Laboratory Manual for Practicals 1º Bach. Pilar Carnicero ... · Laboratory Manual for Practicals 1º Bach. Pilar Carnicero Márquez B. Test for a reducing sugar (glucose) Procedure:

Laboratory Manual for Practicals 1º Bach. Pilar Carnicero Márquez


Experiment 1: CONDUCT A QUALITATIVE TEST FOR: STARCH AND A

REDUCING SUGAR, E.G. GLUCOSE.

Safety: Fehling B solution is corrosive. Use disposable gloves.Wash off with cold water in the case of skin contact. Do not touch the iodine solution. Wash off with cold water in the case of skin contact.

Materials/Equipment: Starch solution (0.5%) Glucose solution (1%) Water Lugol Fehling A solution Fehling B solution 6 boiling tubes Pipettes/droppers Hot water bath (80°C - 100°C) Test tube racks Disposable gloves Timer Beaker for dirty pipettes/droppers

A. Test for starch

Procedure: 1. Label the boiling tubes W for water, A for Solution A and B for

Solution B. 2. Place 3 ml of the water into tube W. This acts as the control. 3. Place 3 ml of Solution A into tube A. 4. Place 3 ml of Solution B into tube B. 5. Add 1 drop of lugol to each tube. 6. Swirl each tube.

7. Record result. 8. Place the tubes into the hot water bath and heat for a few minutes. 9. Record result:

Conclusion/Comment:

Sample Initial colour After lugol After heating

W

A

B

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B. Test for a reducing sugar (glucose) Procedure:

1. Label the boiling tubes W for water, A for Solution A and B for Solution B.

2. Place 3 ml of the water into tube W. This acts as the control. 3. Place 3 ml of Solution A into tube A 4. Place 3 ml of Solution B into tube B 5. Add 1 ml of Fehling A and 1 ml of Fehling B 6. Swirl each tube 7. Carefully place the tubes in the hot water and heat for 5 min. 8. Remove the tubes from the water and place in the test tube rack. 9. Record result:

Conclusion/Comment:

Sample Initial colour After Fehling After heating

W

A

B

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Experiment 2: PREPARE AND EXAMINE ONE ANIMAL CELL,

UNSTAINED AND STAINED, USING THE LIGHT MICROSCOPE.

Materials/Equipment:

Microscope 2 Microscope slides Markers 2 Cover slips Wash bottle Disposal jar for slides Filter paper/absorbent paper Disposable inoculating loop/Spoons Methylene blue stain (1%) Timer Seeker/mounted needle Disposable gloves

Procedure

Unstained

1. Familiarise yourself with all procedures before starting. 2. Record the safety procedure required to minimise the identified risks. 3. Set up the microscope. 4. Swab inside cheek surface with a disposable inoculating loop (your spoon) and transfer the sample to the slide. You need to get as much sample as possible. 5. Cover the sample with one small drop of water. 6. Apply this cover slip to the preparation as follows:

a.Place the cover slip at the edge of the water at an angle of 45º to the slide.

b.Slowly lower the cover slid onto the water, supporting it with the seeker/mounted needle, until it is in place. This helps to avoid trapping air bubbles.

7. Dry the slide if necessary and label it. 8. Examine under the microscope following the usual procedure. 9. Draw labelled diagrams of what you see at x100 and at x400.

Result

Conclusion/Comment

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Stained

1. Swab inside cheek surface again using a disposable inoculating loop/swab and transfer the sample onto the second slide. Put the loop/swab into the disposal jar. 2. Air dry the slide (approx. 1 min). 3. Cover the sample with one drop of methylene blue solution. 4. Allow to stand for 1 minute. 5. Gently, using the wash bottle, wash excess stain from the slide. 6. Apply a cover slip to this preparation as specified in the previous procedure. 7. Dry the slide carefully with filter paper/absorbent paper and label it. 8. Examine under the microscope following the usual procedure. 9. Draw labelled diagrams of what you see at x100 and at x400.

Result:

Conclusion/Comment

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Experimento 3: PREPARE AND EXAMINE ONE PLANT CELL,

UNSTAINED AND STAINED, USING THE LIGHT MICROSCOPE (x100,

x400)


Microscope 2 Microscope slides Markers 2 Cover slips Disposal jar for slides Filter paper/absorbent paper Sharp knife/scissors Tweezers Dropper Lugol solution Timer Seeker/mounted needle Disposable gloves Chopping board

Procedure

Unstained 2. Familiarise yourself with all procedures before starting. 3. Record the safety procedure required to minimise the identified risks. 4. Set up the microscope. 5. Place a drop of water on the slide. 6. Cut the onion in half. 7. Separate two fleshy leaves and locate the epidermis between them. 8. Peel off the epidermis and cut it into small pieces. 9. Put these pieces into water in a petri dish.

