Rat DIEssection

Fresh Alcochol-drowned-rat

 When I first heard that we were dissecting rats, I was shocked.Although we had few dissection labs, I didn't think I would dissect a chordate. I mean, I can dissect worms and squids no problem, but rats are just too real and vivid for me to dissect. Anyhow, the purpose of this lab was to dissect the rat and by doing that,

understand the internal and external features of the general chordate, especially those of class mammalia. 

Nathan preparing surgeory

Last week, I arrived in class highly worried, in contrast to other dissection labs where I felt nervous and exciting. Our group got a female rat. Firstly, we observed the odd external features of the rat. The rat, being classed under mammalia, had mammary glands. 12 of them. It also had hair on its body, which is the second characteristic of the mammals. I assumed the rat had a diaphragm because throughout class, I learned that all mammals had a diaphragm, mammary glands, and hair. I also knew that these rats were viviparous, and was afraid that when I opened up the rat, I would see babies inside.  Our group started dissecting by carefully and passively cutting the rat's body. Luckily for us, there were no babies. Nathan and Alan lead the surgery, and later on, I subbed in for Alan. When we cut its body, I could finally see the rat's internal organs. The 4-chambered heart, intestines, and liver caught my attention. We proceeded on to further investigate the deepest areas of rat's anatomy, and took out the intestine. As a result, we were able to thoroughly investigate the whole internal organs of the rat's body. 

After cutting it open

Upon completion of this lab, I gained many things. Those were: improved knowledge on mammal's external and internal features and confidence in dissecting. Without this lab, I wouldn't have known that rats had 12 nipples. Despite myself being grossed out by the rat, in the end, I really enjoyed the lab. This lab was meant to be the finale of Biology 11- it simply had a huge impact on me. 

Discussion Questions:

1. Because god gave us 10 styluses; It is the most precise and controllable.

2. To differentiate between all other organs and structures. This will act as your guide line.

3. Tails are different because they are slimier and more disgusting than bodies. Other than that, it is used to keep itself stable and control its body heat

4. Vibrissae is a feeler.

5. This means that it is more developed than those of radially symmetrical organisms. Also it means, that both sides are equal when cut in half.

Discussion Questions

1. The circular muscle, sphincter, controls the passage of material

2. Small and Large intestines differ in sizes because they carry out different jobs. Large intestine absorbs water from undigested material, and small intestine absorbs nutrients as well as water.

3. The liver transforms the nutrients (breaks down) into a body-suitable nutrient.

After taking out the
intestines of the rat

4. Duodenum is a latin name for 12 finger-lengths. So it got its name by being approximately being 12 finger-legnths long.

5. The appendix is there because it digests cellulose

Discussion Questions:

Intestines of the rat

1. The membrane that cover both the wall of the cavity and the organ in contains is called the peritoneum. It holds all the organs in place.

2. The function of spleen is to remove red blood cells and to replace them with new lymphocytes

3. Diaphragm's function is to help breathing of the animal by lifting up the chest.

4. Atria and Ventricles are different. Atria holds the blood which then goes to the ventricles that contract blood and pump the blood to the lungs, and body.

5. The left ventricle is thicker because it pumps blood to the body, and is faced against the pressure of the aorta.

6.  They both are used to reproduce. They mature at the same rate.

7. Kidneys regulates the body fluid

8. The thyroid, thymus, and the adrenal glands are all part of the endocrine system. They have different jobs. Thyroid coverts iodine to thyroid hormones, thymus produces t-cells, and the adrenal glands produce hormones against stress.

***PICTURE TO BE ADDED

Cicada

Phylum: Arthropoda
Class: Insecta

Body Structure: Cicadas go through a incomplete metamorphosis. Therefore, its nymph stage and adult stage does not differ drastically. On its adult stage, the cicada have 4 wings attached to their stout bodies. The wings when fully spanned, rages about 2.5cm to 15cm. When cicada is not using it, it rests at its back along side of the body. The wings colourless, and are supported with thin and firm veins that strengthens it. Adult cicadas all have 3 pairs, or 6 legs, just like all "insecta"s. They also have large compound eyes along with three small eyes called ocelli, that are mainly used for detecting predators from above. Adult cicada's antennae are small and setae-like, and is located just under the ocelli. For the mouth part of the adult cicada, it is enclosed in a long, thin, beak-like sheath. The sheath is called labium, and it consists of 4 fine, needle-like stylets that are used for feeding.

