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Biology

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Biology

Post  Joe_Morningstar on Wed Feb 10, 2010 6:10 am

1. The virus is made up of five parts and is in the size range of 10
nm-300 nm in diameter. The first is the coat made up of protein that protects
the virus to a point. Next is the head that contains the genetic material for
the virus. The genetic material for a virus is DNA. The two other parts are
the tail sheath and the tail fibers that are used for odd jobs. I believe that a
virus is not considered to be a living creature due to the fact it is a
parasitic reproducer. To me it is just like ripping up a piece of paper because
it is still the same thing and it isn't carrying out any other function besides
reproduction. Since the virus cannot continue to do its functions without
taking from a host and being a parasite it is considered an obligated parasite.


2. The adult fern plant in its dominate generation (sporophyte)
develops sporangium on one side of its leaf. When meiosis is finished inside
the sporangia and the spores are completed the annulus dries out releasing the
spores. The spore germinates and grows into a prothallus which is the
gametophyte generation. The antheridia and the archegonia are developed on the
bottom of the prothallus. The archegonia are at the notch of the prothallus and
the antheridia are located near the tip. Fertilization occurs when outside
moisture is present and the sperm from the antheridia swim to the eggs of the
archegonia. A zygote is formed on the prothallus and a new sporophyte grows.

4. Flowering plants have unique characteristics that help them survive.
One is the flower itself that contains the reproductive structures. The color
of the flower helps because it may attract birds and insects that spread the
plants pollen which diversify the later generation of plants. Flowers also
produce fruits that protect their seeds and disperses them with the help of
fruit eating animals.

5. Fungi, Animalia, and, Plantae are all believed to be evolved from
Protista. All 3 of these kingdoms are eukaryotic and their cells have a nucleus
and all the other organelles. Fungi live on organic material they digest,
Plants produce their own organic material, and Animals go out and find their
food. Animalia are heterotrophic whereas Plantae are photosynthetic. Fungi who
digest their own food on the outside are different from animals who digest their
food on the inside. Plants and animals both have organs systems but animals
have organized muscle fibers and plants do not.

8. The Gasreopoda , Pelecypoda, and the Cephalapoda all have three of
the same characteristics. The first one is the visceral mass that includes
internal organs like a highly specialized digestive tract, paired kidneys, and
reproductive organs. The mantle is the second one. It is a covering that
doesn't completely cover the visceral mass. The last one is the foot that can
be used for movement, attachment, food capture, or a combination of these. The
Gastropods are the snails and slugs. They use their foot for crawling and their
mantle (shell) to protect their visceral mass. The class Pelecypoda consists of
clams, oysters, scallops, and mussels. These animals have two shells that are
hinged together by a strong muscle and these shells protect the visceral mass.
They use their foot for making threads so they can attach to things. Cephalopods
consist of octopuses, squids, and nautiluses. These guys use their mantle
cavity to squeeze water out and causes locomotion. The foot has evolved into
tentacles around the head that are used to catch prey. Nautiluses have an
external shells, squids have smaller but internal shell and octopuses lack
shells entirely.

9. The word Arthropod means jointed foot which come to some of the
features of an arthropod that are the jointed appendages, compound eyes, an
exoskeleton, and a brain with a ventral solid nerve cord. The class Crustacea
has compound eyes and five pairs of appendages two of which are sensory antenni.
Some examples are shrimp, cray, lobsters, and crabs. Insecta has 900,000
species in its class. For example in a grasshopper they have compound eyes with
five pair of appendages, three that are legs, one of which is for hopping, and
two pairs of wings. Spiders that belong to the class Arachnidia have six pair
of appendages. The first pair of appendage are modified fangs and the second
pair are used for chewing. The other four are walking legs ending in claws.
Spiders don't have compound eyes, instead, they have simple eyes. More examples
are scorpions, ticks, mites, and chiggers. To similar classes are Diplopoda and
Chilopoda because they are segmented in the same way and each segment has a pair
of walking legs but in the Diplopoda some segments fuse together and seem to
have two pair of legs to one segment.

10.The Phylum Chordata contains creatures that would have bilateral symmetry,
well developed coelom, and segmentation. In order to be placed in this phylum
they must have had a dorsal hollow nerve cord, a dorsal supporting rod called a
notochord, and gill slits or pharyngeal pouches sometime in their life history.
In the subphylum Urochordata the only one of the three traits they carry on into
adulthood is the gill slits. In their tadpole form of their life they contained
all three of these characteristics. Subphylum Cephalochordata retain all three
qualifications into adult form and have segmented bodies. In subphylum
Vertebrata it has all three traits as usual but its notochord is replaced by a
vertebral column.

11. In these fish the sac-like lungs were placed at the end of the
fishes digestive tract. In their case when the oxygen level in the water they
were in was low they could still collect oxygen by breathing. After time these
sac-like lungs became swim bladders that control the up and down motion of a
fish.

12. The reptiles most helpful advancement in reproduction that helped
them live on land was the use of internal fertilization and the ability to lay
eggs that are protected by shells. The shells got rid of the swimming larva
stage and the eggs did everything inside of the shell. The eggs has
extraembryonic membranes that protect the embryo , get rid of wastes, and give
the embryo oxygen, food, and water. Inside the shell there is a membrane called
the amnion and is filled with fluid and is used as a pond where the embryo
develops and keeps the embryo from drying out.

13. The three subclasses of mammalia all have hair and mammary glands
that produce milk. Each of these classes also have well developed sense organs,
limbs for movement, and an enlarged brain. In the subclass Prototheria the
animals lay their eggs in a burrow and incubate. When the young hatch they
receive milk by licking it off the modified sweat glands that are seeping milk.
Subclass Metatheria the young begin developing inside the female but are born at
a very immature age. The newborn crawl into their mothers pouch and begin
nursing. While they are nursing they continue to develop. With the subclass
Eutheria the organisms contain a placenta that exchanges maternal blood with
fetal blood. The young develops inside the mothers uterus and exchanges
nutrients and wastes until it is read to be born.

Joe_Morningstar

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