Fish (Perch) Dissection

Background Information
Where is it found?
The perch is a freshwater fish that is commonly found throughout the British Isles and much of Europe, South Africa, and Asia.
What does it eat?
The perch's diet consists of worms, small fish, and larvae.
How does it breath?
The perch takes in oxygen through its gills which are located on either side of its head. Water enters through its mouth and travels through blood vessels to the gills which filters out carbon dioxide.
Fun fact:
When threatened the perch raises their spiny fins as a defense against being eaten.

Gills- used for breathing 

Swim bladder- contributes to fish's ability to control buoyancy without wasting energy

Liver- acts as a food reserve 

Stomach- digests food

Heart- pumps blood to other parts of body

Use dissecting pins to secure the fish to the dissecting pan. Use scissors to make the cuts through skin and muscle. After making the cuts, carefully lift off the flap of skin and muscle to expose the internal organs in the body cavity.

Grass Frog Dissection

Where is it found?
Grass frogs are found throughout most of North America including Southeastern Virginia, eastern North Carolina, eastern South Carolina, and southern Georgia. The grass frog can be found in meadows, gardens and woodland, and prefer shallow areas of water.
What does it eat?
Frogs tend to prey on insects, worms, snails, and slugs.
How does it breathe?
The grass frog can breathe through its skin.  Because of this, the frog is able to hibernate for months.
Fun fact:
When a male frog successfully attracts a female companion, it will wrap its forelimbs around the female in an embrace.

Liver- secretes bile and processes digested food

Stomach- stores food and begins digestion

Large intestines- stores undigested food

Gallbladder- sac that stores bile made in the liver

Turn the frog on its back and pin down the legs. Cut the hinges of the mouth and open it wide. Use the diagram below to locate and identify the structures inside the mouth. Use a probe to help find each part: the vomerine teeth, the maxillary teeth, theinternal nares, the tongue, the openings to the Eustachian tubes, the esophagus, the pharynx, and the slit-like glottis.

Starfish Dissection

Where is it found?

Starfish are found in saltwater bodies all around the world.
What does it eat?
A starfish's diet usually consists of clams, oysters, sand dollars and mussels.
How does it breathe?
Starfish breathe through their feet since they are made of a thin tissue in which gasses can pass through easily.
Fun fact:
A starfish's mouth is located on the underside of its body while its anus is located on the upper side of its body.

Spines- to provide protection from predators

Ceolomic cavity- holds organs in place

Center dish- center of body containing mouth 

Inside each arm, locate two long digestive glands called the pyloric caeca. These make enzymes to digest food in the stomach. Cut a circular flap of skin from the central disc. (You will have to also cut around the madreporite in order to remove this flap.) Observe the stomach under the central disc. Remove the pyloric caeca from the dissected ray. Find the gonads (testes or ovaries) underneath. These may be small if the starfish is NOT in breeding season. Remove these to see the rest of the water vascular system. Cut off the tip of a ray to observe the parts of the tube feet. Find the zipper-like ridge that extends the length of the ray. The tube feet are attached to these. Locate the bulb-like top of a tube foot called the ampulla. This sac works like the top of an eyedropper to create suction. The bottom of the tube foot is a sucker. Embedded in the soft body wall are skeletal plates called ossicles.

Clam Dissection

'Where is it found?
Clams are found in the coastal saltwater bodies and in shallow freshwater lakes and streams.
What does it eat?
Clams eat plankton.
How does it breathe?
Clam breathe through bivalves that filter their respiration water. Their gills remove oxygen and food particles from the water
Fun fact:
Clams have no eyes, ears, or noses, so they cannot see, hear, or smell.

Gills- used to breathe and move food through body

Foot- can stick out of shell and be used to burrow

Unblock- oldest section of shell

 Mantle- part that forms shell, secretes calcium carbonate 

Cardinal teeth- help shell close properly 

Turn the clam with its dorsal side down and insert a screwdriver between the ventral edges of the valves. Carefully work the tip of the screwdriver between the valves so you do not jab your hand. Turn the screwdriver so that the valves are about a centimeter apart. Leave the tip of the screwdriver between the valves and place the clam in the pan with the left valve up. Locate the adductor muscles. With your blade pointing toward the dorsal edge, slide your scalpel between the upper valve & the top tissue layer. Cut down through the anterior adductor muscle, cutting as close to the shell as possible.