Respiration: The air enters through the spiracle, and from there, The tracheal tubes supply oxygen by diffusion to all body tissues.

Excretion: They use malpighian tubules to remove nitrogen-containing wastes from blood, concentrate them, and then add them to undigested food before it leaves through its anus. Also, in arthropods, and in cicadas, undigested food becomes solid waste that leaves through the anus.

Feeding: Cicadas are plant eaters. They eat by piercing the surface of plants with their mouth stylets. Then, they proceed onto sucking up the sap through a tube formed by the concave surfaces of two of the stylets.
However, because of this, Cicadas may prevent the growth of trees with the amounts of sap they drink.

Movement: The Cicada has wings that span 2.5 cm - 15 cm, as I mentioned above. They are EXTREMELY bad pilots though.


Circulatory System: Cicadas have an open circulatory system. This contributes to the fact that overtime, Cicada gets darker and darker in colour. It is known that not much blood flows to Cicada's legs as they remain hollow. This is the reason why Cicada stays so long in its upside down position.

Reproduction/ Life cycle: Usually, a young Cicada takes about 1~6 years of nymph form before becoming a full grown adult form. They hatch from its egg usually underground and spend their 6 years there. Afterwards, they come outside and grows wings to officially enter its adult stage. Contrary to their 1 to 6 years of nymph stage, they can only live up to few weeks in their adult form. While an adult, all male Cicada make sound in the operculum; which attracts females.The male and female adult cicadas mate and have fertilization internally. The male dies instantly, and the female dies shortly after laying its eggs.

Other Facts: CICADAS HAVE BILATERAL SYMMETRY, JUST LIKE ANY OTHER ARTHROPODS AND COMPLICATED ORGANISMS. They have 3 germ layers: ectoderm, endoderm, and mesoderm.

Cicadas are protosomes because during their 8-cell developement stage, they are spiral and determinate, their celom formation is schizocoelous, in other words, the ceoloms are solid mass of mesoderm split to form coelom, and their moouth develops from blastopore.

Interesting Facts - Singing of Cicadas Why&How?:

Singing:
The organs that cicadas use to make sound is called the tymbal. These are pair of membranes located in the abdomen, and the Cicada contracts and reliefs the muscle in order to make sound. When they contract the muscle, the membranes come inward, producing a sound. Note that Cicadas are the loudest and the only distinct sound makers, and scientists do not know how this process makes such a loud noise.

When Cicada sing, it is usually in the hot summer afternoon; they also stand still while singing. As I mentioned before, this singing attracts female Cicadas, and females are known to not sing.

Ecological Significance: Cicadas are part of a basic food chain

Squid DIEsection

           On this Thursday, I had fun dissecting a rather familiar invertebrate; the squid. Personally, I thought I knew a lot about squids. I eat them, cook them, roast them, and even eat them raw like sushi. As it turns out, all the squids that my family was buying all had been handled; I had never seen all those inside parts in my 10 years of squid handling experience. In otherwords, I was able to meet the objectives of this lab; locating and understanding the different functions of the squid.

