Earthworm Dissection

Earthworms can live in tress, in bark, under rocks, along the river, springs and ponds, they prefer to live in the earth’s rich soil. They get their nutrition from things in the soil such as decaying roots and leaves. Earthworms don’t have lungs, but they breathe through their skin.  

Fun Facts

Earthworms are androgynous, producing both eggs and sperm.

Function of external structures

• clitellum - produces mucous slime during mating
• mouth- where the food goes in
• anus- releases undigested material
• male genital pore- opening where sperm from that worm is released during mating
• setae- bristle-like structures that help the worm grip surfaces and to move
• Prostomium- is a small projection that hangs over the mouth
• female genital pore- releases eggs
• sperm groove- Carries sperm from male genital pore to clitellum
• seminal receptacles- stores sperm received from other worms
• septum- Divides coelom into compartments
• segment- contract during movement
  
  

  

  
  

  

  
  
  
  
  

Function of internal structures

• pharynx- sucks in food
• gizzard - breaks down and grinds the food
• crop-  stores food
• esophagus-  food goes through here before it goes to the crop and after the pharynx
• intestine- food is broken down and absorbed by the blood
• ventral nerve cord- Relays messages between brain and body
• ganglia( brian)- masses of tissue containing many nerve cells
• ventral blood vessel- Transports blood to posterior end of body
• Dorsal blood vessel- Transports blood to anterior end of body
• septa- dividing wall between segments
• nephrida- expel excess water and metabolic waste from the blood
• testes-produces sperm for fertilization
• ovaries- where eggs are laid and stored until they mature
• buccal cavity - Holds for food and opens to Pharynx
• septum- Divides coelom into compartments
• seminal receptacles- stores sperm received from other worms
• central nerve cord-  helps the worm move and feel
• pseudohearts- pumps blood throughout the body
• sperm duct- openings in which sperm can pass through
• oviduct- a tube connecting the ovaries and the uterus
• typhlosole- provide surface area and increase absorption of nutrients
• seminal vesicles- storms sperm made by this worm to give away
  
  
  
  

  

  
  
  Incision Guide-

Cut a slit in the dorsal surface near the posterior pin

 Dissection video

Starfish Dissection

Starfish Dissection

Starfish live in ocean on the sea bottom. Starfish breathe through their feet. Their feet are made of thin tissue that gases can easily move through. Starfish’s tubed feet and tiny bumps all over their bodies transport the oxygen from the seawater to their tissues. Starfish mainly eat clams, oysters’ sand dollars and mussels.

Fun FACT

A starfish can regenerate lost arms. This is useful if the sea star is threatened by a predator. Starfish house most of their vital organs in their arms, so some can even regenerate an entirely new sea star from just one arm and a portion of the star’s central disc. It takes almost a year for this to happen

function of external structures 

 ring of oral spines- spines around the mouth

Central dics- holds all the arms of the starfish 

arms- help with movement and capture prey

Ambulacral groove-contains the tube feet on the oral side and used to pry open the shells of bivalves

  tube feet-  used for feeding, movement, and a little for respiration

eyespot- Senses Light And Dark

madreporite- where water enters in the water vascular system

Spines-  helps protects the starfish

mouth-stomach that is pushed out to eat food

 

function of internal structures

pyloric ceeca-secretes enzymes for digestion and absorption of nutrients

gonads-  make sperm or eggs

ampulla -Fill up with water and then release to tube feet

ossicles - Plates That Fuse To Form Skeleton

stone canal- a short canal that connects the madreporite to the ring canal around the mouth

ring canal- Circular canal in the center disk

lateral canal-  Branches off of radial canal all the way down the arm and leads into the ampulla

Incision Guide

Dissection video

Grasshopper Dissection

Facts

• Grasshoppers live on all continents besides Antarctica. Most live in dry environments with lots of grass.
• They eat leaves, flowers, stems, and seeds. Occasionally they scavenge dead insects.
• They exchange oxygen and carbon dioxide between their tissues and the atmosphere through air-filled tubes called tracheae. Tracheae open to the environment through small holes called spiracles.
• In Africa and Asia, grasshoppers are known to be crop pests.

External Anatomy:

• head, thorax, abdomen: top, middle, bottom regions of grasshopper
• tympanic membrane: transmit sound from the air to the organism
• spiracle: hole used by grasshoppers for respiration; air is taken in through them and filtered by hairs in tracheae.
• ovipositor: tube that delivers eggs
• antenna: odours, touch, humidity, vibration, wind velocity and direction.
• compound eyes: can see shape, colour, movement, and tell the distance.
• mouthpieces: cut and grind food
• trochanter: attachment point for muscles
• femur: supports weight of body
• tarsus: forms ankle joint
• tibia: connects femur to tarsal segments

Internal Anatomy:

• heart (not pictured): pumps the fluid to the head from where it filters past the tissues and organs on its way back to the abdomen.
• crop: stores food
• gastric caecae: pockets of the stomach that secrete enzymes that break down food
• intestine: transports waste through the digestive system
• rectum: passageway for digested waste from the intestine to the anus

Incision Guide:

• for internal organs

• for appendages
  

Dissection Video:

Clam Dissection

Facts

• Clams live in both freshwater and marine environments.
• They eat plankton.
• They take in oxygen through the surrounding water to breathe.
• “Clams do not have any sense. They cannot smell, hear or even see because they have no noses, ears and eyes.”

