Laboratory Natural Science 1º ESO

First Term

LABORATORY NATURAL SCIENCE  1 º ESO

Name and surname: ___________________________ Group: __ Table-pupil: __ Date:______

ALGAE

They are members of the Protoctista Kingdom. They can be unicellular and multicellular organisms. Algae’s cells are equal and they do not form tissues.

Multicellular algae can be brown, red or green colour due to the type of pigments that predominate in their cells. All algae have got chloroplasts, which can be easily observed under the microscope.

OBJECTIVES: Learn to use the optical microscope.

            Observation of plant cells which contain chloroplasts.

 

MATERIALS

·         Algae of different species.

·         Microscopes.

·         Slides and cover slip.

·         Scalpel.

·         Lancets and dissecting needles.

·         Tweezers

·         Staining tray.

PROCEDURE

1.    Place the alga on a microscope slide and make very small cuts with the scalpel in order to obtain a sample. Add a drop of salt water on the algae’s fragments and remove the excess of algae. Put the covers slip on the dampened seaweed and observe it under the microscope.

2.    Observe the sample with the lower lens to find the algae cells and try to distinguish the nucleus and the chloroplasts. Change to a higher lens to observe the inner part of the cells.

QUESTIONS

1. Draw what you have seen with an overall magnification of 400 x .

   Overall magnification: Magnification of the eyepiece x Magnification of the objective lens

2. What kind of nutrition have algae got?

    What do you call the organelles that perform this type of nutrition?

3. Can you see the cell wall?

4. What are the colours observed inside the cell?

LABORATORY NATURAL SCIENCE 1 º ESO

Name and surname: ___________________________ Group: __ Table-pupil: __ Date:______

Observation of plant cells

Plant cells are eukaryotic cells which have a wall cell and a large vacuole. Some of these cells 
have chloroplasts to carry out photosynthesis.

These types of cells can be observed in the epidermic tissue inside a bulbe of the onion.

OBJECTIVE:  Observation of plant cells which do not contain chloroplasts.

MATERIALS

·         An onion.

·         Microscopes.

·         Slides and cover slip.             

·         Scalpel or lancets.

·         Tweezers

·         Staining tray.

·         Lugol.

PROCEDURE

1.    Cut a little fragment of the inner epidermic tissue in the 3^th or 4^th layer of the onion. Detach it with the tweezers.

2.    Put the epidermic tissue over the slide. Carry the slide over the staining tray.

3.    Add a drop of Lugol and wait during 2 minutes for staining.

4.    After 2 minutes, put the cover slip on the dampened tissue and observe it under the microscope.

5.   Observe the sample with the lower lens to find the plant cells and try to distinguish the nucleus, the vacuole and the cell wall. Change to a higher lens to observe the inner part of the cells.

QUESTIONS:

1. Draw the cells you have seen with an overall magnification of 100X or 400 X. Write down the names of their organelles.

Magnification =

   Overall magnification: Magnification of the eyepiece x Magnification of the objective lens

2. What kind of nutrition have plants got?

  3. What do you call the organelles that perform this type of nutrition?

4. Name two cellular structures found in plant cells but NOT in animal cells.

5. Name three cellular structures found in plant cells AND in animal cells.

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Second Term

LABORATORY CN 1º ESO

Name and surname: _________________________ Grupo: ­­­__ Table-Pupil: __ Data: ________

 ARTHROPODS

 OBXECTIVES:

A) Observe some arthropods and their structures.

B) Learn the use of the microscope.

MATERIALS

•Collection of microscopic samples.

• Microscopes.

PROCEDURE

1. Put the slide containing the sample on the microscope.

2. Observe it with the minimum magnification. If you can see well the animal, try to identify its structures.  Change to a greater magnification to draw the parts of the animal.

  

QUESTIONS

1. Draw the structures you have observed at 40 or 100 magnification.

   

Magnification: Eyepiece x lens

 2. What structures have you observed?

 3. What is its function?

 4. Which animal they correspond to?

 5. Is it a vertebrate or an invertebrate animal?

  

6. Classify it according to the type of arthropods:  Arachnid, Crustacean, Insect or Myriapod.

7. Does it have any kind of skeleton? Is it external or internal?

  

8. Do you know its relationship with people?

Third Term

LABORATORY CN 1A

Name and surname: ________________________ __Table/Pupil: ___ Date: __________

DENSITY

Density is a specific property of matter that relates the mass of a substance to the volume it occupies.

Density is used to identify materials, as each substance has a density different from the others.

Objective: To find out the density of a solid in order to identify it.

Materials required:

• Precision digital scales.
• Test tube of 100 ml (100 cm3).
• Spheres and cylinders of metal.
• Pocket calculator.

Procedure:

1. Measure the mass (Ms) of the solid material with the scales.                 M_s =

2. Fill the test tube with water up to a volume equal to 50 ml.                   V₁ = 50 cm3

3. Submerge the solid sample in water and note the new volume.             V₂ =

4. Work out the volume of the solid material (Vs)                                    V_s = V₂ - V₁ =

5. In order to work out the density of the solid material, you must lately divide its mass by the volume it occupies:

      d = M/V

QUESTIONS:

a) How is the solid body's shape?

b) What metal is the solid body made of?

c) What is the density value you have obtained?

d) What is the density of this metal from the periodic table of the elements?

e) Work out the difference between the density values from c) and d).