Earthworms and sea stars and crayfish, grasshoppers are taste

earthworms are cool because I didn't think that they had a brain or organs I don't know why but  I thought they where really cool. 

the sea stars where really cool because i hadn't looked at one by cutting them open and in a way they had less than I thought they would and it was a good surprise.


I can't wait to see what the crayfish look like.

I'm excited to see what is inside the grasshopper because i ate one when i was 4 so I'm excited to see what I ate and if I'm grossed out or want another soon!

Earthworms and Sea Stars -- cool!

In yesterday's class, we started class by talking about an unbelievable property of some hydras that I hadn't fully known about before -- some scientists think they may be immortal!  No one has found evidence that their cells age and deteriorate the way all other life forms do.  Here is information about an article that you can get for free about a study looking at this, and they found that in four years of study, hydras didn't seem to age or die, and reproduction stayed the same.  They compared hydras with several other species that show the normal pattern of growth, reproduction, then decline in reproduction and then death, and found that hydras don't show evidence of aging and death!

Next we did a lively and entertaining classroom quizshow on planaria and mussel, which we dissected last class.  It was a close game, with the Planarians taking an early lead and the Mussels then trying to catch up.  In the end, it was the Planarians who won, 2 to 1, but everyone did a great job and had fun.  Some facts we reviewed that I didn't mention in my last post included:

• Planaria can live in water or on land.
• They are carnivores and eat living or dead small animals.
• Mussels are bilaterally symmetric (I had been confused about this!)
• They are mostly freshwater animals and have very strong muscles for moving and keeping their shells closed.
• Zebra mussels were originally native to streams of southern Russia, and are now an invasive species in North America, including Wisconsin.

The rest of class was focused on earthworms and sea stars.  For homework, students accessed the online earthworm species database, where you can find out the names of all the earthworm species that have been characterized.  We each looked up how many species of earthworms were named in the year we were born.  Here's what we found:

• My birth year of 1973:  38 species, one of which was Platydrilus simplex
• Year   # of earthworms named  (students' chosen species)
• 1998   32
• 1999   65  (Amynthas sexpectatus, Amynthas binoculatus, Dendrobaena Negevis)
• 2000   389
• 2001   37
• 2002   40  (Cubadrilus barroi)
• 2003   13  (Proandricus lovuus)
• 2004   94
• 2005   34

As we could all see, it's amazing how many species of earthworms there are in the world, and to see that people from all over the world are naming and characterizing new ones all the time!  One fact I found about earthworms is that the Maori people of New Zealand use the word Noke for earthworms that they eat as delicacies.

We dissected earthworms and could see that they are bilaterally symmetric, have lots of organs (including five hearts!), and are hermaphrodites.  They have a digestive tract all down through them, have little spike things on the bottom to help them move, and most of ours had over 100 segments!

Next, we talked about and dissected sea stars.  We learned that sea stars can regenerate arms and saw that several of the sea stars we had appear to have been growing an arm back, because one was smaller than the rest.  Sea stars are radially symmetric, and they have little foot structures on the bottom to help them move.  Their mouth is on the bottom in the middle, and they have a tiny round spot on top that they use to suck water in.  They do not have a backbone and are invertebrates, like all the other animals we've studied so far.  

We have two more invertebrates to study next week, the grasshopper and the crayfish, and then we'll do a big invertebrate review quizshow and move on to a hemichordate (missing link between invertebrates and vertebrates) and then to the chordates (vertebrates).  Very cool stuff!

week four class

We studied the hydra,sponge,planaria,and mussel. The one I enjoyed to do the most was the planaria because we could see the eyes.I feel really exited to do more .I am excited to dissect the sea star because I never knew you could dissect one.

Week Four Class

I really enjoyed class last week because we we're able to learn and dissect all of the animals in just two days but that I didn't feel rushed with dissecting the specimens.
I learned that the Planaria has two half brains.
I also thought that the best part of class was the classroom quiz show.
I am looking forward to dissecting the Sea Star this week because it is a real change from last week because this is the average size of a Sea Star so that will help enable us to dissect the Sea Star instead of just looking at it in a microscope.
I would really like to do the classroom quiz show every week because I believe that it gave us some motivation to take notes in class.

Jett's second blog post

my favorite animal we dissected was the mussel. I learned that mussels don't have a brain. I love dissecting animals and learning about them. and i am very excited about them both.
Jett.

Four dissections! Woah!

Well, we tackled four animals in two days!  Pretty awesome.  They were pretty small, though, so it actually wasn't as big a deal as we thought.