10. Transfer one piece into the drop of water on the slide being very careful. They shouldn’t fold.

11. Apply the cover slip. 12. Dry the slide if necessary and label it. 13. Examine under the microscope following the usual procedure. 14. Draw labelled diagrams of what you see at x100 and x400. 15.Result:

Conclusion/Comment

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Stained

1. Prepare another slide as above and stain as follows. 2.Place a drop of iodine solution at one side of the cover slip and draw it across the plant tissue. by placing the edge of a piece of filter paper at the opposite side of the cover slip. 3.Dry the slide carefully with filter paper and label it. 4.Examine under the microscope following the usual procedure. 5.Draw labelled diagrams of what you see at x100 and x400.

Result:

Conclusion/Comment

What differences did you observe between animal and plant cells?

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Experimento 4: EXAMEN DE MUESTRAS DE TEJIDOS VEGETALES Y

ANIMALES AL M.O.

Materiales: Microscopio Diversas muestras de cortes de plantas Cuaderno de laboratorio

Procedimiento: Observar las muestras, identificar las partes indicadas y dibujar un diagrama de lo observado. Comparar con diagrama de internet.

Muestras:

1. Estomas: Stomates à plat de tulipe Estomas de Laurus nobilis

2. Stomates Tige Asperger ; Tallo monocotiledónea (espárrago): A observar de fuera a dentro: cutícula, epidermis con estomas, colénquima, parénquima, haces vasculares dispersos por el parénquima.

3. Tige de clématite; Tallo de dicotiledonea: A observar de fuera a dentro: Tejido epidermico (se ve algún tricoma), posiblemente colénquima anular, haces vasculares en un anillo rodeando parénquima.

4. Tubes criblés Bryone: (Tubos cribosos Bryonia dioica (dicotiledónea): A observar: Haces vasculares: xilema con conductos más gruesos (tráqueas) floema (tubos cribosos con células acompañantes) (la muestra no está muy bien)

5. Fuelle de Houx CT (hoja): A observar: Cutícula, epidermis, estomas, parénquima en empalizada, parénquima esponjoso o lagunar, haz vascular, fibras de tejido de sostén.

6. Tallo monicotiledóneas: A observar de fuera a dentro: Muestra muy rota, pero se observan bien la cutícula, el tejido epidérmico, los estomas y un anillo posiblemente de colénquima anular (anillo interno con células de paredes celulares muy gruesas)

7. Rizoma: A observar: Epidermis, haces vasculares, parénquima, anillo de tejido de sostén cercano a la epidermis.

8. Osificación: A observar: Tejido cartilaginoso: lagunas, condrocitos y matriz extracelular.

9. Cartílago hialino: A observar: Pericondrio, cartílago con laguna, condrocitos y matriz extracelular.

10. Cartílago elástico: A observar: Pericondrio (un poco roto, muy condensado), tejido cartilaginoso: lagunas, condrocitos y matriz extracelular.

11. Tejido epitelial queratinizado - Epidermis: A observar: Estrato córneo (células queratinizadas, aplanadas, muertas), estrato granuloso, estrato espinoso.

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Experimento 5: MITOSIS EN CÉLULAS DE RAÍZ DE CEBOLLA

Materiales: Microscopio Portaobjetos Cubreobjetos Aguja enmangada Pinzas Palillos Mechero Tijeras Papel de filtro Vaso de precipitados Vidrio de reloj Orceína A Orceína B

Procedimiento: 1. Llenar un vaso de precipitados con agua y colocar un bulbo de cebolla

sujeto con dos o tres palillos de modo que la parte inferior quede inmersa en agua. Al cabo de 3-4 días aparecerán numerosas raicillas en crecimiento de unos 3 o 4 cm de longitud.

2. Cortar con unas tijeras unos 2-3 mm de los extremos de las raicillas y depositarlo en un vidrio de reloj en el que se han vertido 2-3 ml de orceína A.

3. Calentar suavemente el vidrio de reloj a la llama del mechero durante unos 8 min., evitando la ebullición, hasta la emisión de vapores tenues. ¿No dejes que hierva! Debe quedar líquido al final de los 8 min.