Grasshopper Dissection

"Where is it found?
It is found in grassy areas worldwide.
What does it eat?
Grasshoppers are herbivores that feed on  a variety of plants.
How does it breathe?
Grasshoppers along with other insects use tracheal breathing.
They exchange oxygen and carbon dioxide between their tissues and the air through a system of tubes.
Fun fact:
Grasshoppers have ears on their abdomen.

Hind leg- 

Abdomen- tail area of a grasshopper (contains heart, digestive system, reproductive organs)

Antennae- sense and touch environment

Hind legs- used to jump 

Walking legs- used to walk 

Thorax- mid area, where legs and wings attach

Wings- used for flying

Eye- made up of hexagonal lenses

Using forceps, remove one of the walking legs and identify these parts --- the coxa connects the femur (the thickest part of the leg) to the grasshopper's body; a slender, spiny tibia connects the femur to the tarsal segments (lowest part of the leg). Raise both pairs of wings and locate the first abdominal segment.

Crawfish Dissection

Where is it found?
Crayfish can be found in any body of freshwater including streams, rivers, lakes, and ponds.
What does it eat?
Crayfish eat fish, shrimp, water plants, worms, insects, snails, plankton, and even dead plants and animals.
How does it breathe?
Crayfish breathe through Internal gills.
Fun fact:
Over 350 species of the 500 crayfish species of the world live in the United States.

Gills- used to breathe under water

Dorsal abdominal artery- central artery coming from heart 

Cardiac stomach- receives food from esophagus for storage

Digestive glands- secrete enzymes for digestion of food

Using one hand to hold the crayfish dorsal side up in the dissecting tray, use scissors to carefully cut through the back of the carapace along the dissection line. Cut along the indentations that separate the thoracic portion of the carapace into three regions. Start the cut at the posterior edges of the carapace, and extend it along both sides in the cephalic region.

Worm Dissection

I'm Where is it found?
Worms are commonly found living in soil.
What does it eat?
Worms get their nutrients from things in the soil such as decaying matter and leaves.
How does it breathe?
Worms must stay moist in order to breathe since they absorb oxygen through mucous on their skin.
Fun fact:
Earthworms are both male and female because they produce both egg and sperm.

Anus- excretes waste

Clitellum- excretes sac that holds eggs

Semenal vesicle- hollow organs that hold semen

Pharynx- muscle that sucks in food

Crop- holds food

Gizzard- breaks down the food

Septa- structural segments

Dorsal blood vessel- main blood vessel towards the rear of worms body 

Position your preserved earthworm dorsal side up and pin it down through the first segment and then again further back behind the clitellum.  Cut a slit in the dorsal surface near the posterior pin.  Using fine scissors extend the cut forward to the first segment.  Be careful not to cut too deep.  Starting at the first segment, cut the septa (thin membranes) that internally divide the segments, so the skin can be laid flat.  Use additional pins to hold the integument open and expose the organs.  Continue to lay the skin back until you have uncovered a centimeter or so of the intestine.

Pglo Transformation Lab

Purpose: 

The purpose of this lab is to observe bacterial growth under different conditions and in different environments. 

Introduction:

Genetic transformation is the process of genetic material that is carried by a cell being altered by the incorporation of foreign DNA into its genome. In this experiment, bacteria is going to be transformed by the insertion of a gene that causes the bacteria to glow (pGLO). With this gene, the bacteria should glow green under ultra violet light. Not only does this genetic transformation allow for the bacteria to glow, the pGLO is also resistant to antibiotics. The green fluorescent protein gets switched on by the sugar arabinose. This explains why the bacteria should only glow on plates that contain arabinose on them, but will appear normal on plates without it. 

Methods

Discussion

Gene transformation is when a cell takes in a foreign gene and expresses new DNA. In this lab, we infused the Green Fluorescent Protein (GFP) from a jelly fish along with an antibiotic resistant gene into the DNA of E. coli with the help of a plasmid. Plasmids are circular DNA that usually contain genes for one or more traits. We used the pGLO plasmid which contained the gene for GFP and a gene for resistance to the antibiotic ampicillin as mentioned above. In this lab we had 4 dishes. The first was our control group which held bacteria only provided with LB (food). This plate had growth because it was given food, however the bacteria didn't glow since it was not exposed to the pglo gene. The second plate was al so a control group. It had LB and ampicillin which is an antibiotic (kills bacteria). Therefore there was no growth on this plate because the genes were not exposed to the antibiotic resistant gene. The third plate had LB, and ampicillin, however it was exposed to the plasmid which contained the antibiotic resistant gene. So there was growth, but less than the LB control plate because only some of the bacteria took in the antibiotic gene into their DNA. The last plate had LB, ampicillin, and the pglo gene so there was growth because it had the antibiotic resistant gene, and the bacteria glowed in the dark. Since it took up the pGlo gene.

Conclusion
Overall, we learned how we can mash two different types of DNA together. It was cool to see that just through a simple experiment we could make a bacteria become antibiotic resistant and glow in the dark. Gene transformation is being used recently by scientists to experiment putting specific genes in bacteria to treat certain diseases. It was cool to think that we could do an experiment that professionals are using now to advance science and medicine. 

Restriction Mapping of Plasmid DNA

Purpose:
The purpose of this lab was to experiment with the usage of restriction enzymes on plasmid DNA using gel electrophoresis.

Introduction:
A restriction map is a visual of DNA with known restriction sites of that given sequence. A restriction map requires the use of restriction enzymes, which are enzymes that chop up a DNA molecule at a specific site. These DNA fragments are then separated by argos gel electrophoresis.  The distance between restriction enzymes can be found by comparing the patterns of the fragments. This process can be used to figure out information about the structure of an unknown piece of DNA. The fragments are compared to a lane of DNA markers which works a a size comparison chart. In this way the size of a DNA segment (number of base pairs) can be estimated.

Procedure: 

1) Carefully insert the buffer unto the gel's well by squeezing the pipette. Use the following table to make sure each buffer is in its correct well.

2) Bring the gel, which should look like the one below, to the electrophoresis area made by your teacher and place into the solution. 

3) The next day, take your gel out of the solution in the electrophoresis chamber and place it on a light box. It may help to mark the visible bands with some kind of marker to make them easier to see.

Discussion: 

PstI ad bands at 700 and 4700. PstI/ SstI had bands at 700, 2200, and 2500. PstI/ HpaI had bands at 700, 500, and 4200. PstI/ SstI/ HpaI had bands at 700, 1300, and 3000. Each digest added up to 5400 and had a band at 700. Because HpaI only has two fragments it must be circular. If the DNA were linear, there would be three different fragments with two different cites. There is only one PstI site because we know the HpaI has two cites already and there are only three fragments of DNA in the sample PstI/ HpaI. With circular DNA each site produces one fragment. We know SstI only has one site for the same reasoning mentioned before. Based on the position of the fragments on the gel, the 700 base pair fragment of HpaI is  unaffected by the two other enzymes. There is no fragment that appears only in the HpaI/PstI/SspI digest. This means that the  enzymes of HpaI, PstI, and SspI spliced the DNA in their respective locations/codes. Because  there are no other fragments present, HpaI, PstI, and SspI were the only restriction enzymes  used to digest this enzyme. 

Conclusion:

The purpose if this lab was to find out the number of cut sites present in the DNA sequence for each restriction enzyme and the position of the cuts relative to one another. We were successful in achieving a satisfactory result through the use careful observations and calculations. We were able to font the number and locations of all of the cut sites.

How to Extract DNA from a Strawberry

How does it work?
Strawberries have more DNA than any other fruit with 8 pairs in each chromosome. To extract the DNA, each of the solutions used in the experiment plays a part. The soap dissolves the cell membrane, which frees the chromosomes from the nuclear membrane. The salt is added to break up the nucleotides in the DNA sequence. Finally, DNA is not soluble in alcohol because it is polar, and even less so when the alcohol is chilled.

Materials-

A strawberry

A plastic bag

10 ml of soapy salt water

100% alcohol solution

Pipett

A coffee filter

A clear test tube

Procedure

1) Rip off the green part of the strawberry

2) Put strawberry in plastic bag and mush up until pulped

3) Add 10 ml of the soapy solution to the bag, seal, and then continue to squish some more. 

4) Put cone into test tube, and put coffee filter into the cone

5) Slowly pour strawberry gunk into coffee filter

6) Allow the strawberry juice to filter through the coffee filter, it will take a few minutes

7) Add 2 ml of cold 100% alcohol to the strawberry juice

8) Watch for a minute and the line between the red juice and the clear solution will become foggy.

9) Put stirrir into foggy area and twirl

10) Pull out the stirrer, see that snot looking stuff? That's DNA!

Mitosis Lab

Mitosis:

http://youtu.be/8uEa7NOwF_I

Cell Communication Lab

Purpose

The purpose of this lab was to investigate cell signaling between two strains of yeast- a-type and alpha-type. We observed the mating interactions between the two. 

Introduction

Cell-to-cell communication, or cell signaling is an important function of cells. It occurs within multicellular organisms and between unicellular organisms. Cells can communicate with each other a few different ways, although the most popular way is via chemical signals. Yeast, also known to the science world as Saccharmoyces cerevisiae, has two mating types as mentioned earlier. The two different types communicate with each other through signal transduction pathways via secreted factors. A signal transduction pathway is a series of steps in which a message received at the cells surface is amplified through transduction which then triggers a response. In yeast cells, a-type cells have receptors that receive chemical signals from alpha-type cells. Alpha-type cells also have receptors that receive chemical signals from a-type cells. That way, when they secrete their own chemical factor, the opposite type is able to receive it. Once the two yeast cells receive the signaling factor from the other type, they begin to change their cytoskeleton in order to "grow" toward their mate. This elongation of the cell is called a shmoo. 

Yeasts can reproduce sexually and asexually. In asexual reproduction, also known as cell division, both the a-type cells and alpha-type cells bud in order to produce daughter cells, or haploids. In yeast, the haploid cell can turn from an asexually reproducing cell to a gamete, or sex cell. The yeasts then stop dividing and grow into their gamete shmoo form. the yeast begin to grow toward their partner and fuse together. When the two types come together, they form a diploid zygote. 

We used a toothpick to pick up a colony of each type of subcultures of yeast and put them into their designated culture tube filled with 2mL of sterile water.

We used a transfer pipet to transfer 5 drops of yeast suspensions onto their designated plates.

Data:

Discussion
In this lab, cell communication among yeast cells were observed. There were many differences observed between the alpha type and a type strains. In the alpha-type strains, there were more budding haploid cells than in the a-type. When looking at the graphs of both the cultures, we saw that the two had several similarities in the amount of cells between the a type and alpha type cultures. The outcome showed that more budding haploid cells were seen in the alpha type than in the a type. In the alpha type, there was a much bigger percentage of budding haploid cells (12.5%) than in the a type (5%). However, when looking at the graphs for the single haploid cells, the alpha type had a lower percentage than the a type. (87.5% versus 95 %) When observing the mixed culture, which was the alpha types cells over the a type cells, we expected to see lots of budding haploid cells from the a type, and also lots of single haploid cells due to the high percentages that both the alpha type and a type had when discussing the percentage total of single haploid cells. The hypothesis was correct. When looking at the mixed culture under the microscope, it was the most abundant amount of cells observed from the three types we had looked at. Yeast cells most likely commnicate using both direct contact and pheromones. The pheremones sent help yeast spot that there is a potential mate near them, which they grow towards and then create a shmoo. Then the cellular response reacts to turn the cell into a sex cell. Direct contact signaling allows the shmoos to send a signal to create a baby (zygote).

Conclusion
In this lab, the purpose was to observe cell signaling in three different types of yeast. Looking back at the results of the expirament, it appears that the alpha type yeast has more of a mating signal released than the a-type cells. This is concluded due to the much higher percentage of budding haploid cells than type a had. Our mixed culture had the most asexual reproduction activity, which shows that the different types of yeast can communicate with eachother using direct contact and pheremones.

Photosynthesis/Light Reaction Lab

Purpose

The purpose of this lab was to prove that light and chloroplasts are required for the light reactions of photosynthesis to occur.

