour of the body to its surroundings, camouflage the fish in areas abundant with prey.

    Why can’t a saltwater fish survive in freshwater aquarium? What are the

    differences in pH between seawater and freshwater ponds?

    A saltwater fish drinks salt water. It constantly pumps out excess salt from its body. If it is put in fresh water, it will keep drinking and pumping the salt out, losing too much salt, killing it. The high salt content in the saltwater fish’s body causes its water to diffuse out of the body when it is placed in fresh water.

    ReplyDelete
  2. This comment has been removed by the author.

    ReplyDelete
  3. Qn1: To avoid suffocation in the oxygen poor (anaerobic) mud, they have pencil-like pneumatophores. These stick out at regular intervals from long shallow underground cable roots.

    Source:http://www.naturia.per.sg/buloh/plants/avicennia.htm

    Qn2: A xerophyte is a plant who needs little water. They usually have:
    waxy stomata
    few stomata
    succulent leaves
    succulent Plant stem
    large hairs
    And example is a prickly pear

    Source: http://en.wikipedia.org/wiki/Xerophyte

    Qn3: Polar Bear is a warm-blooded vertebrate, and has to keep warm to maintain the body at a constant temperature. They have
    -very thick fur, that insulates the body by trapping air.
    -a layer of stored fat under the skin to provide more insulation
    -white fur made of hollow hairs, to trap and warm air
    -Oily and water repellent fur, so they can easily get water off their fur after swimming

    Source: http://www.kidzone.ws/sg/polarbear/polar_bear.htm , http://www.ypte.org.uk/environmental/wildlife-in-winter-adaptations-for-survival/112

    Qn4: The deep sea angler fish has a long fishing-rod-like adaptation protruding from its face and on the end of it which is a bioluminescent piece of skin that wriggles like a worm to lure its prey .

    Sources: http://www.seasky.org/deep-sea/anglerfish.html

    Qn5: 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. Salmon are an exception, they thrive both in sea and fresh water. There are many other exceptions as well, since a lot of fish live in coastal and delta and even river to sea waters.

    Source:http://www.answerbag.com/q_view/22724

    pH level 7.5 to 8.4 Saltwater

    Ph level 5.5 to 7.5 Freshwater

    ReplyDelete
  4. 1. Mangrove roots not only provide support in unstable soils and to withstand currents and storms, but also breathe air. To avoid suffocation in the oxygen poor mud, mangrove trees snorkel for air. They develop aerial or air-breathing roots. These take in aboveground air. All aerial tree roots have on their surface, special tiny pores to take in air (lenticels). Only air can get through the lenticels, not water or salts. All aerial roots also contain large air spaces (aerenchyma). These not only transport air, but also provide a reservoir of air during high tide when all the aerial roots may be underwater. The function of aerial roots are to absorb air or/and to provide structural support in the soft mud. Roots for absorbing nutrients are tiny and emerge near the muddy surface.

    2. Most xerophytes have long roots to help them reach water sources far beneath the earth that is protected from the heat.
    Most xerophytes also have small needle like leaves which are known as ‘spines’, they have these really small leaves to reduce the amount of water loss from the leaves due to the desert heat, the main body of most xerophytes are also optimal to store the maximum amount of water as water is usually scarce.

    3. Their hairs act like fibre glass cables and transport the ultraviolet (UV) light of the sun directly to the animal's black skin, where it is converted into useful heat. Polar bears also have blubbers (which is a thick layer of fats) to keep them warm.

    4. The Anglerfish has an elongated dorsal spine that protrudes from the Anglerfish’s head. It supports a light-producing organ known as a photophore. The photophore produces a blue-green light through a chemical process. The Anglerfish uses this to lure their prey in the dark.

    5. All living organisms have to maintain a certain level of a substance in order to survive.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. 


    Azeem, Bernard, Javin, Casandra and Khim

    ReplyDelete
  5. Qn1: Mangrove roots do not only provide support in unstable soils and to withstand currents and storms, it also breathe air. To avoid suffocation in the low oxygenated mud, mangrove trees snorkel for air. They grew air-breathing roots that breathes out of the mud. All aerial roots also contain large air spaces. These not only transport air, but also provide a reservoir of air during high tide when all the aerial roots may be underwater. The function of aerial roots are to absorb air or/and to provide structural support in the soft mud. There are also roots for absorbing nutrients, they are tiny and emerge near the muddy surface.
    Source:
    Qn2: Xerophytes have a waxy coating, spines instead of leaves and tightly closed stomata to reduce water loss. It also stores water in the stem.
    Source: www.rivenrock.com/adaptation.htm

    Qn3: Polar bears have a 10 cm layer of blubber under their skins and have fur which grows up to 2.5 to 5 cm thick consisting of a layer of dense underfur and an outer layer of guard hairs which help to maintain heat by trapping their body heat. The polar bear’s fur is also oily and water repellent preventing the hairs from matting. This allows the polar bears to shake free of water and any ice from their fur that may form after swimming for extended periods of time.
    Source: http://www.seaworld.org/infobooks/PolarBears/pbphysical.html
    www.wikipedia.org

    Qn4: It has a light-producing organ known as a photophore. Through a chemical process and with the help of million of bioluminescent bacteria, 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.
    Source:
    http://animals.nationalgeographic.com/animals/fish/anglerfish.html
    http://www.seasky.org/deep-sea/anglerfish.html

    Qn5: The cells in a saltwater fish put in freshwater would quickly absorb water from the environment, and with no way to eliminate it as they are not made to excrete water, the cells would swell, burst, become waterlogged and kill the fish.

    http://www.ehow.com/facts_6196975_freshwater-saltwater-fish.html
    http://www.ehow.com/facts_7176329_can-fish-live-opposite-environments_.html

    Saltwater contains far greater concentrations of salt than freshwater. Saltwater environments also have higher pH levels (typically 8.3) than freshwater environments (typically around 7.0). Each environment has its own unique organisms adapted for it.

    http://www.ehow.com/facts_7176329_can-fish-live-opposite-environments_.html

    ReplyDelete