4. Con las pinzas tomar uno de los ápices de las raicillas y colocarla sobre un portaobjetos, añadir una gota de orceína B y dejar actuar durante 1 min.

5. Colocar el cubreobjetos, con mucho cuidado sobre la raíz. Con el mango de una aguja enmangada dar unos golpecitos sobre el cubre sin romperlo, de modo que la raíz quede extendida.

6. Sobre la preparación colocar unas tiras de papel de filtro, 5 o 6,. Poner el dedo pulgar sobre el papel de filtro en la zona del cubreobjetos y hacer una suave presión, evitando que el cubre resbale. Si la preparación está bien asentada no hay peligro de rotura por mucha presión que se realice.

7. Observar al microscopio.

Observación microscópica:Se realizará a fuertes aumentos. La orceína A reblandece las membranas celulares y la B completa el proceso de tinción. Con la presión sobre el porta de la preparación se logra una extensión y difusión de las células del meristemo de la cebolla. La preparación presenta el aspecto de una dispersión de células por todo el campo que abarca el microscopio. Se observan células en diversas fases o estados de división celular. Se ven los cromosomas teñidos de morado por la orceína. El aspecto reticulado, así como el mayor tamaño de algunos núcleos corresponde a las células que se encontraban en los procesos iniciales de la división mitótica.

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Experimento 6: IDENTIFICACIÓN DE PLANTAS. EMPLEO DE CLAVES

DICOTÓMICAS.

Materiales: Guía de los árboles de la península y Baleares, Francisco Santolalla. Especies en el parque Porzuna, Mairena del Aljarafe

Procedimiento: 1. Siguiendo la clave identificar una a una todas las especies indicadas. 2. Apuntar el recorrido seguido en la guía para llegar a la especie. 3. Hacer una foto de la especie o buscarla posteriormente en internet. 4. En el cuaderno de laboratorio presentar resultados

Resultados:

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Experimento 7: DISSECT, DISPLAY AND IDENTIFY AN OX’S, A SHEEP’S

OR A PIG’S HEART.


Heart Dissecting board/white tray Scalpel Seeker Fine scissors Forceps Disposable gloves Paper towels

A. Observation:

Procedure:

1. Wash the heart with cold water. Drain and dry it with paper towels. 2. Place the heart on the dissecting board/white tray so that the front (ventral)

side is facing up. The front of the heart is recognised by feeling the sidewalls. The left side will feel much firmer than the right side. To further identify the front of the heart observe a groove that extends from the right side of the broad end of the heart diagonally downward. This groove is the location of a coronary vessel.

3. Locate the following chambers of the heart: • left atrium - upper chamber on your right • left ventricle - lower chamber on your right • right atrium - upper chamber on your left • right ventricle - lower chamber on your left

4. Note the main blood vessels located at the broad end of the heart. Locate: • the aorta • the pulmonary artery

• the vena cava (or cava vein) • the pulmonary veins

5. Draw a sketch

Result:

Conclusion/Comment

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B. Dissection:

Procedure:

6. Make a shallow cut in the left ventricle and left atrium following the lines in Fig. 3

7. Using your fingers, push open the heart at the cut to examine the internal structure. If there is blood inside the chambers, rinse out the heart.

8. Observe the different sizes of the chambers. 9. Locate the mitral valve between the left atrium and left ventricle. This valve

consists of TWO flaps. 10. Insert the forceps under the chord tendinae and notice that they extend

from the valve to the papillary muscles. 11. Repeat steps 8 to 10 for the other side of the heart. 12. Notice the difference in thickness between the walls of the left and right

ventricles. 13. Locate the tricuspid valve between the right atrium and the right ventricle.

This valve consists of three flaps. 14. Insert the seeker (or your finger) through the arteries and veins in order to

identify them. 15. Using the scalpel cut open the aorta and observe the semi-lunar valve

(“válvula aortic”). Note the three half-moon flaps of this valve. 16. Find two small openings at the base of the aorta just above the semilunar

valve. These lead into the coronary arteries. Insert the seeker into a coronary artery to trace its pathway.

17. Flag label the parts identified and draw a labelled diagram of the internal structure of the heart.

18. Wash the dissecting instruments after use.

Result and Conclusion:

Draw a sketch/label a picture:

Chamber Size - smal/large Wall - thin/thick

Left atrium

Right atrium

Left ventricle

Right ventricle

Valve type Number of flaps

Mitral

Tricuspid

Semi-lunar (válvula aórtica)

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Experimento 8: DISSECT, DISPLAY AND IDENTIFY AN OX’S, A

SHEEP’S EYE.