We looked at sponges, and our sponge was very tiny.  I'd guess it was about 1 cm long, and irregularly shaped.  We discussed the concept of symmetry, which is basically whether you can find one or more lines through the object that if you placed a mirror there the reflections would line up.  The sponge was not symmetric, or asymmetric.  One resource for if you want to learn about species of organisms that live in the ocean is the WoRMS, or World Register of Marine Species.  Some interesting facts we learned about sponges:

• Sponges have no true tissue layers
• There are about 5,000 to 10,000 species of sponges
• They eat bacteria and plankton
• They suck water and food in through pores and then shoot it out the opening at the top
• Sponges don't really move around
• Recently, the genome of a sponge-associated bacteria that produces various potentially useful chemicals has been sequenced.  Here is the article I tried to explain

Next we looked at hydras, which are in the phylum Cnidaria.  That is the same phylum as jellyfish, which really should be called jellies (because they're not fish).  The hydras looked like tiny strings, about 5 mm long and less than 1 mm wide, floating in liquid.  We placed them on slides and looked at them under my microscope.  They were like a long tube and had long, stringy tentacles on one end.  Their bodies and tentacles were greenish like algae, and we decided that they probably look that way in order to blend in with algae but couldn't actually be photosynthetic because they're animals.  Other facts:

• Hydras are radially symmetric
• They have a tubular body with a foot at one end and tentacles at the other
• The tentacles have specialized stinging cells that paralyze their prey
• Hydras don't have brains
• Food comes in through the top opening and waste leaves out the same opening
• They eat plankton
• When food is plentiful, they reproduce asexually by budding
• In harsh times, they reproduce sexually
• In a commentary article we looked at, we learned that studying the stinging cells of hydras has led to some interesting ideas about how sensory cells evolved (cells that sense things, such as hearing-related, sight-related, touch-related, etc.)

At our next class, we started by having a game show about sponges and hydras.  It was really fun because the class was divided into two teams (called the Hydras and the Sponges), and each team really wanted to win.  We used questions that the students created, and alternated players from each team.  Some of the questions were harder than we thought they would be, and if a player got the question right, they could choose a spot on a tic tac toe game.  The final score was Hydras 2 Sponges 0.  

Next we started talking about planaria, which are tiny, free-living (not parasitic) flatworms.  They were hard to dissect because they were less than 1 mm thick and maybe 3 mm long.  But they were too big to look at with my microscope.  So we mostly talked about the cool things about planaria, such as:

• They are bilaterally symmetric, which means you could draw a line down the middle and each side is a reflection of the other
• They have a head area that has two eyespots, but the eyespots aren't really eyes -- they just detect light
• They move using cilia, and glide along a layer of mucus (ew!)
• Planarians have a remarkable ability to regenerate body parts or even whole worms!
• They have a single opening digestive tract (food goes out the opening it came in)
• They have a tiny brain on each side of the head and nerve cords that go down the animal
• They can reproduce asexually or sexually and are hermaphrodites (have both male and female reproductive parts
• Studies have been done on memory in these worms, and there are kits you can get to train worms yourself
• Neuroscientists have been looking at planarians to learn about neuropharmacology (the study of drugs and chemicals in the nervous system)

Lastly, we discussed and dissected a mussel.  We're pretty sure it was a zebra mussel, and it was tricky to cut the right muscle to get the shell to open.  Compared to the other animals we had looked at before, this animal has a lot of structures and organs.  Some facts we learned:

• Mussels are in the phylum Mollusca and class Bivalvia
• The shell has three layers, and the inner layer is the iridescent mother-of-pearl
• The foot is a large, muscular organ that pulls the animal around
• They eat plankton by pulling it in using a siphon
• Waste is eliminated using a different siphon, so they have a digestive tract (sortof)
• Mussels reproduce sexually, and there are males and females
• They have a basic nervous system
• They have a heart, but they don't have blood vessels
• I didn't have time to discuss the research article related to mussels, so that will be for next time

Wow!  What a pair of classes!  We had them back to back due to last week's class being cancelled and scheduling the make-up class for this week.  

The digestive system for the sponge planaria mussel hydra.

The sponge uses cells to digest all of the sponges food.The hydra is green to look like algae in the water and uses its tentacles to paralyze its pray.
 The planaria has two little brain's the planaria is also a type of flat worm.the hydra has 4 to about 25 tentacles.The planria digests within the cavity.
The mussel has areal digestive system, where food geus in one end and comes out the other.

 

 

Sponge

I liked today's class the sponge and hydra were not what i expected but they were cool.I cant wait for the next class to see the things we are going to dissect.

HYDRA SCHMYDRA

I learned that hydras have wolverine-like abilities of regrowth. I want to know what would happen if you cut a hydra in half. I am obviously very excited to dissect the hydra.

I learned that some kinds of sponges that can shoot a part of there bodies of really far that then turn into genetic copes of themselves. i'm exited to dissect sponge to learn more about them.  

Mussels and Sponges

Mussels are in the kingdom Animalia and eat by filtering water and eating the bacteria in the water they filtered. I'd also like to know if sponges were ever used as cleaning sponges. It would be cool if we learned more about mussels.              

Esme's post

I love this class because I am learning about a lot of cool stuff like the five parts of the animal kingdoms and I'm going to learn more cool stuff like that.

The Sponge

I learned there are two layers in the sponges body.I am curious to learn more about the planaria.I am excited to dissect the snake

zebra mussel

I learned the zebra mussel is a freshwater mussel.
I want to learn more about the planarians.
I'm  curious about the hydra and the Planarians.

Week One Class

I really enjoyed class last week because we went around the room and tried identifying plant species.
I thought it was amazing that so many bugs and worms lived on earth.
I would really like it if sometime in the future we would be able to go to the UW and check out their collection of micro wasps.
Also I wasn't able to make a post so I decided to just write a comment instead of a post.

The Sponge

I thought that the sponge was very interesting because there are so many types of Sponges and how some Sponges live in saltwater and some live in freshwater. 
I am very excited to dissect the sponge because it looks very interesting because it can compress into a very small size and then expand into a larger size.
I am also very excited to dissect the snake because it will likely have different animals in its stomach that it had eaten, so it's like two animals in one.

Henry  

Dissecting invertebrates

I think all of the animals that where going to dissect this week are very interesting because they are different than any thing we have or will dissect. The reason I say that is because they are invertebrates and don't have any bones at all. This interests me because you can dissect them in your own home, and the fact that they move with no bones. 

i can't whit to dissect the Hydra

dissecting the hydra is going to be so much fun i can't whit. i want to learn more about the hydra.

Jett's post

 I learned that sponges eat plankton. I want to know more about hydra. i am excited about dissecting a frog.

the most interesting one the sponge

well they are filtered feeders  they eat plankton like from sponge-bob  they can make clones the parents can be male or female there are  a lot of different species of sponge 

Hydras are interesting!

In my homework I liked those links to hydras and sponges.  I learned that some hydras secrete a slime that must be cleaned from the tank if you have one.  They have a liking for beef and fried egg.  I think it is cool that some species eat and expel their food from the same end.  It was great to have the links in our homework leading to Wikipedia.  Most sponges that we use at home are synthetic, which means that they are not natural.  I am looking forward to dissecting the hydra in the future.  I don't know what variation it will be, so I don't know what to expect.  Anne Sophie

History of Life, Darwin, and a Quiz Show!

We spent much of class exploring the history of life on earth.  Our timeline included:
- the formation of our planet, earth, 4.6 billion years ago
- life's beginning on earth, with simple, single-celled, bacteria-like organisms, 3.6 billion years ago
- complex cells (eukaryotes), 2 billion years ago
- multicellular organisms (like protists), 1 billion years ago
- simple animals, 600 million years ago
- arthropods, 570 million years ago
- fish, 500 million years ago
- land plants, 475 million years ago
- insects and seeds, 400 million years ago
- reptiles, eventually including dinosaurs, 300 million years ago
- mammals, which were small until the dinosaurs went extinct, 200 million years ago
- birds, which may have evolved from dinosaurs, 150 million years ago
- flowers, 130 million years ago
- the extinction of dinosaurs, 65 million years ago
- the Genus Homo, which now includes modern humans, appeared 2.5 million years ago
- Homo sapiens, our species, appeared 150,000 to 200,000 years ago
(this is pretty much from Wikipedia)

We also talked about Darwin and how he gathered the information that later led to his theories about the origin of species and evolution.  Mainly, we learned that he went on a voyage to several places around the world, including the Galapagos Islands, and collected many specimens -- various plant and animal species to learn about.  The trip ended up being five years, and Darwin didn't initially know much about what he was doing or the significance of what he was seeing and collecting.

We went outside to look at what species we could see right in the back yard, and we saw insects (bumblebees, a hornet, and a junebug), birds, trees, flowering plants, grasses, and two mammals (squirrels and a rabbit).  So we got a feel for what it was like on Darwin's trip, looking at and collecting specimens of life forms.

Lastly, we divided into teams and had a quiz show about what we learned in class.  The final score was 2 to 1, but the point, of course, was just to have fun!

I liked how many bones I found in the owl pellet. The skull was cool.  I liked the bones so much I took them home!

I'm excited to learn about evolution and I want to learn more about disecting.

Owl pellet Recap

I really liked the ability to pull apart the Owl pellet.  I thought it was fun and cool to see the bones.

There is not always a full skeleton, sometimes there is half a skeleton of one and half a different skeleton of another, and sometimes there is just half.

I think you did a good job explaining every thing.

Last week we dissected owl pellets and I got a big one and found a lot of rat bones such as two skulls and tons of ribs.  I had fun and I learned a lot.