Wednesday, May 24, 2006

Reptile Podcast


Here is the class’s first attempt at a Podcast. The class had the unique opportunity to Interview World renowned reptile expert form the National Geographic Channel, Dr. Brady Barr. Each group had a set of questions to ask the expert. The interview was then used in a fictitious radio station broadcast. We had allot of fun with the project and want to thank Dr. Brady Barr publicly for offering his time and expertise.

  • Click here to listen to group one's podcast consisting of Nicole, John Amber and Andrew interview Dr. Barr about the "American Crocodile."
  • Click here to listen to group two's podcast consisting of Sheena, Cresheva and Briancca interview Dr. Barr about the "American Alligator".

Thursday, May 04, 2006

26.4 Phylum Nematoda

Phylum Nematoda
*The phylum Nematoda is made up of roundworms with long slender bodies that taper at both ends.
*Roundorms are among several phyla of pseudocoelomates.
*Roundworms have a digestive tract with two openings.
*Most species are free-living; some are parasites.
Ascaris
*The genus Ascaris infects pigs,horses,and humans.
*The eggs enter hosts through contaminated food or water, develope into larvae in the intestines, and can infect the lungs.
*The eggs are spread in the hosts' feces.
Hookworms
*Hookworms are intestinal parasites that feed on blood.
*The eggs produce larvae in soil, and the larvae enter hosts through the feet.
*Hookworms infect about one billion people worldwide.
Trichinella
*The genus Trichinella infects humans and other mammals.
*Adults live in intestines and larvae form cysts in muscles.
*People usually become infected from undercooked pork.
*Infection causes the disease trichinosis.
Other Parasitic Roundworms
*Pinworms, genus Enterobius, are common parasites of humans. They do not cause any serious disease.
*Filarial worms infect many people in tropical countries.
The most dangerous ones infect the lymphatic system and may cause elephantiasis.


THE NEXT BLOGGER WILL BE JE'LISA BAILEY

26.3 Platyhelminthes

Structure and Function of Flatworms
*The phylum Platyhelminthes inclides organisms called flatworms.
*They are more complex than sponges but are the simplest animals with bilateral symmetry.
*They are acoelomates (no body cavity)
*They exhibit cepholization (have a head)
Class Turbellaria-Planarians
Digestive and Excretion in Planarians
*The most familiar turbellarians are the freshwater planarians.
*Planarians feed on decaying plant or animal matter and small organisms.
*Food is ingested through the pharynx
*Planarians eliminate excess water through a network of excretory tubules.
*Each tubule is connected to several flame cells where water is excreted.
Nueral Control in Planarians
*The Planarians nervous system is more complex than the nerve net of cnidarians.
*The cerebral ganglia serveas a simple brain.
*A planarian's nervous system gives it the ability to learn.
*Planarians sense light with eyespots.
*Others sensory cells resoond to touch, water currents, and chemicals in the environment.
Reproduction in Planarians
*Planarians are hermaphrodites that can reproduce sexually or asexually.
*During asexually reproduction, their body undergoes fission and the two halves regenerate missing parts.
Class Trematoda
*The class Trematoda consist of parasistic flukes.
*Some are endoparasites;others are ectoparasites.
Structure of Flukes
*A Fluke clings to the tissue of its host by on anterior sucker and a ventral sucker.
*A Fluke's nervous system is similar to a planarian's but simpler.
Reproduction and Life Cycle of Flukes
*Most Flukes have highly developed reproductive systems and are hermaphroditic.
*Flukes have complicated life cycles the involve more than one host species.
*For example, the trematocle blood flukes of the genus Schistosome use humans as a primary host. They can cause schistosomiasis.
Class Cestoda
*About 5,000 species of tapeworms make up the class cestoda.
*Tapeworms can live in the intestines of almost all vertebrates.
Structure of Tapeworms
*Tapeworms are surrounded by a tegument.
*They attach to the host w/a scoley.
*The body is a series of many.
Sections called proglotius
*Tapeworms have no light-sensing organs,no results,no gastrovascular cavity,and no digestive organs.
Reproduction and Life Cycle of Tapeworms
*Nearly all tapeworms are hermaphrodites.
*New proglottius are added to the front of the tapeworm. Older proglottius grew,mature, and begin producing eggs.
*Eggs in one proglottius,are usually fertilized by sperm from a different proglottius,possibly a different individual.
*An example is the beef tapeworm, Tuenia saginatus. Its primary host is a human and its intermediate host is a cow. Its larvae form cysts in the muscle tissue of the cow.

Tuesday, April 25, 2006

Killer Jellies


Explain how the killer box jellies can cause death in unsuspecting swimmers.

Monday, April 24, 2006

Cnidarians

BODY PLAN OF CNIDARIANS
- Animals in the phylum Cnidaria are radially symmetrical aquatic invertebrates that are more complex than the sponges. They have tissues and simple organs.
- The cnidarian body is either a sessile polyp or a swimming medusae. Some cnidarians alternate between both types during their life cycles.