Lamb’s eye Scalpel Sharp scissors Dissection tray Gloves Lab notebook

Procedure:

1. Place the eye on the dissection tray. Examine the front of the eye and locate the eye-lid, cornea, sclera (white of the eye) and fatty tissue. Examine the back of the eye and find fatty tissue and the optic nerve. If the optic nerve is not visible move the fatty tissue around until the nerve is exposed.

2. Use your scissors to cut away the the eye-lid, muscle and fatty tissue from both the front and rear surfaces of the eye. Be careful not to remove the optic nerve. Cut along the surface of the sclera until all the tissue is removed and your specimen looks similar to the photographs you see here. The sclera is very tough so you do not need to worry about cutting into this layer of the eye. When

you have finished removing the tissue surrounding the eye identify the sclera, cornea and optic nerve.

3. Place your eye specimen in the dissection pan. Turn the specimen so the cornea is on the left and the optic nerve is on your right. Select a place to make an incision of the sclera midway between the cornea and optic nerve. Use the point of a very sharp razor blade to make a small cut through the sclera. Fluid should ooze out of the eyeball when you have cut deeply enough.

4. Insert the point of the scissors into the slit made by the razor blade and cut the sclera with a shallow snipping motion. Turn the eye as you continue the cutting action. Cut the sclera all the way around the ball of the eye. You will need to support the eye in the palm of your hand while you complete this step of the dissection. Do not be surprised if some fluid from the eye oozes from the slit as you make this cut.

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5. Arrange the two hemispheres of the eye as you see in the left photograph. Observe the semi-fluid vitreous humor that fills the central cavity of the eye. It is transparent in the living eye but might be cloudy in the preserved specimen. The vitreous humor along with the aqueous humor helps to maintain the shape of the eye. The retina lines the posterior cavity of the eye. Use your forceps to lift and pull the retina back from the underlying choroid layer. See the photograph on the right side below. Notice that the retina is only firmly attached to the choroid at one place. This region is the blind spot. Here the nerve fibres leave the retina and form the optic nerve which is directly behind the blind spot.

6. Use your forceps to peel the retina away from the underlying choroid coat. The retina should remain attached at the blind spot. The choroid coat is dark and relatively thin. Use your forceps to gently separate the choroid from the outer sclera. Verify that the eye has three distinct layers, the retina, choroid and sclera. The choroid contains an extensive network of blood vessels that bring nourishment and oxygen to itself and the other two layers. The dark color, caused by pigments, absorbs light so that it is not reflected around inside of the eye.

7. Use your forceps and needle to remove the vitreous humor from the anterior hemisphere of the eye. This will take some time and effort as the semi-fluid material separates easily. It helps to turn the hemisphere on edge and to use a scrapping motion to remove the fluid. Try not to disturb the lens that is just below the vitreous humor.

8. Removal of the vitreous humor reveals the lens, ciliary body and suspensory ligaments. In the normal condition the lens is transparent

9. Remove the lens by pulling it free from its attachments.

10. When the lens is removed, an opening, allowing light to enter the eye is seen. This opening, the pupil, is located in the center of the iris. Two muscle layers of the iris regulate the size of the pupil. One layer increases the pupil size with decreasing light intensity and the other layer reduces pupil size with increasing light intensity. In humans the pupil is circular. A second cavity or space is present between the iris and the cornea. This space is filled with a second semi-liquid fluid, the aqueous humor. This fluid, like the vitreous humor helps to maintain the shape of the eye. Glaucoma is a condition where the fluid pressure becomes too high causing eye damage.

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Result and Conclusion:

Draw sketchs/label pictures:

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Experimento 9: SHEEP’S BRAIN DISSECTION.


Lamb’s brain Scalpel Sharp scissors Dissection tray Gloves Lab notebook

Procedure: COMPLETAR

https://www.biologycorner.com/anatomy/sheepbrain/sheep_dissection.html

http://www.hometrainingtools.com/a/brain-dissection-project

http://psych.hanover.edu/classes/neuropsychology/Syllabus/Labs/DISSECTION.pdf

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https://www.biologycorner.com/anatomy/sheepbrain/sheep_dissection.html

http://www.hometrainingtools.com/a/brain-dissection-project

Documents

Laboratory Manual for Practicals 1º Bach. Pilar Carnicero ... · Laboratory Manual for Practicals 1º Bach. Pilar Carnicero Márquez B. Test for a reducing sugar (glucose) Procedure: