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SNC 2D
Biology: Cells, Tissues & Organ Systems
Topic Learning Goals Homework Microscope
-‐ Identify all parts of the microscope & their function -‐ use the microscope to effectively visualize cells & tissues -‐ draw proper biological diagrams
Pg 542-‐543 pg. 25 Q5-‐8, 11
Plant & Animal Cells -‐ to identify cell parts & state the function of each -‐ recognize major differences between plant & animal cells -‐ setup a proper wet mount slide
Lab: Plant & Animal Cells pg.16 Q1-‐5 pg. 25 Q1-‐4, 14
Quiz 1. 1 -‐ Cell Parts & Function
-‐ demonstrate an understanding of cell parts & function -‐ explain the difference between plant & animal cells
Cell Cycle & Mitosis
-‐ state the importance of cell division -‐ explain the difference between interphase & mitosis -‐ identify each stage of interphase & mitosis
Lab: Mitosis pg.32 Q1-‐5 pg.37 Q2,6,7,16
Cancer -‐ describe the relationship between cell mutations & cancer -‐ contrast characteristics of healthy & cancerous cells
Blog: Cancer Cells pg.37 Q3, 10,11,14
Cell Differentiation -‐ understand how 2 gametes can grow and develop into specialized cells in the human body
-‐ understand the human uses of stem cells -‐ identify different cells in the human body
Pg.41 Q1-‐5
Quiz 1.2 – Mitosis -‐ demonstrate an understanding of interphase, mitosis & cytokinesis Plant & Animal Tissues
-‐ identify location & function of each of the 4 major tissue types in plants & animals
Pg.45 Q1-‐5 Pg.47 Q1-‐8,10-‐15
Specialized Plant & Animal Tissues
-‐ explain the importance of cell specialization -‐ describe the major specialized cells of animal & plant systems
Lab: Plant & Animal Tissues
Quiz 1.3 – Tissues -‐ explain the similarities between plant & animal tissues
Animal Organs -‐ identify major organs in the human body
Pg63 Q1-‐5,8-‐13
Plant Organs -‐ identify major organs of the plant body -‐ develop proper dissection techniques
Lab: Plant Dissection Pg.63 Q6,7,14-‐18
Organ Systems in Animals -‐Digestion -‐Circulation -‐Respiration
-‐ explain function of each of the 8 major organ systems in animals -‐ describe the importance of the circulatory, respiratory & digestive
system -‐ outline the pathway of molecular flow through the circulatory,
respiratory & digestive system
WS: Organ Systems of the Human Body Pg.71 Q1-‐5 Pg.77 Q1-‐7, 9-‐12
Organ Systems Working Together
-‐ understand that organ systems are interdependent -‐ explain how homeostasis is maintained using organ systems
pg.81 Q1-‐5 pg.86 Q1,2,5-‐7, 9-‐13
Organ Systems in Plants
-‐ explain the function of the 2 major organ systems in plants -‐ describe the importance of each of the systems
Pg.60 Q1-‐5
Quiz 1.4 – Organ Systems
-‐ demonstrate an understanding of plant & animal organ systems
Disease Prevention
-‐ explain how disease is prevent on a personal, local & international level
-‐ state the importance of disease prevention starting with self
Case Study: Ebola Blog: Disease Prevention Pg.104 Q1-‐5 Pg.111 Q1-‐4, 14
Medical Technologies -‐ explain the function & use of each of the most common medical technologies
WS: Medical Technologies Pg.101 Q1-‐16
Biotechnology
-‐ outline major uses of biotechnology in medicine & agriculture -‐ explain the process of gene therapy & genetic engineering
Complete Analysis Questions
Bioethics -‐ understand major ethical issues related to biology Blog: Ethics Frog Dissection -‐ properly dissect a multicellular organism
-‐ identify major organs of all body systems discussed -‐ complete biological diagrams for multicellular organisms
SNC 2D The Microscope
Complete the table below using the textbook.
Structure Function
stage clips
allows objective lenses to be changed
ocular (eyepiece)
controls or regulates the amount of light that enters the object being viewed
used only at low power, to help focus object
used with medium and high power for focusing
MAGNIFICATION AND ESTIMATING SIZE USING A MICROSCOPE
Magnification -‐ ____________________________ _________________________________________
Total Magnification = _______________________
Field of View -‐
Eyepiece lens Objective lens
Total Magnification
10X 4X
10X 10X
10X 40X
SNC 2D Lab: The Microscope
The microscope enables you to see details that are otherwise too small to be seen with the naked eye.
