Tuesday, March 28, 2006

What is an animal? Ambie is about to tell all.

1. Typical Animal Characteristics

a. Eukaryotic- cells contain membrane bound organelles.
b. Multicellular- cells form tissues and organs.
c. Heterotrophic- depends directly or indirectly as autotrophs.
d. No cell wall (plants do have a cell wall)
e. Animals are motile and sessile (motile means they move, they don't move if their sessile, although most animals that are sessile where motile as larva)

Fertilization- The union of male and female gametes. may occur internally or externally. Most animals produce sexually. One type of animal that dosen't produce sexually is the Hydra.

2. Cell Division
a. Blastulation- Clevage results in a clustor of cells called a blastula or blastocyct. Cells arrange themselves around a fluid filled cavity called a blastocoel.
b. Gastulation- The formation of germ layers. Develope into all the different tissues in your body. The gastrula is a structure made up of two layers of cells with an opening at one end. gastrulation converts the spherical blastula into a more complex configuartion of three germ layers.
c. Endoderm- gives rise to the epithelium of the body and nervous system.
d. Mesoderm- gives rise to the muscular, circulatory, excretory, respratory and reproductive system.
e. Endoderm- gives rise to the lining of the digestive track and organs associated with digestion.

In some animals, the opening in the gastrula becomes the mouth (protostome) in others it becomes the anus (deuterostome) humans form their anus first. Coach says some people stay that way, but I don't see that in the book.

3. Continued Growth and Development

a. Cells in developing embryos continue to change shape and specialize to perform different functions.
b.animals embryos develope into either a Juvenile a smaller version of the adult, or a Larva the intermediate stage of an adult. Larva don't look anything like the parent basically.

For the homework, do the section assessment on page 699, problems 1-6. Do not write the questions.

Hope you enjoyed reading my notes I know I enjoyed writing them, and the new scribe is Rachel!!! Okay luv ya everybody bye!!!


At 5:17 PM, Blogger Ashley said...

good notes....good thing the hw was there i almost forgot about it!...lol


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