squid dissection

It seems to be on Fridays we do all the fun things but I don't mind, last Friday we got to dissect squids! Its really enjoyable and helpful to have a visual in front of me whenever we learn new units on bio. Last time when we did the earthworm dissection I was "Dr. Marissa" but this time it was Liz doing all the work while I was answering the questions. I learned/saw things I wouldn't think I was gong to find in a squid such as the beak, all the small organs or that they both had tentacles and arms! Although taking pictures of the squids organs was hard to tell what was what because everything was smushed together even having a clear picture beside us was kind of a challenge to point things out. When we found the pen I wasn't quite sure what it was because it really looked like plastic until I touched it it, thinking it would be flimsy I found out it was firm. Knowing we could write with the pen hense the name with the ink sac was pretty cool even though it broke right away. I learned squids have three hearts and they move tail first instead of head first in water. Here are some pictures i took and facts that I learned! (:

-How many arms does your squid have? How many tentacles?:
Our squid had 2 arms and 8 tentacles.
-Describe how tentacles and arms purpose differs. Describe the direction water comes out of the funnel and the direction the squid moves:
Arms are used to grab prey and hold on to it, the suckers on the tentacles aid to feed and grasp if the prey or object tries to escape. The squid moves opposite to the direction the jet is propelled from while the funnel collects water into the mantle cavity.
-Name two external features that are adaptions for the squids predatory life. How do these adaptations help the squid?:
1. They have a sharp beak that works as a shredder for food.
2. They either have small hooks or rings of teeth around their suckers.
-Name two traits that the squid shares with other mollusks:
Squids and mollusks both have a true coelom and bilateral symmetry.

-How many pairs of gills does the squid have?
Our squid had 2 gills in total.

-Where does the ink sac empty into and what is its function?:
The ink empties into the water to hide them selves, and surprise predators trying to eat it.

-What is the function of the pen? What would happen if the squid didn't have a pen?:
The pen is the squids bone structure which helps it keep stable to swim around, if the squid didn't have it its body would flop around and collapse on its self.
-How do you think wastes exit the squid?:
I think the squids waste would enter through the anus.

DR. Liz!

Earthworm Dissection Questions

On Friday my bio class got to dissect annelids which is a round worm like animal that has a segmented body, such as an earthworm. When I was in elementary I had always wondered why earthworms came out on rainy days, always stopped to pick them up, feel their slimy bodies and see their reactions or how they moved around a lot in the hot sun because they were literally being fried. At first knowing that we had to cut from its mouth to its anus, got me feeling iffy about it because I'm not really into cutting flesh, I find it weird and disturbing. Cutting their little bodies up was a no-no for me, I wanted my partner Liz to do all the work but she was squirming around when I pushed the scalpel in or poked it, saying how I should be a doctor which would never happen. Anyways when we opened up the earthworm, it was hard to tell where things were because everything was covered up in the black watery ooze which was the soil, although some thought it was poop. We got to learn that they are hermaphrodites which I wouldn't have guessed, thinking the females look different than males like any other animal. That they have a mouth AND an anus, unlike Cnidarians they have one way of getting things in and out! There wasn't much to see, Liz and I were far from done with dissecting the worm plus my camera phone didn't take very good pictures so we ended up giving it to the group beside us to observe it because they had cut too deep. It was a good experience and a good time even though I wouldn't do it again, I would just observe from afar knowing we have more dissecting projects to come. Here are some pictures that I took of that I was not able to label and some that I had borrowed from the internet.

Trace the digestive tract which food passes:
The digestive tract goes straight through the middle.
How can you find out whether an earthworm eats soil or not?:
All the black marks are from the scalpel touching the worms digestive tract from where the soil travels.

Which part of the earthworm serves as a brain? How are these parts connected to the rest of the  body?:
The brain is above the pharynx and is connected to the first ventral ganglion, which the brain is made up of many nerves all through cephalization. 
What is the name of the pumping organs of the earthworm?:
The pumping organ is called the Aortic Arches.

Which parts of the worm body that you saw included the excretory system?:
My picture isn't very clear but this was the closest I could get from not having a blurry picture.

Among the earthworms structural adaptations are its setae. How do you think the earthworms setae make it well adapted to its habitat?:
The setae provides traction for movement which helps anchor and controls the worm when moving around in the soil.

How is the earthworms digestive system relatively adapted for extracting relatively small amounts from large amounts of ingested soil?:
Once the soil is ingested it goes through the digestive tract, to the esophagus where it reaches the crop (stores the soil) and to the gizzard (grinds it up into smaller pieces.) 

Your dissection of the worm did not go beyond segment 32. What will you observe if you dissect the remainder of the worm to its posterior end?:
If we had continued the dissection we would have just seen more of the digestive tract, ventral nerve cord, the anus and a lot of soil. 

During mating, 2 earthworms exchange sperm. Fertilization is external and cocoons are produced from which the young eventually emerge.  
When reproduction occurs, the earthworms attach to each other where they give off sperm. Then are stored in special sacs until they are ready to be fertilized. When both the eggs and sperm are ready the clitellum secretes a sticky ring where they fertilize.