Through this lab, I got to examine the external and internal organs of a squid. When I first learned about the phylum Mollusca, I was shocked to see a squid as one of them – I always thought the squid had soft, slimy bodies. However, when I was dissecting the internal of the squid, I was successfully able to figure out why even “cephalopods” are considered in the phylum Mollusca and why they are coined “head-foot”. Two of the biggest traits of the phylum Mollusca are that they have shells and a muscular foot. Internally, I was able to see a squid’s pen, a hard shell like structure that helps attach the squid’s organs. Externally, I was able to spot out that the muscular foot evolved to tentacles and arms to fit more suitably to their environment. Also, I was able to clearly see the squid’s eyes that are specially developed for hunting down prey.(My grandmother always used to eat it… yuck)

This lab was really helpful to me in two major ways. First, it obviously educated me to a new level of biological experience. However, secondly, through this lab I realized that even a tasty and weird looking creature like a squid has fascinating, and an organized structure. I personally think “dissection” labs are one of the best types of lab that I have ever had. I really hope to do more in future.       

1. A squid has 2 arms, and 8 tentacles

(Credits to Alan Zhong)
2. A squid's arm and tentacles function differ.
A squid's tentacle has suckers attached to it which
captures prey, and a squid's arm makes sure the prey
cannot escape

3. The energy force of the squid is called "jet propulsion"
The squid will move away from the force. Hence "water
goes this way" and "squid goes this way"

4. There are two external features that are adaptations for squid's
predatory life. These are the Eyes of the squid and the Tentacles
and Arms of the squid. The eyes of a squid is highly developed
for spotting and for hunting prey, and the arms&tentacles of a
squid are essential for a squid as both parts are extremely
well-suited for hunting prey.

5. The two general traits of molluscs were the
Visceral Mass, and the Feet that evolved from
the normal foot of a mollusc.

1. A squid has 1 pair of gills, a total number
of two.

2. The ink sac empties into the water, which
is primarily used for disrupting, and surprising
a prey or a predator.

3. The function of a squid's pen is to hold together
the muscles of a squid. 

4. I think that the wastes exit the squid through
the squid's anus. 

Earthworm DIEsection Lab

I consider myself as a "man". However, when we were dissecting earthworms on this Friday, I was hesitant to state myself that. Before I get into details about the dissection of the worm, I'd like to say that this lab was simply amazing. Through this lab, I could vividly see, almost touch the worm parts and their organs, and this helped me understand the whole Phylum Annelida to a whole new level. For example, now I have a clear idea what a true coelom is. Before, I had to just had to nod my head with the vague description given: "body cavity which allow them to have true organ systems and muscular layers". Now I know that earthworms have true coelom, just like humans. Another great thing about this lab was, I got to see not only the outside parts of the worm, but see all the inside and guts of the worms. The digestive tube of the worm looked like a long trail of black ink. The digestive system of the worm was interesting to look at because not only the tube connects the mouth and the anus, it also was very dirt-like. The hearts, however, looked completely different and, out of the ordinary. In fact, there were five of them. The heart, otherwise known as the aortic arches, pump blood through the worm's body.

In retrospect, I understand why this lab was done - to observe how an earthworm's structures of earthworm anatomy. At that time, I was busy freaking out and having a great time by observing a worm's internal organs. In the lab, I followed the instructions on the hand-out carefully, and proceeded to dissect the whole worm. However, I was pretty messy with the surgery; I am pretty sure I squished an organ here and there. Overall, I think this lab has really stepped up my knowledge in the Phylum Annelida. I'd give it 10/10.

Responses

1. The name of the pumping organs of an earthworm is
called the "Aortic Arches" or, the hearts

2. The food passes through the Mouth, pharynx, esophagus,
crop, gizzard, and intestine. (in order)

3. The parts that serve as an earthworm's brain are the ventral nerve cord,
because its brain and the cords are attached together, and travels
throughout the length of the worm.

4. The parts of the worm's body that were included in the
excretory system, that I got to observe was the Nephridia
and the anus (not labelled on photo). The anus is located at the opposite end of the head of the worm. 

