Dissection Lab

Starfish Dissection

The Plycocic  Checa is the digestive glands that are found running down the arms of the starfish. they help to break down the food it eats.

water enters the starfish through the madreporite located next to the central disk.

the water that has entered the ring canal and then flows through the rest of the body through the lateral canal.

The mouth is found on the bottom of the starfish and so are the tube feet. the tube feet allow the starfish to move, by pushing water into the feet and filling them up which then makes it so it can move around.

Incision guide.

at one  cut off the tip.

at 2 cut down the center of the stars arm

at 3 cut out the circular disk

Earthworm Dissection

External Anatomy:

The earthworm appears very simple and plain to the naked eye, but when looked at up close, it’s very detailed and intricate. When looked at from a distance, the first thing noticed on the body is the clitellum. It is almost like a swollen part of the worm on it’s dorsal surface. The clitellum is responsible for secreting a mucus sheath which surrounds the worm while mating and creates a cocoon for the fertilized eggs. The anterior portion is a lot more flattened which allows it to drag itself more efficiently. On the dorsal side of the worm there are many bristle like spines called setae which almost allow the worm to carve through the ground and dirt. Extending from the clitellum we also have pores which can act as male or female genitalia.

Internal Anatomy:

Many would think that the earthworm is nothing special and just a long tube like simple creature. From the outside it appears to be true, but when looking at the internal anatomy it’s the complete opposite. Digestion begins in the oral cavity with the mouth and buccal cavity. The esophagus follows the pharynx and leads in a crop which is a reserve stomach. Posterior to the crop is the gizzard, which is a muscular organ responsible for churning the soil and ground ingested by the worm. The large intestine follows the gizzard in which the majority of digestion and absorptionccur. Whatever is not digested in excreted through the anus.

Dissection:                  

Frog Dissection

1. Cut along the sides of frog's mouth in order to better see inside of frogs mouth

2. Turn the frog over and cut the frog along the red lines and use the pins to hold the skin of frog down

Frogs are amphibians and live on land and in the water. The frog has 2 external nares that allow it to breathe. The frog's tympani are its eardrums. It also has 2 eyes on the side of its face and each eye has 3 eyelids.

Inside the mouth there are vomerine teeth and maxillary teeth that help frogs capture prey.

Inside of the frog there is the stomach, which is where food is digested and broken down. The small intestine is the location where the nutrients from food are absorbed. The frog's liver produces bile which is used during the digestion process. The function of the pancreas is to help digestion by producing insulin. In a female frog, the ovary produces eggs that are later fertilized by a male frog's sperm.

Clam

External Anatomy:

A clam is surrounded by two hard shells made of calcium. the hinge ligament allows the clam to open and close. It is tough, but also pliable, in order to open as much as it needs. On top of the hinge the bump, called the umbo, is the oldest section of the clam. As the clam grows, it produces growth rings all over the shell.

Internal Anatomy:

The adductor muscles are used to close the shell in order for the clam to avoid predators. The muscular foot can reach outside of the clam and allow it to bury itself whenever needed. Without the mantle, the clam would not have protection. The mantle secretes calcium carbonate which is what forms the hard outer shell. On the inside there are also gills which serve a vital part. The gills allow the clam to obtain oxygen, and get food. The cillia on the gills create current which moves the water through the clam body. Also located inside are digestive glands which aid in digestion and gonads which play a major role in reproduction.

pGLO Lab

Purpose: The purpose of this lab was to perform genetic transformation by moving genes from one organism to another with the help of a plasmid. By doing this, we could make incorporate pGLO into cells and make them glow.

Intro: Genes can be spliced into a cell in order to alter the makeup of the cell. In our lab we spliced a "pglo" gene into EColi bacteria in order to make it resistant to ampicillin. This the presence of the pglo gene will allow the EColi to glow under an Ultra violet light. Without the pglo the bacteria will die once introduced with ampicillin. The activator for the pglo gene is arabonose sugar, so when arabonose is present the bacteria will grow more.

Methods: First we transfered 250 ul of CaCl2 into test tubes labeled +pGLO and -pGLO and then placed them in ice.

Then we moved bacteria from the starter plate into the tubes by scraping it from the plate with a loop and swirling it into the solution as shown in the picture. And then we placed the tubes back in ice.

Then pGLO plasmid DNA was added to the +pGLO tube but no the -pGLO tube. The test tubes were placed in ice for 10 minutes before being placed in a hot water bath for 50 seconds to heat shock them.

The tubes were placed back in ice for 2 minutes and then removed. Then 250 ul of LB nutrient broth was added to both tubes and they were mixed.

 Finally 100 ul of the tubes solution were added to their respective plates, +pGLO LB/amp, +pGLO LB/amp/ara, -pGLO LB/amp, -pGLO LB.

The suspension was spread evenly on the plates and then they were left alone for a day.

Data:

This is the picture of the base bacteria that we took the sample from to spread it to all of our plates

(from left to right top to bottom) ampicillin was added to the plate but the ere was pglo so it was able to resist and survive, thus showing some growth. then there is lots of growth on the LB because there was just regular conditions for the bacteria to grow in. next there was marginally more growth in the amp/ara because there was the activator arabinose which  makes the pglo more active. and because of the pglo the ampicillen did not kill the bacteria. finally there is nothing in the last tray because the bacteria did not have the pglo gene in order to make it resistant to ampicillin so it died.

 picture showing that none of the other trays but the LB/AMP/ARA is glowing because it has the activator to make the pglo glow.

 the arabonose dish before UV                                     the arabinose dish after UV

Discussion: In our base group with just the EColi gene there was massive amounts of growth, and the entire dish was full. Where in the plain EColi gene introduced with ampicillin there was nothing in the tray because all the bacteria was killed. Then in the pglo enhanced EColi gene there was actually growth on the ampicillin tray, but there was not that much. This is because not all of the bacteria cells become resistant to the ampicillin. So the ones that weren't resistant died. Then finally the pglo bacteria introduced to the ampicillin and arabonose sugar was able to grow more because pglo becomes active when arabonose is present so it grew more than without the arabonose. But not nearly as much as the base dish.

Conclusion: The objective and process of this lab was to move genes from one organism to another by using the help of a plasmid. The pGlo plasmid we used had a gene which was encoded for GFP (green fluorescent protein), was altered with both arabinose or ampicillin. Each of the four dishes in which the plasmid was placed had a different component as explained above. The dish labeled with LB/ARA/AMP was able to glow in the dark which gave us a clear result on the test. The others did not, as predicted.