Care of the Microscope
1. Always carry the microscope with both hands (one hand under its base and the other hand on its arm).
2. Keep the microscope away from the edge of the desk. Make sure that the cord is tucked out of the way.
3. Never touch or clean the lenses with anything but lens paper.
4. When finished with the microscope, always return it to low power and lower the stage all the way. NEVER LEAVE A SLIDE ON THE STAGE.
5. Wrap the cord around the microscope and return it to its proper location.
How to Focus the Microscope
Procedure:
Part A: Preparing a Wet Mount (Banana Cells)
1. Place one drop of iodine solution in the centre of a clean microscope slide.
2. Use a toothpick to extract a very small amount of pulp from the inside of the banana.
3. Roll the pulp in the iodine on the slide. Cover the cells with a coverslip.
Part B: Focusing the Microscope
1. Place the prepared slide on the stage.
2. Swing the low power objective lens into place. While watching from the side, lower the objective lens as far as it will go (or raise the stage to the lens). Do not let it touch the slide.
3. Adjust the course adjustment knob to bring the image into view. Use the fine adjustment knob to sharpen the image.
4. While watching from the side, swing the medium power objective lens into place. Focus using only the fine adjustment knob.
5. While watching from the side, swing the high power objective lens into place. Focus using only the fine adjustment knob.
6. Once focused, draw a large single cell of the banana. Label the CELL WALL, CELL MEMBRANE, NUCLEUS, NUCLEAR MEMBRANE, CYTOPLASM, VACUOLES, and LEUCOPLASTS (These will appear as dark purple or blue bodies in the cytoplasm -‐ they are storage bodies for starch).
SNC 2D Biological Drawings
The rules for making biological diagrams may vary slightly from one instructor to another. It is always important to check what is expected.
1. All diagrams, labels, and titles should be completed in pencil only.
2. All diagrams should be on blank paper.
3. Diagrams should be drawn slightly to the left side of the page.
4. Use a ruler for all lines used to indicate a part on the diagram.
5. All labels must be printed in lower case letters.
6. Start the line indicating a part at the part you wish to name (do not use
arrowheads).
7. Lines should be drawn to the right side of the diagram whenever possible.
8. Lines should be parallel to each other whenever possible.
9. Lines should end the same distance from the right hand side of the page.
10. Stipple areas that you wish to show darker (do not shade).
11. Use clear unbroken lines to indicate the outline of parts, which have clear
unbroken boundaries.
12. Give your diagram a title.
13. Clearly print your name in the upper right corner.
14. Make your diagram as large as the space allows. Remember that you need
space to label the diagrams also.
15. Record the magnification just below your diagram and to the right.
Lab:
Name:
☐ Drawing is done on blank paper ☐ Drawing is done with sharp pencil
☐ Firm Lines only. No sketching.
☐ Only stippling
☐ Only relevant & easily seen details are included
☐ Labels neatly printed
☐ Labels have correct spelling ☐ No caps are used ☐ Labels are to the right
☐ Labels are in an even column
☐Label lines do not cross ☐ Name & Date at top
☐ Magnification at bottom right ☐ Title Underlined
☐ Drawing is large (1/2 the pg) Overall Quality of Drawing 0 1 2 3 4 5
Discussion Questions /
Total è
Comment
___________________________________ ___________________________________ ___________________________________
SNC 2D Cell Parts & Function
All living things are made of cells. Our bodies are made of between ________________ and __________________ cells. Each cell contains smaller parts called _________________. These cellular structures have special functions that maintain all of the life processes of the cell, including: __________________________________________________________
_____________________________________________________________________.
Typical Animal Cell
Typical Plant Cell
SNC 2D Cell Structure Function
SNC 2D Comparison of Plant & Animal Cells
Observing Plant and Animal Cells Learning Goal: Estimate the size of plant and animal cells. Observe the differences between animal and plant cells. Procedure:
Part A
1. Peel a translucent piece of tissue from the onion. (The smaller the piece the better.) Translucent means that you can see light through the specimen, but it is not transparent.
2. Place the piece of onion on a glass slide and add a drop or two of the iodine solution. Cover the slide with a cover slip using your best wet-‐mount making techniques.
3. Observe the onion cell under both low and high power. Make a drawing of one onion cell, labeling all of its parts as you observe them. (At minimum you should observe the nucleus, cell wall, and cytoplasm.)