5. One can conclude that a particular earthworm eats soil
by observing the black intestine of the worm.

CREDIT: http://www.angelfire.com/ny4/sci7/Setae.jpg
6. An earthworm's seatae make it well adapted to its habitat by  helping
earthworms anchor into the soil while burrowing, digging, and moving
around in the dirt. Without this adaptation, the worms will have much
harder time trying to squiggle. (LOCOMOTION)

CREDIT: #2 OF MY QUESTION
7. The earthworm's digestive system is adapted for extracting relatively small
amounts of food from large amounts of ingested soil by digesting the dirt
through its long intestine. Also, the gizzard breaks the food down, completing
an unending "digestive cycle"

8. The reason that our dissection did not go beyond segment 32 is because
it is disgusting, and all the juicy stuff is located at the anterior part of the worm.
As we dissect down, we will possibly able to spot the liquid substances that 
the worm ate.

Earthworms fertilize by sexually mating. During this process,  two
worms line up opposite to one another, and exchange sperm. The Citellium
forms a slime tube. As the worm moves through it, it will pick up female pore,
eggs. The tube will continue to move down the earthworm and pass over
the male pore called the spermatheca which has the stored sperm
called the spermatozoa. Finally, the slime tube will close out, and forms an
egg cocoon that will be placed in the soil. 

Zoology WEBQUEST

Phylum: Platyhelminthes
Genus: Pseudoceros
Species: cf. dimidiatus

This worm was spotted in Batangas, Philippines, May, 2001, 
about 10m deep in to the ocean. This worm is also known as
"divided flatworm". Its colours reminds me of the dark knight



Phylum: Platyhelminthes
Genus: Eurylepta
Species: sp.

This odd-looking worm was found near Nelson Bay, New South Wales,
 Australia. It grows up to about 30mm in length. This species is quite rare,
and is hard to find in the ocean.



Phylum: Platyhelminthes
Genus: Prostheceraeus
Species: giesbrechtii

This outstanding-coloured worm is otherwise known as
"roseus". It's quite beautiful. However, I could not find
much information about this flatworm.

Aquarium

I was 4 years old when I first went to the aquarium. Personally, I don’t like animals – especially flying, swimming ones. I was crying in every single photo my parents took in the aquarium. I was scared that those scary sharks and fish would come out and bite me. For these reasons, this trip seemed to be not as exciting for me. However, the merit of getting to skip all of my classes for free while hanging out with friends was too great of a chance to miss, so I decided to come.

However, I was depressed by the first sight of the aquarium. It had no “presence”, in contrast to the Korean aquarium I have visited before, which had overwhelming amounts of presence, and seemed ginormous (13 years ago point of view). The series of depression came no more as I explored and ventured my ways into the aquarium. From start to finish, I was more or less hugely entertained by countless invertebrates, vertebrates that were kept in the tank. The aquarium has offered me many reflections on how every small organism plays a big role in its own environment, and also how important it is to not conserve the environment the way it is. Small anemones are essential for some fish and coral reef formation. Importance of a small fish called Arctic Cod cannot be overly emphasized due to its relationship with other fish, seabirds, seals and whales that eat it. Even small worms have its own job of cleaning the ocean floor. 

After a tiresome, but fun exploration of the aquarium, I took the advice from Ms.Iannone by going to the afternoon marine lab. The first station was very boring – I slept through the half of it. I just did not buy into carefully observing sea snails. Nevertheless, I felt kind of lucky that I got moved into a different group than my friend’s, because my instructor was really informative and passionate. Although I hated the first part of my lab, I was delighted that I could touch super cool fish on the next station. Our instructor told us many things including how sea stars (not fish she over exaggerated how “seastars” aren’t star“fish”) can grow up to 30 something legs, how anemones deadly stings do not affect human at all, and a symbiotic relationship of hermit crabs and anemones; hermit crabs put sea anemones on their shells to scare organisms, and anemones benefits by getting to digest fragments of hermit crab’s meals. I touched anemones, clams, and starfish. I could not dare to touch sea cucumbers and crabs, which I hugely regret.