Introduction

Photosynthesis is a way for plants to make their own food using direct sunlight. Photosynthesis occurs in plants, algae, certain other protists, and some prokaryotes. Leaves are the major locations of photosynthesis; where chloroplasts are located. In order for plants to produce sugar and release oxygen, they must first go through the light reactions. Chloroplasts split water into hydrogen and oxygen, incorporating the electrons of hydrogen. Light is then absorbed and the energy is used to drive electrons from water to generate NADPH, a stored sugar. When the electrons are excited, they burst upward and are caught by an electron accepter and then slowly released down via the electron transport chain. It is important to understand the job of the electron acceptor. DPIP can also be used instead of NADP. Every time the electrons in the chloroplast become excited, they will reduce DPIP. This will cause DPIP to change from blue to colorless. 

Methods 

Pipette 5mL of 100% dye solution into the 1st test tube, and pipette 2.5 mL of distilled water into the remaining 5 test tubes. 

Then transfer 2.5 mL of dye to the 2nd test tube and mix well. 

Transfer 2.5 mL of solution from the 2nd rest tube into the 3rd test tube and continue the process for the remaining test tubes. 

We filled a cuvette with solution from test tube 1 and read the Abs. and %T. We continued the same thing for the rest of the text tubes.

Graphs and Data

Discussion

In this lab, light and chloroplasts are proven to be needed for light reactions in photosynthesis. DPIP is used instead of NADP, which is the electron accepter in this experiment. When the electrons become excited, they will reduce the DPIP supply. These electrons come from the breaking down of light energy and water. The reduction of the DPIP supply will cause the solution to change from blue to clear. Due to the DPIP reduction, light transmittance is given off. This can be measured using a spectrophotometer, which measures the percentage of light transmittance. When the DPIP is placed in darkness, there is no reduction in it because the electrons cannot be excited because they do not have any light to excite the electrons. When the chloroplasts were boiled, it denatured the protein molecules, which also stopped reduction in the DPIP. There was a difference in percent transmittance of the unboiled chloroplasts that were in the light and the dark. This is because in the dark cuvette, there was no light, which meant that there was no light energy and therefore no breaking down of light and water which meant that the electrons could  not be excited. In the lighted cuvette, there was light energy, which aloud breaking down of light and water and therefore there were excited electrons.

Conclusion

The experiment preformed showed that chloroplasts and light are necessities for light reactions in the photosynthesis process. All in all, the outcome of the data proved this point true. It showed all factors of boiling, denaturing, and darkness, which did not allow light reactions to occur.





Cell Respiration Lab

Purpose

The purpose of this lab is to measure the amount of carbon dioxide released by cellular respiration by marbles, non-germinated peas, germinated peas, and germinated peas at a cool temperature.  

Introduction

Cell respiration is the process of oxidizing food molecules, like glucose, to carbon dioxide and water. It is represented by the equation: C₆H₁₂O₆ + 6O₂ + 6H₂O → 12H₂O + 6 CO_{2.  In cell respiration, chemical energy from "food" molecules is released and partially captured in the form of ATP. Carbohydrates, fats, and proteins can all be used as fuel for cell respiration, however glucose is the most common. Cells take the carbohydrate into their cytoplasm, and through a complex series of metabolic processes, they break down the carbohydrate and release energy in the form of ATP. When cells to go through cell respiration, they take in oxygen and release carbon dioxide.} 

First we put 25 marbles into the respiration chamber.

        

Then we put 25 non-germinating peas in the respiration chamber and recorded the amount of CO_{2 produced in 10 minutes.}

We then did the same process but with germinating peas.

We soaked the germinating peas in ice water for 5 minutes.

We blotted them dry and put them into the respiration chamber again.

Lastly, we tested the cold germinating peas in the respiration chamber for 10 minutes again.

Data:

Graphs:

Discussion

In this experiment, marbles, non-germinating peas, and germinating peas at different temperatures were tested for their particular rates of cell respiration. In testing the non-germinating peas in contrast to the germinating peas, data showed that germination greatly accelerated the rate of cell respiration. This shows a greater rate of metabolic activity in germinating peas versus non-germinating peas. The non-germinating peas showed very little activity, with only about .02 for the rate of respiration. When testing the peas dunked in cold water versus the peas that were at room temperature, the warmer peas showed an increase in respiration in contrast to the cold peas. The germinating peas respirate more than the dormant peas because the pea needs energy for the growth that is happening, something that is not needed in the dormant pea.  

Conclusion

This lab presents the different rates of respiration based on different organisms. It was found that

germinating peas respirate at a higher level than dormant peas.