External Anatomy:

• umbo: highest, most prominent part of the shell
• growth rings: age markers
• hinge ligament: located near umbo, hinges valves together

Internal Anatomy:

• gonad: reproductive organ, produces egg or sperm
• gills:respiratory structures responsible for obtaining water and food
• digestive gland: used for digestion after passing mouth
• foot: used to burrow into mud and sand
• mantle: tissue that lines valve and covers soft body of clam
• posterior/anterior adductors:on the sides of the clams, used to close shell.
• exhalant siphon:expels water and waste out of the clam
• inhalant siphon:brings in oxygen, food, and water into the clam
• teeth: ridges near anterior end of hinge that interlock when shell is closed

Incision Guide:

• cut along ventral side
  

Dissection video:

Frog Dissection

Frogs are amphibians. This means that they are born in water, but are able to live near and away from water once they become adults. Most frogs are found in areas with warm temperatures. Frogs eat small invertebrates, but some frogs species can be omnivorous. Small frogs eat insects. In the water, frogs breathe through their skin which is a thin membranous tissue that allows gas exchange to occur. Frogs can also breathe through their nostrils using their lungs. Since frogs don't have diaphragms, they must use the bottom of their mouths to push air in and out of the lungs. At rest, frogs use a respiratory surface in their mouth to breathe. Large declines in frog populations have occurred in the past 50 years due to habitat destruction, chemical pollution, climate changes, and many other human activities.

Fun Facts

Frogs’ long legs allow them to leap more than 20 times their body length.

Vocal cords first developed in frogs. Males have vocal cords that fill up with air.

Incision Guide

                               

External Anatomy 

External Nares allow air to enter.
Nictitating Membrane protects the eye.
The tympanum is the eardrum.

Vomerine and Maxillary teeth used to hold prey.
Internal nostrils used for respiration.
Eustachian Tubes provide pressure in the inner ear.
Tongue used to capture prey.
Gullet Opening is the beginning of the digestive tract.

Internal Anatomy

When we opened our frog, we didn't find eggs scattered throughout the internal cavity. However, our frog is a female because we were able to locate the oviducts which produce eggs in female frogs. In male frogs, this structure may be present but it has no vital function (vestigial structure). 

 Function of structures:
Fat Bodies- Like humans, adipose tissue insulates internal organs and protects them.
Heart- Pumps blood to the entire body.
Lungs- Used for respiration and gas exchange.
Peritoneum- Covers internal organs and holds them in place.
Oviducts- Produce eggs in females. Vestigial structure in males.
Liver- Secretes bile and helps digest food.
Stomach- Storage for food. Food digested.
Small Intestine- Most digestion and absorption of nutrients occurs here. Enzyme from the pancreas enter the duodenum.
Large Intestine- Absorbs most fluids. Prepares food for secretion.

 

 



PGlo Transformation

Purpose

The purpose of this experiment was to test the idea that cells can take in genetic information. By using the glo gene, and putting these cells in different situations we were able to see what it takes for a cell to incorporate foreign DNA into their own DNA. This also helped us learn how viruses are able to take over an organism.  

Introduction 

In this experiment we did genetic transformation. Genes contain pieces of DNA that provides the information to make the proteins. Proteins gives an organism their trait. When changed caused by genes it is consider genetic transformation and many use in science. One application would be biotechnology in the fields of agriculture and medicine. For example, with bacteria by moving genes with the help of the plasmid, which the circular DNA. Plasmid DNA usually contains more than one trait that helps the survival of bacteria. Bacteria can transfer plasmids to adapt to new environment. Bacteria becomes resistance to antibiotics because of this transfer. Green fluorescent protein or GFP can by transformed by plasmids. It causes them to glow. When the transformation is done the bacteria will glow fluorescent in the dark. The PGLO plasmid codes for this gene that is resistant to antibiotic ampicillin. To control the rate of proteins that transferred into a cell caused by gene regulation system. Sugar arabinose can be active by GFP. This procedure takes place on antibiotic growth plate

Methods

First, we put in transformation liquid into
each tube; one labeled +pGlo and another
-pGlo.

Then we put them on ice .

Next, we transfered e coli to the tubes. 

We added plasmid DNA only to the
+pGlo tube.

Then we cold shocked the tubes for
10 minutes.

While we waited we labeled our petri dishes

Next we heat shocked the cells by putting
the tubes in a water bath, and back again into
the ice.

Then we added LB nutrient broth to the
mixtures, and mixed.

Lastly, we spreaded the solutions onto
the petri dishes, and let them
incubate for one day. 

