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Thursday, February 24

Saturday, November 20

  1. page Chordata-Aves edited Chordata- {free_unique_birds_screensaver-66791-3.jpg} Chordata- Aves By: Yarden Avnor {webk…

    Chordata-{free_unique_birds_screensaver-66791-3.jpg} Chordata- Aves
    By: Yarden Avnor
    {webkit-fake-url://0B676536-C731-4B64-A58D-071386313B2F/Aves_Allure__Western_Australia_copy.jpg} Aves_Allure__Western_Australia_copy.jpgLJ
    ...
    A huge focus of birds is to protect their young from predators. Even their tricks such as the broken wing are to defend their young. Their most impressive mechanism is how they hide their nest. A bird tries to keep the nest hidden from predators by blending it in with the surroundings. This is similar to mimicry because it is appearing like something else. The African Palm-Swift uses its saliva as glue to hold its nest in place. Some birds intentionally build their nests next to an organism that does not prey on them, but preys on their predators. This keeps them from being eaten or attacked. An example of this is in the Siberian Tundra, where the red-breasted goose and the falcon nest at the same time. The goose is kept safe from the fox by the falcon. (NG)
    Fight is one of the most prominent tactics for aves to protect themselves. However, some aves are flightless. In these cases their size has enabled them to escape predation. For example, ostriches can weigh from 140- 290 pounds and height of 5- 9 feet and may not be able to fly, but they have survived many years. Why is that? Their wings may be small but they help to balance the birds while running, turning, and swerving. An ostrich acting in self-defense will extend first one wing and then the other in repeated, threatening motions resembling those of a boxer. In a charge, ostriches fully extend their wings, creating an awesome spectacle. Ostriches and emus are strong, fast runners. They can run up to 4O miles an hour, emus covering 9 feet, ostriches 25 feet in a stride. Their toes--emus and other flightless fowl have three and ostriches have two, compared to the four toes of flying birds--are made for speed, as fewer toes mean less ground contact, adding more speed. The long, powerful legs of these birds are their main weapon of defense, enabling them to flee or fight. Ratites fight with kicks, kicking from the knees (technically the ankles) forward and down, instead of backward. (7,8)(ZS)
    ...
    new coat every
    every
    year. The
    Birds have claws or nails to enhance self-protection. They cover the toes and fingers, are usually curved in shape, and are often sharply pointed. Birds use these claws for grabbing potential food off the ground, and can also use them for self-protection. (CC) (13)
    Osmotic and temperature balance
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    5:07 pm
  2. page Chordata-Aves edited ... The Diagnostic Characteristics The Chordata--Aves, which are apart of the Animalia kingdom, a…
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    The Diagnostic Characteristics
    The Chordata--Aves, which are apart of the Animalia kingdom, are commonly known as birds. This specific taxa has several prominent traits that distinguish and separate it from the other taxa. Birds all have the unique characteristic of feathers which are made out of Keratin( a substance that seemed to be quite adaptable during the avian evolution). It is the shape and arrangement of the feathers that makes it possible for the bird to fly since they make the wing an airfoil. The honeycombed bone structure of the birds which is strong and light, also allows for successful flight.
    ...
    all have
    toothless
    toothless mandibles which
    ...
    system below).
    Another