Part B
1. To view cheek cells, gently scrape the inside lining of your cheek with a toothpick. DO NOT GOUGE THE INSIDE OF YOUR CHEEK! (We will observe blood cells in a future lab!!)
2. Gently tap the toothpick onto the center of a glass slide. Some of the cheek cells should fall onto the slide. 3. Add a drop of methylene blue stain (specific for animals) and cover with a cover slip. 4. Observe the cheek cells under both low and high power of your microscope. Draw a diagram of one cheek
cell and label its parts. (At minimum you should observe the cell membrane, nucleus, and cytoplasm.)
Observations: Complete proper biological drawings of each cell type listed below. These neat drawings MUST be completed using a pencil. Be sure to include magnification (use proper calculation). Cheek Cell – Low power Cheek Cell – High power Onion Cell – Low Power Onion Cell – High Power
Plants Animals
SNC 2D
The Importance of Cell Division ______________________________________________________________________________________________________________________________________________________________________________________________________ Functions of Cell Division:
1. __________________________________ - cells are constantly being injured or dying - if the remaining cells did not reproduce, your body would gradually shrink in size
and eventually die
2. __________________________________ - this is an increase in the number of cells in an organism - most cells are small and of a relatively constant size - therefore the number of cells must increase
3. _________________________________
- life must perpetuate life - unicellular organisms like bacteria must reproduce by cell division - multi-‐cellular organisms use cell division to reproduce as well
The Cell Cycle The cell cycle involves two phases:
(i) _________________________________ (ii) _________________________________
SNC 2D
Mitosis and Cytokinesis
Mitosis – __________________________________________________________________
Cytokinesis – _______________________________________________________________
Before Mitosis ___________________ The cell grows and carries out its normal functions. It then prepares for cell division by duplicating its DNA (genetic material).
Stages of Mitosis 1.
The individual chromosomes, which are made up of two identical strands of DNA, shorten and thicken. The nuclear membrane begins to fade.
2. The double-‐stranded chromosomes line up in the middle of the cell.
3. Each chromosome splits. The two strands move away from each other to opposite poles of the cell.
4. The chromosomes reach the opposite poles of the cell and a nuclear membrane begins to form around each set.
5. ______________________ Cytoplasm and its contents are split into two equal parts. Cell membrane pinches in to form two daughter cells.
Final product of mitosis: Mitosis results in two new cells that are identical to each other and to the parent cell. New cells enter .
SNC 2D Mutations & Cancer Mutations – _________________________________________________________________________ While some mutations may be beneficial to the cell, most are either neutral or damaging. Cancer – caused by a _____________________ in the genes that ______________________________. The mutation causes cell division to go out of control. In other words, cells are dividing more quickly than they should. Why are Cancer Cells Dangerous? Carcinogen – any substance or energy that causes such a mutation) Three types of known carcinogens:
(1) ___________________ (2) ___________________ (3) ___________________
Differences between Normal Cells & Cancer Cells
Normal Cells Cancer Cells • __________________ when
isolated from other cells. • divide in a _________ manner. • _________________ and
_____________ as they mature. • each has a function (or job)
• are capable of _____________ _________________________
• divide in an _________________ manner.
• have a ___________ and reduced cytoplasm
• _________________ shape or specialize as they mature.
• have _____________
3/24/2013
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Tumours
Uncontrolled cell division sometimesleads to the formation of a lump ortumour. A tumour is a mass of cellsthat continue to divide without anybenefit to the body.
March 24, 2013 2DBIOL - Cancer (Cell Division Gone Wrong) 3
Tumours
NOTE!Tumour cells are like healthy cells. They need nutrients and oxygen tosurvive and to go through the cell cycle. Thus, they need access to thebody’s blood supply. But how does the tumour get access?
March 24, 2013 2DBIOL - Cancer (Cell Division Gone Wrong) 4
Tumours
They send out chemical signals to normal cells in the surrounding area.These healthy cells respond by encouraging nearby blood vessels toexpand into the tumour mass.
March 24, 2013 2DBIOL - Cancer (Cell Division Gone Wrong) 5
3/24/2013
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Tumours
A benign tumour has no serious effect on the normal cells around it. Thenormal cells around the tumour may be crowded, but their function isunaffected. A benign cancer is not cancerous.
