Computers 3

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.