    (KS)Another
    characteristic in
    ...
    parental investment. (KS)
    Acquiring and digesting food /metabolic waste removal
    As birds acquire food such as seeds with their beaks, the food enters their mouth but is not chewed because only bills are present. Next, the food enters the esophagus, crop, stomach, gizzard, intestine, and finally out the anus in one direction which therefore allows for the presence of specialized regions and organs to carry out digestion in an orderly and sequential manner. The complete digestive tracts and alimentary canals are considered to be the digestive tubes within the birds that extends between the mouth and anus. The crop, stomach and gizzard are the three separate chambers where acquired food is pulverized and churned before entering the intestine, where chemical digestion and the absorption of nutrients occurs. It must be noted though that some Aves are missing some of these digestive organs. This type of Extracellular digestion, which breaks down food outside the cells, is the main pathway the body receives its nutrients from the food it obtains
    ...
    Fight is one of the most prominent tactics for aves to protect themselves. However, some aves are flightless. In these cases their size has enabled them to escape predation. For example, ostriches can weigh from 140- 290 pounds and height of 5- 9 feet and may not be able to fly, but they have survived many years. Why is that? Their wings may be small but they help to balance the birds while running, turning, and swerving. An ostrich acting in self-defense will extend first one wing and then the other in repeated, threatening motions resembling those of a boxer. In a charge, ostriches fully extend their wings, creating an awesome spectacle. Ostriches and emus are strong, fast runners. They can run up to 4O miles an hour, emus covering 9 feet, ostriches 25 feet in a stride. Their toes--emus and other flightless fowl have three and ostriches have two, compared to the four toes of flying birds--are made for speed, as fewer toes mean less ground contact, adding more speed. The long, powerful legs of these birds are their main weapon of defense, enabling them to flee or fight. Ratites fight with kicks, kicking from the knees (technically the ankles) forward and down, instead of backward. (7,8)(ZS)
    Feathers are an important protection mechanism for birds. Birds are able to grow feathers easily and some birds can produce a new coat every year. The coloration of a bird’s feathers provides camouflage as well as a way to communicate with mates and rivals. These feathers are both lightweight and strong which make flying easier for a bird. This allows them to get allow from predators. In addition, a bird’s feathers act as insulations that help the birds stay warm. Also, the feathers are used for physical protection for the bird’s body. (9)(MF)
    ...
    self-protection. (CC) (13(13)
    Osmotic and temperature balance
    Aves maintain a body osmotic pressure that is different than their environment, which is known as homeostasis.
    ...
    A chick embryo, magnified six times with a microscope. (NI) 14
    Male ducks fight for dominance during mating season. (MC)
    Review Questions__Questions
    1. Describe the anatomical characteristics that enable species of aves to fly. Why can’t all species of birds fly? (MT)
    2. How many chambers do Aves have in their hearts and why is this beneficial aerodynamically? (RG)
    ...
    Sources:
    Main source: Campbell, N.C., Reece, J.R. (2002). Biology. (Sixth Edition). San Francisco: Benjamin Cummings
    1.http://people.eku.edu/ritchisong/bird_excretion.htm1. (KL)
    2. http://www.pbs.org/lifeofbirds/home/index.html (NG)
    3. http://www.stanford.edu/group/stanfordbirds/text/essays/Temperature_Regulation.html (ZXU)
    (view changes)
    4:48 pm