March 24, 2013 2DBIOL - Cancer (Cell Division Gone Wrong) 9
Tumours
BENIGN TUMOUR does not interfere with surrounding cells – it just crowds them not cancerous
March 24, 2013 2DBIOL - Cancer (Cell Division Gone Wrong) 10
Tumours
A malignant tumour, on the other hand, interferes with the work of thecells around it or destroys those cells. Malignant tumours are cancerous.Malignant tumours are also dangerous because their cells can break awayand travel to another part of the body. There, they can start a newtumour. This process is known as metastasis.
March 24, 2013 2DBIOL - Cancer (Cell Division Gone Wrong) 11
SNC 2D Cellular Differentiation Although we begin as a single fertilized cell, we contain many different cells: The process by which cells become specialized is called ___________________________. Cells that are specialized will possess _____________________________. Cell differentiation leads to a multi-‐-‐-‐ cellular organism with a greater efficiency for performing different tasks.
Stem Cells Stem cells have the potential to develop into many different cell types in the body during early life and growth.
Functions of Stem Cells in the Body
Human Uses of Stem Cells
Epithelial Cells
SNC 2D Blood Cells
Muscle Cells
Nerve Cells
SNC 2D Animal & Plant Tissues Tissues
• _______________________________________________________________________________ • _______________________________________________________________________________
The study of tissue is known as ____________________. Although very different as whole organisms, plant and animal tissues are very similar. Each has an outer _______________ tissue layer, a ______________________ tissue and a tissue for _______________________. Both plant and animal tissue can be broken into 4 categories: Animal Tissues
Plant Tissues
SNC 2D Human Body Organs
Esophagus
Lungs
Stomach
Intestines
Heart
Liver
Alveoli (Lung Tissue)
Pancreas
Trachea
SNC 2D Plant Organs
SNC 2D Animal Organ Systems
The human body is a network of systems – all linked for a common purpose – maintaining homeostasis ( a constant internal state). Cells are the smallest unit in each system. Many cells that look the same and work together form tissues. Tissues form organs (heart, kidney, liver, hands, and stomach). Organs related in function form organ systems. All of your organ systems need to be synchronized together to ensure that you have a stable internal environment.
Organ Systems
Organ System Major Organs Major Function
Digestive
Circulatory
Respiratory
Reproductive
Excretory
Locomotion
Endocrine
Nervous
SNC 2D The Human Digestive System
Pathway of Food
Digestion Occurs Where?
Mouth
Stomach
Small Intestine
Large Intestine
Rectum
Anus
SNC 2D The Human Circulatory System Flow of Blood Components of Blood
SNC 2D The Respiratory System The respiratory system is responsible for ____________________ into the body so that the organs may function properly. It is also responsible for ____________________________________. Simply put the respiratory system is responsible for the ______________________________________________________. In order to exchange gases, all living organisms have a __________________________that allows them to do this easily. Like all mammals, humans have a _________________________for exchanging gases. Anatomy of the Respiratory System
How do we exchange gases?
How we Breathe
SNC 2D WORKSHEET: ORGAN SYSTEMS OF THE HUMAN BODY Using your textbook, summarize key points for each of the systems listed below. INTEGUMENTARY SYSTEM (pg.68)
1. Main Structures making up the system: 2. What these structures do (how they work):
DIGESTIVE SYSTEM (first paragraph only) (pg. 68)
1. Main Structures making up the system: 2. What these structures do (how they work):
RESPIRATORY SYSTEM (not including breathing) (pg. 69)
1. Main Structures making up the system: 2. What these structures do (how they work):
CIRCULATORY SYSTEM (pg. 70-‐71)
1. Main Structures making up the system: 2. What these structures do (how they work) (including Capillaries): 3. Diagnostic Techniques: (pg. 82-‐83)
a) Pulse b) Blood Pressure c) Blood samples
EXCRETORY SYSTEM (pg. 71) 1. Main Structures making up the system: 2. What these structures do (how they work): 3. Diagnostic Techniques: (pg. 83)
a) Presence of White Blood Cells: b) Too little urine: c) Too much urine:
ANSWERS TO QUESTIONS #1,2,4 (PG.81)
SNC 2D Animal Organ Systems Working Together In order to maintain homeostasis, all of the organs in a system must work together – the same can be said for organ systems. Alone, each system can function but cannot form an organism. Therefore, organ systems are interdependent. Let’s think about when we are being active – which muscle systems are working together? How?
Circulatory System
Respiratory System
Skeletal System
Muscular System
Nervous System
What about when our body needs nutrients – what systems are working together?
