Wednesday, January 25, 2012

Compare contrast Rat to Human

Digestive system.

Similarities
-both have three main areas of digestion; salivary glads, oral cavity, and abdominal cavity.
-Both omnivores

Differences
-rats have no gall bladder
-rats have a bile duct, which makes them graze constantly, they never have the feeling of being full
-rats do not have a uvula
-when food enters the caecum of the rat, nutrients is absorbed.

Respiratory system.

Similarities
-both use the respiratory system to exchange carbon dioxide and oxygen with surrounding air.
-Two part system; upper and lower tracts

   Upper contains nasal passages, the larync and pharyx.
   lower contains lungs, trachea, and bronchi.

Differences
-There are not many differences except small minor things.

Circulatory system

Similarities
-both have a four chambered heart, meaning blood flow goes through:
1. vena cava (massive vein)
2. RA (right atrium)
3. RV (right ventricle)
4. respiratory organ (lungs)
5. LA (left atrium)
6. LV (left ventricle)
7. Aorta (massive artery)       
8. the body.

Differences
-Agan minor differences, but rats hearts are smaller and beat faster.

Thursday, December 15, 2011

Compare and contrast between an Earth Worm and a Crayfish

Movement
Worm
-The worm has setae on the bottom of its body that run along down its body that help it have grip so it can move along.  The worm moves from waves of muscular contractions which shortens and lengthens its body.
Cray fish
-Cray fish move with there legs, but also flip there tail fast nd repeatedly

Reproduction
Worm
-The earth worm is a hermaphrodite, meaning it has both eggs and sperm.  The worm releases both into a cacoon made of mucus, then the sperm will fertalize the eggs and create a new worm.
Cray fish
-Males produce a package of sperm and place it on the female, the female curls up her abdomen in and places the eggs on her swimmerets.  They are placed on the swimmerets because they are protected and get oxygenated.

Habitat
Worm
-the earth worm lives in soil and produces a mucus to make the soil moist so they can stay deep in there burrows.  The earth worm breathes through its pores on its body.
Cray fish
- cray fish live in fresh water, ponds, and in salted water.  The cray hide under mud, rocks, and grass to proctect themselves from predators. Pregnant females are especially likely to do this.  Cray fish breathe from gills that are located under the capace, water containing oxygen then flows over the gills.

Nervous system
Worm
-The brain is connected to the ventral nerve cord which runs down the body.  At each segment, segmental ganglion brach off from the cord, which connects every segment to the brain
Cray fish
-A nerve cord that functions on escape responses

Thursday, December 8, 2011

Animal Phyla

Today we looked at different Invertebrate animals and had to find out what phyla they belong to. 

Tuesday, December 6, 2011

What I learned today. Dec.6th

Stem cells.
-There are different types of stem cells.  There are adult stem cells and there are embryotic stem cells.  Adult stem cells have some differentiation, they are more limitted but they can become more then one kind of cell.  Embryotic stem cells are before differentiation.  They can't be more then one kind of cell.
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Symmetry of segmented worms, round worms, and flat worms. 
Each of these worms are bilaterally symmetrical.  This means, each left and right side are equivalent to each other.  Being bilaterally symmetrical helps with the movement of the animal.  It gives a much stronger sense of direction.  Animals that aren't bilaterally symmetrical e.g a jelly fish, when moving they don't have very strong control over their direction. 

The different environments of segmented worms, round worms, and flat worms.
*segmented worms- They can live in most environments excpet frozen soil of the polar regions, and dry sand.
*round worms- Round worms live in fresh water and marine environments
*flat worms- flat worms live in fresh water environments


In this image, to the right, you see an example of bilateral symmetry.  As you can see,having both equal sides, would definitely help your movement.

Monday, December 5, 2011

Intro to animal characteristics.

Animal characteristics.
*Heterotrophic-feeds on organic matter
*Ingest food-takes in food from there mouth
*primarily diploid
*sexual reproduction
Animals go through dictinct development, but there are two different types of development; Gradual, and metamorphosis.
Animals are highly specialized. they have a variety of cells with specific functions.
There are two groups of animals, invertebrates, and vertebrates. Invertebrates are animals without back bones. Phyla porifera, cnideria, platyhelminthes, nermatoda, annelida, mollusca, arthropoda, and echinodermata.
Vertebrates are animals with back bones, within phylum chordata e.g fishes (cartilagenous, bony) amphibians, reptiles, aves (birds) and mammals