Friday, November 19

  1. page Ferns edited ... Habitat: Ferns are commonly found in the tropics and are most diverse there, but many varieti…
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    Habitat:
    Ferns are commonly found in the tropics and are most diverse there, but many varieties are found in temperate forests. A few can grow in arid environments, but because their gametes use flagella to swim in reproduction, a damp environment is best.
    ...
    fern species).(4)(ZS)
    {Horsetails.jpg} {define-ferns-1.jpg} Fern (SR) (6)
    Major Types:
    ...
    Ferns have true roots and lignified vascular tissue. The roots pull up water and necessary minerals from the soil. The phloem brings sugar from sugar heavy photosynthetic areas, called sources, to sinks, areas with little sugar. The xylem brings water and minerals, mostly from the roots, to the rest of the pant.Just like a circulatory system, a transport system in plants is necessary to carry materials through the fern. The xylem transports water from the roots to the top of the fern through a series of connected vessels. These vessels pump the water from the bottom to the top quickly and efficiently. When a tree is cut open, the rings that are seen is left over xylem tissue. From the top, the glucose made by photosynthesis needs to be transported as well. This is done by the phloem. Phloem is always alive, but xylem dies after one year, which is why the rings inside a tree tell how old it is. (NG)(7)
    {repfern.gif} Reproduction:
    ...
    gametes). (ZXU)(2) Environmental
    Environmental
    Adaptations:
    Following
    ...
    new areas.(CW)(13) Review
    Review
    Questions:1. Describe
    ...
    ferns? (KS) Sources:Campbell,
    Sources:Campbell,
    Neil A.,
    ...
    (SM)4. http://en.wikipedia.org/wiki/Fern (ZS)5.(ZS)
    5.
    http://www.washjeff.edu/greenhouse/Pnudum/(YA)
    6. http://home.howstuffworks.com/define-ferns.htm (SR)
    7. http://www.biology4kids.com/files/plants_xylemphloem.html (NG)
    (view changes)
    12:33 pm
  2. page Ferns edited ... {repfern.gif} Reproduction: As previously mentioned, ferns have sporophyte dominant reproduct…
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    {repfern.gif} Reproduction:
    As previously mentioned, ferns have sporophyte dominant reproduction cycles, where the spores are larger than the gametophytes. Sporophytes are diploid cells (having two sets of chromosomes) which divide to produce spores, which are haploid (one set) reproductive cells. Unlike gametes, spores do not need to fuse with other cells to produce an organism. Spore production is done by plant organs called sporangia. On the undersides of fern leaves, clusters of sporangia called sori are arranged in patterns specific to the fern variety. The sporangia release the spores which develop into gametophytes, which have both sex organs. After fertilization and mitosis the fertilized egg develops into a new sporophyte. Sporangia are found on the underside of the fern's fronds, or leaves. They are usually in clusters, known as sori, and are often covered by a clear flap called the indusium. this setup protects the sporangia, while still allowing them to distribute effectively. Each sporangia has an annulus which catapults the spores out of the sporangium itself. After the spores germinate they produce gametophytes called prothalli which contain both antheridia(male gametes) and archegonia(female gametes). (ZXU)(2) Environmental Adaptations:
    ...
    Cummings, 2002. Print.1.http://amerfernsoc.org/lernfrnl.html(KL)2. http://www.biology-online.org/11/13_vascular_plants.htm3.Print.1. http://amerfernsoc.org/lernfrnl.html(KL)2. http://www.biology-online.org/11/13_vascular_plants.htm
    3.
    http://nefern.info/jpgs/notaxa/frndprts.BMP (SM)4. http://en.wikipedia.org/wiki/Fern (ZS)
    5.http://www.washjeff.edu/greenhouse/Pnudum/(YA)
    6.http://home.howstuffworks.com/define-ferns.htm
    (ZS)5. http://www.washjeff.edu/greenhouse/Pnudum/(YA)
    6. http://home.howstuffworks.com/define-ferns.htm
    (SR)
    7. http://www.biology4kids.com/files/plants_xylemphloem.html (NG)
    8. http://kmacphoto.net/ferns.jpg
    9. http://www.headlandamenity.com/cabadex/illo.jpg (MF)
    10. http://en.wikipedia.org/wiki/Fern10.http://en.wikipedia.org/wiki/Fern (RL)
    11. http://hiscreation.com/Gallery/slideshow.php?set_albumName=Plants

    11.http://hiscreation.com/Gallery/slideshow.php?set_albumName=Plants
    (CSR)
    12. http://plants.montara.com/ListPages/FamPages/ferns.html

    12.http://plants.montara.com/ListPages/FamPages/ferns.html
    (SD)
    13.http://www.gardenguides.com/131519-maidenhair-fern-adaptations.html
    14. http://www.botany.hawaii.edu/faculty/webb/bot311/bot311-00/celltissorgan/Pterophyta.htm14.http://www.botany.hawaii.edu/faculty/webb/bot311/bot311-00/celltissorgan/Pterophyta.htm (LW)
    (view changes)
    12:31 pm
  3. 12:28 pm

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