Digestive System
Circulatory System
Muscular System
Nervous System
SNC 2D Plant Organ Systems
Most seed-‐producing plants have the same basic organs: roots, stems, and leaves. But the basic organs have many shapes, sizes, and functions in different species of plants. Various adaptations of these organs enable plants to survive in environments as different as swamps and deserts. Seed plants all have one common problem: how to get water from the ground up the stem to the leaves. Plants have adapted to a range of environments over the course of their evolution. As plants grow, their cells become specialized for particular functions. The patterns of specialized tissue vary in each plant organs-‐the root, the stem, and the leaf.
The Root System
• ______________________________
• ______________________________
• ______________________________
• ______________________________
• ______________________________
The Shoot System
• ______________________________
• ______________________________
• ______________________________
o ________________________
o ________________________
o ________________________
• ______________________________
• ______________________________
SNC 2D Disease & Prevention
Vaccinations
Antibiotic Use
Bacteria Virus
SNC 2D Medical Technology -‐ use the textbook to complete the following table.
Diagnostic Technology What is it? How does it work? What is it used to
Diagnose?
X-‐RAY
FLUOROSCOPY
RADIOTHERAPY
ULTRASOUND
COMPUTED TOMOGRAPHY
MAGNETIC RESONANCE
IMAGING (MRI)
NUCLEAR TECHNOLOGY
POSITRON EMISSION
TOMOGRAPHY
BIOPHOTONICS
SNC 2D
Biotechnology
SNC 2D Bioethics
Designer Babies
What is it? Pros Cons
Transgenic Animals
What is it? Pros Cons
GM Foods
What is it? Pros Cons
Steroid Meats
What is it? Pros Cons
SNC 2D Dissection of the Frog
Introduction Dissection is the scientific technique that allows you to separate one tissue from another. Dissection of an organism is not simply a matter of cutting and slicing. The dissection is to separate the structures of one body system from the structures of the other systems. In this way, you can see for yourself the marvellous way that an organism is put together. Of course, you will not see this unless you dissect with care and follow all instructions. You are reminded that all life is valuable. Respect your animal and do not waste this opportunity. Take your time, read carefully, observe closely and learn lots!
Evaluation is based on: 1. A full original, hand-‐drawn diagram (drawn to scale) of the digestive system and related structures of the frog. Each person must hand
in their own diagram. Include and label all of the following: (20) The Digestive System: Related Structures: a) tongue (diagram of mouth) a) liver b) vomerine teeth (diagram of mouth) b) gall bladder c) gullet (opening to the esophagus, in mouth) c) pancreas d) esophagus d) mesentery (circulatory system) e) stomach e) fat bodies e) pyloric sphincter f) spleen (circulatory system) g) small intestine g) lungs (respiratory system) h) large intestine h) heart (circulatory system) i) cloaca (anus) i) kidneys (excretory system) j) urinary bladder (excretory system) 2. An oral quiz based on the identification of various structures, and stating their function (10 marks) 3. How well you perform the dissection: • Upon completion of the dissection, your teacher will examine your specimen and determine how carefully the dissection was performed, and how well the instructions were followed.
• Students are expected to be respectful to the animals and behave maturely. • Students are expected to be respectful and considerate of other students’ feelings. Marking scheme for dissections (15 marks): 1. Cuts are made neatly as instructed. 2. Skin is pinned back. 3. Small intestine is intact and uncut. 4. Cuts are made to the sides of the mouth. 5. Eyes and ears have not been damaged. 6. Throat area has been dissected neatly.
7. The gall bladder and liver are intact. 8. The pancreas is intact. 9. The brain cavity is undisturbed. 10. The reproductive organs are undisturbed. 11. Students have behaved in a mature and responsible fashion.