The body of a cnidarian consists of two cell layers:
1) an outer epidermis
2) an inner gastrodermis
- The layers are separated by the mesoglea.
- The gastrovascular cavity has a single opening (the mouth) surrounded by tentacles.

FEEDING AND DEFENSE IN CNIDARIANS
- Cnidarians have cells called cnidocytes.
- Each cnidocyte contains a nematocyst.
- When a cnidocyte is stimulated. its nematocyst (stinger) ejects a filament that can paralyze or ensnate prey.

NERVOUS SYSTEM IN CNIDARIANS
- The cnidarian nervous system is a diffuse web of interconnected nerve cells called a nerve net.

CLASSIFICATION OF CNIDARIANS
- The three classes of cnidarians are:
1) Class Hydrozoa
a) This class includes Obelia, man-o-war, and the hydra.
b) Hydrozoans may live as polyps, medusae, or mixed colonies.

2) Class Scyphozoa
a) This class includes jellyfish.
b) Scyphozoans spend most of their lives as medusae.

3) Class Anthzoa
a) This class includes anemones and corals.
b) Anthzoa only live as polyps.

Today's objectives were: Complete 26.2 discussion, 26.2 Cnidarian Section Review, and TEST THURSDAY on 26.1 AND 26.2

The next blogger is Ashley

Thursday, April 20, 2006

Sponges

What are Sponges?

-Sponges are in the phylum Porifera which means pore-bearer.
-Sponges are asymmetrical aquatic animals that have a variety of shapes, sizes, and colors.
-Most sponges live in a marine environment
100 of 5000 live in fresh water
BODY PLAN
-Sponges are sessile invertebrates that have no true tissue or organs. A simple sponge is hollow cylinders.
-The body wall is made of two layers of cells seperated by jellylike substance called meshyl.
Choanocyes-is the inner layer that draws water.
Ostia(pores)-the penetrate the body wall. Water leaves through the osculum.
-The body is supported by a skeleton made of spongion spicules or both.
*Pore cell(ostio)-Bring water carrying food and oxygen into the sponge.
*Epithelial Cells-thin,flat cells control opening in pore cells.
*Colar cells(choanocytes)-Flagellated cells that line the inner surface of a sponge.
*Amoebocytes-locted between the two cell layers, carry nutrients and aid in reproduction.
*Spicules-form the hand support system of sponges.
FEEDING AND DIGESTION OF SPONGES
Sponges can reproduce asexually through:
producing buds or gemmules
regenrration of missing parts
Budding new sponges that break off and form new sponges
They reproduce sexualy through the joining off egg and sperm.
Most sponges are hermaphrodites, which can produce both egg and sperm.
The next blogger is Nicole.

Thursday, March 30, 2006

zygote development


zygote development
Originally uploaded by rfullington.
What does the illustrated process show about the differences in patterns of embryology among kinds of animals?

Hello. Here are your notes from today's lesson.

Today in class we discussed Section 2 of Chapter 25.


  • Symmetry- A balance in proportions of an object or organisms; close agreement in size, shape, and relative position of parts arranged on opposite sides of a dividing line or plane or around a central point.
  • There are three different types of symmetry. Spherical, Radial, and Bilateral symmetry.

  • Spherical symmetry- occurs when any plane divides the body into mirrored halves.
  • Radial symmetry- occurs when any longitudinal plane passes through a central axis divides the body into mirrored halves.
  • Bilateral symmetry- occurs when an organism can be divided down its length(midline) into similar right and left halves.

  • Asymmetry- is an animal that has an irregular shape. (has no symmetry)

  • Body Regions
  • Planes of animal symmetry

  • Body Regions
  1. Anterior indicates the head end; the opposite or tail end is Posterior.
  2. Dorsal is the back side and Ventral is the front or belly side.
  3. Medial is the midline of the body; Lateral is the sides.
  4. A Frontal plane divides the body into Dorsal and Ventral halves.
  5. A Sagittal plane divides the body into right and left halves.
  6. A Transverse plane separates Anterior and Posterior portions.
  7. In vertebrates, Pectoral is the chest region or area supported by forelimbs.
  8. Pelvic refers to the hip region or area supported by hind limbs.

Comparison of body plans.

Coelom- a fluid filled space

3 Types of Body Plans

  1. Acoelomate- no cavity.(flatworm)
  2. Pseudocoelomate- False body cavity, surrounded on one side by mesoderm ( round worm)
  3. Coelomate- true body cavity. surrounded on both sides by mesoderm ( segmented worm)

Animal

Exoskeleton- Hard, waxy covering on the outside of the body that provides a framework for support. Exoskeletons are found on animals that are invertebrates. Their exoskeletons Do not grow with the animal, so they have to shed it. Exoskeletons are a good source of protection.

Molting- The process of shedding the exoskeleton.

Endoskeleton- internal skeleton that provides support inside an animals body. Endoskeletons are found within vertebrates, animals with a backbone. and it grows with the animal.

For homework Do the section 2 assessment for chapter 25.


Next person to scribe will be Nicole Norton.. Love you all.... See ya. O, and Nicole have FUN with the next scribe......

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!!!