Data and Graphs:

Discussion:

The LB/-PGLO plate had the most bacteria that resembled the original untransformed E. coli colonies we initially observed. This makes sense, if we take into consideration the fact that the bacteria were removed from the starter plate, did not have any plasmid added to them, and only had LB (this is broth, or in simpler terms, food) on the plate. Regulating these features makes it a control plate. The other control plate is the LB/amp/-PGLO plate, which had zero growth, because no plasmid was added. Plasmid actually has to be added in order for bacteria to multiply in the presence of ampicillin. The transformation plates include LB/amp/+PGLO and LB/amp/ara/+PGLO. First, both plates had the plasmid for the fluorescent gene added to the E. Coli spread on them. Because of the heat shock we gave the E. Coli, holes could be made in the cell membrane of the prokaryote cells. This means that the PGLO plasmid which expresses the ampicillin resistance gene is incorporated into the E. Coli. Thus the bacteria can survive on the plates that contain ampicillin. On the other hand, cells that were not treated with DNA did not express ampicillin resistance and did not grow on the LB/amp/-PGLO plate. The LB/amp/ara/+PGLO plate had about the same amount of growth as the other transformation plate, but the genes of the plasmid will only be expressed in the presence of arabinose, so it’s on this plate that the bacteria glowed under a UV light. The transformation efficiency (efficiency by which cells take in extracellular DNA and express its genes) for this plate is 406.25 transformants/microgram. This basically reflects how competent prokaryotic cells are at including new DNA. Our results are what they were supposed to be, and they support our belief that only the cells with DNA added to them would be genetically transformed. One way to improve this lab could be to let it go on for more than one day. That way we would try to calculate rate of reproduction in order to grasp how quickly plasmids can be generated in new cells.

Conclusion :

 We found that we were able to transform the DNA of this organism using plasmids. We concluded that E. Coli did not grow. Some bacteria was able to live in the surroundings with ampicillin  and glow under UV light in a environment with arabinose. Based on these  result our  hypothesis came true. 

Gel Electophoresis Lab

Background Information:

Gel Electrophoresis is a type of DNA technology that's used to separate nucleic acids or proteins that differ in size, charge, or other properties. The separation of the molecules depends on the rate of their movement in a polymeric gel in an electrical field. The distance traveled by a DNA molecule is inverse to its size. In other words, if the DNA molecule is larger in size, then it will travel a shorter distance because it has more resistance due to its size. On the contrary, smaller DNA molecule have less resistance so they travel faster down the gel. The DNA is always placed on the cathode side (negative) because DNA is also negative so when the power source is added the  the DNA will repel away from the cathode and towards the anode(positive) side. Restriction fragments can be used to cut up the DNA molecule into bands.
Purpose:
The purpose of this lab was to use restriction enzymes to sequence DNA. Using single, double, and triple digests, we tried to figure out the number of cut sights present in the DNA sequence for each enzyme as well as the position of those cuts relative to one another.

First our teacher cast an agarose gel with wells included.

Using a pipet we loaded the contents of a reaction tube (DNA with restriction enzymes) into a well in the gel.

We repeated this procedure with each reaction liquid into a different well.

When we finished loading it looked like this.

We put our gel in the electrophoresis chamber, and allowed the DNA to electrophorese until the bromphenol blue band was about 2cm from the end of the gel.

We removed the gel.

And we examined it on a light box. We assigned sizes to the lambda DNA size marker bands, then approximate sizes to the unknown DNA fragments, and determined the total size of digested DNA.

Data and Graphs

This shows the marker's lengths, so that we can
estimate the lengths of the DNA strands for the rest of the lanes.

Discussion: 

 Gel electrophoresis was used to determine the size of the unknown DNA sequence. The size of sequence was determined to be  about 5500 base pairs in length by comparing against a known lambda DNA sequence. When the unknown DNA sample was cut with restriction enzyme PstI, there were two bands at approximately 750 and 4700 base pairs.  The PstI had cut the unknown sequence twice. PstI and SspI there were three bands at approximately  750, 2140, and 2700 base pairs. This shows that the SspI sequence had only cut once. PstI and HpaI there are two bands at approximately 750 and 4700 base pairs.  Since there were only two bands, this shows that adding the HpaI did not cut the sequence. PstI, SspI and HpaI there are three bands at approximately 750, 2858 and 1093  base pairs. This is expected after since PstI cut twice, SspI cut once, and Hpal did not cut at all; giving a total of three cuts and three bands on the gel. Further investigations could look into the discrepancy between the bands in the lane containing PstI and SspI and the lane containing PstI, SspI, and Hpal.

Conclusion: Our results demonstrate how different restriction enzymes cut the plasmid into different sizes. All the different wells should have DNA fragments of the same size because we used the same DNA, but our variables were the restriction enzymes that digested the DNA at different locations. PstI only cut the plasmid into 2. PstI and SspI combined created a plasmid with 3 different sections. PstI and HpaI also created 3 different sections even if they one of them wasn't clearly visible on the gel. The last well with all the enzymes shows a combination of the fragments.