            

In the aquarium, I could notice lots of cnidarians and poriferans in the aquarium. Jellyfish, caught my attention as I came into the aquarium. I reminded to my fellow classmates that these were THE cnidarians we have learned in class. I could just identify straight away that the jellyfish was a schyphozoa, because it was motile, tentacles faced down, and it looked like the jellyfish (if not the same) in the notes we took. There were at least one kind of polyps and sponges in every fish tank – including the “burrowing anemone” which was misleading because they do not actually burrow, but is sessile just like any other polyps. There is an old Korean saying: “You see as much as you know”. If only I learned about flatworms prior to this trip, I would have seen them, but I saw none. However, now that I have learned about jellyfish, anemones and sponges, I finally know what spongebob and its background (pink and green flowers) truly represent.

         

I think the whole purpose of this trip was to get me and our classmates prior knowledge on our next learning materials. I found it very helpful this way, since I am very excited to learn about marine creatures than, ever. I enjoyed this trip, and was one of the best field trip I have been into.

AQUARIUM SCAVENGER HUNT

1. "Nemo" and its eggs depend on sea anemones for protection.
-description from aquarium itself/ picture not by me.

2/3. Otters spend much time cleaning their coats
because, by cleaning Fur, it insulates by trapping
tiny air bubbles and keeping a layer of warm air
between the water and skin.
Before 1900's, we could find a continuous pop of
sea otters extending from Alaska to California
- Aquarium description

4. These anemones are far away from the sea
otters tank. I couldn't find any anemones near
sea otters at all. However, I found this beautiful
anemones in Vancouver Aquarium, which colours
are distorted by colour of blue light.

5. My favourite invertebrate was Japanese
Pacific Jellies. Mainly because I knew it was
cnidairian - Schyphozoa that we got to learn in class.

6. A lady is feeding a Quila Beluga. A scientific
name for the beluga is "Delphinapterus leucas"
There are two, Quila and aurora

7. I found spotted seahorses, but not potbelly seahorses in the aquarium.
 Nevertheless, potbelly seahorses uses fins to swim and could move
50 times a second, but they are not fast.
-picture not taken by me

8. uh… for me belugas looked weird enough to look like a human nerve system.

9. Starry flounder is flat – much like the stingray/ it is less spotted
by the predators. It also camouflages well with its environment.
-picture not taken by me

10. These are moon jellies. Moon jellies slow
jet-propulsion with their tentacles and their
bells. They attract plankton by colenterons
that lets plankton stick onto their tentacles.

11. I didn’t get to see the octopus. However, Pacific octopus’
white suction cups serve as their utensils, they hold and
 tightening their prey. They are known as the nature’s best
 predators as it is very good at disguising itself.
-picture not taken by me

12. I also didn’t get to see the sea lions. Adult Steller sea lions
 eat a wide variety of fishes, including Pacific herring, pollock, salmon, cod,
and rockfishes. They also eat octopus and some squids. On average,
an adult Steller sea lion eats about six percent of its body weight each day.
-picture not taken by me

13/14. Yacare Caimans: They are from
South America. Their colours are dark black
which camouflages to its environment. It also
did not move for a whole 5 minutes when I was
observing it.
- description from aquarium

15. Arapaima is the largest fish in the aquarium
with an astounding record of 3m!
-description from aquarium

16. Tambaqui has strong enough teeth to crush nuts and seeds
 and actually live off from it.
-picture not taken by me/ description from aquarium

17. When people are removing hook from a piranha’s mouth is
when the piranha becomes a biggest threat to humans.
-picture not taken by me/ description from aquarium

18. sharks are too fast for me// They have no
bones, but instead they have cartilages. 

19. Turtles, stingray, Laced Moray Snapper, Butterflyfish, angelfish, and sergeant were all found in the

shark tank.

21. Archerfish finds their prey by ambushing their prey – which are
mainly insects. They shoot a stream of water with such force
 that knocks the insect unconscious (or not), which then they fall off into water.
-picture not taken by me

20. The Giant Red Sea Urchin has its spiky spines to protect itself from various predators. Its scientific name is “Strongylocentrotus franciscanus”
-picture not taken by me

22. The scientific name of the Sea Turtle is “Chelonia mydas” otherwise known as Green Sea Turtle.
-picture not taken by me