(5 marks) Additional Dissection Once you have completed the required parts of this dissection, and your specimen has been marked, you may ask for your teacher’s permission to explore additional parts of the body, such as the muscular system, the skeletal system, the reproductive system and the nervous system (including the brain). Step I: External features. Pick up the frog. Feel the skin. 1. Describe the texture (feel) of the skin. ____________________________________ 2. Is there any sign of bristles, hair, feathers or scales? __________ 3. What unusual function does the frog’s skin play? Step II: Find the circular “patch” behind each eye. 1. What is the name of this patch? ___________________________________ 2. What is the function of this patch? ___________________________________________ Step III: Using the scissors, cut the mouth at each corner. Open the mouth and examine it. Rub your finger over the upper and lower jaw and the roof of the mouth. 1. Are teeth present in the upper jaw? _________ 2. Are teeth present in the lower jaw? ________ 3. Find the teeth in the roof of the mouth. What are they called? 4. What is the function of these teeth? 5. Where is the tongue attached to the mouth? 6. Label the diagram of the frog’s mouth:
SNC 2D
Step IV: Dissection (a coloured, labelled picture may be helpful when identifying the organs)
1. Place your frog on its back in the dissection tray. 2. Use four pins to pin the frog’s hands and feet to the tray. 3. Study the diagram to the right showing the required cuts to open the
abdomen. 4. Start by pinching a small fold of skin on the abdomen, just in front of the
back legs. Make a small snip into the pinched fold of skin. 5. Insert the end of the scissors gently into the first cut. Hold the scissors
horizontally so you do not cut down into the delicate structures below. 6. Keeping the scissors horizontal, follow the diagram and cut the skin up to
the rib cage, and then out to both sides. 7. Peel back the layer of skin. 8. Once the skin is peeled back, follow steps 4 to 7 to cut through the muscle
layer. Peel back the muscle to expose the tissues below. Pin the muscle flaps to the dissecting tray.
9. Take a few minutes and just look around at the major organs. Identify as many as you can. 10. Stopping as necessary to sketch your diagram of the digestive system of the frog, follow these step-‐
by-‐step instructions to identify the various organs. A careful dissection will take two full periods. a) The liver is the largest organ. It is just below the ribs and it’s a bluish-‐brown colour. The frog’s liver has three lobes. Very gently
lift the liver up so you can see the other structures. b) The gall bladder is a tiny sac-‐like structure, tucked in the middle, underneath the lobes of the liver. It may be difficult to draw the
gall bladder on your diagram. c) The stomach is a long thick tube running down the right-‐hand side of the abdomen (when you are looking down from above). The
pyloric sphincter is a thickened muscular band at the bottom of the stomach, where it attaches to the small intestine. d) The small intestine is the small coiled tube that comes off of the end of the stomach. In the first loop of the small intestine (just
beside the stomach), there is a creamy/transparent white mass. This is the pancreas. Handle it gently.
e) There are very thin transparent membranes attached to the stomach and small intestine. This is the mesentery. It helps to hold the internal organs in place, as well as holding the blood vessels (blue).
f) The spleen is a small little “bean-‐like” reddish/brown organ in the middle behind the small intestine. It is attached to the mesentery.
g) The large intestine runs from the small intestine to the cloaca (anus). This is where the feces are stored before egestion.
h) Just in front of the large intestine (and attached to the mesentery) is a transparent, colourless/greyish-‐white sac. This is the urinary bladder.
i) The long feathery yellow “finger-‐like” parts toward the back of the frog are called the fat bodies. These are where frogs store extra fat.
j) Just in front of the fat bodies is a spongy grey mass. There is one on each side of the body. These are the frog’s kidneys.
k) The sex organs are found just below the fat bodies. If your frog is a female, it may have egg masses in the abdominal cavity, or it may just have fine, tightly coiled white “oviducts”. This is where the eggs are formed. If your frog is a male, there will be two small, round testes just on top of the kidneys.
l) Go back to the liver. At the top and centre of the liver there is a small blue triangular organ-‐ this is the heart. Gently clear away the tissue in front of the heart. You can see that the frog’s heart has three chambers or sections.
m) Move the liver to one side and look behind the heart. There is a spongy pink mass-‐ this is a lung. There is a lung on each side of the liver.
n) The esophagus runs from mouth to the top of the stomach. It may be difficult to see the esophagus. If you place a probe in the gullet in the frog’s mouth and wiggle it, it may help you to see where the esophagus goes into the stomach.
o) Use the tip of the scissors to cut open the stomach. Examine the stomach contents to see what the frog has been eating. You may look at the stomach contents under the dissection microscope.
Final Evaluation
When you are finished, go back over your diagram and be sure that you have included all of the listed organs and associated tissues. Include a title for your diagram. Your diagram will be marked out of 20. Then, when you are satisfied that you can identify each structure and you know its function, ask your teacher to come over. She will test you by asking you to point to or identify 10 different structures, and state their function. She will also check your frog to see how carefully it was dissected and assign a mark out of 10 for the dissection. Each partner will be tested individually.
