Biology experiments

Mandatory experiment: to examine plant

cells under a light microscope.

Place some onion tissue on a slide.

Cover with iodine stain.

Leave for a minute.

Examine with the microscope, using

the different lenses.

Mandatory experiment; To test for

the presence of starch.

iodine

(red)

food sample

1. Place a small quantity of the

food which you want to test into

a test tube.

2. Add 2 drops of iodine indicator.

3. If starch is present in the food

sample it will turn blue/ black.

4. Repeat for different food

samples

Mandatory experiment; To test for

the presence of glucose.

boiling water

food and

benedict's solution

1. Place a small quantity of the

food which you want to test into

a test tube.

2. Cover with Benedict’s solution

(blue).

3. Place the test tube into boiling

water.

4. If glucose is present in the food

sample the solution will turn

from blue to brick red.

5. Repeat for different food

samples.

Onion

cells

Mandatory experiment; To test for

the presence of protein (the Biuret

test).

1. Add a small amount of the food to

be tested to a test tube.

2. Add an equal amount of Biuret’s

reagent.

3. Shake the test tube. If a

permanent violet colour develops

in the mixture protein is present.

Mandatory experiment; To test for

the presence of fat in a food sample.

1. Crush a sample of the food against

a piece of brown paper.

2. If a permanent translucent spot is

left on the paper then fat is

present in the food sample.

Mandatory experiment; To investigate

the conversion of chemical energy in

food to heat energy.

Procedure;

Materials needed, a crisp, test tube, water,

thermometer, measuring cylinder, retort

stand, white coat and goggles.

We held the rice cake with a tongs and set it

on fire. Then we held the burning rice under

a test tube of water and heated the water

with it. We measured the rise in

temperature of the water with the

thermometer.

Mandatory experiment; To show the

action of amylase enzyme on starch.

water at 37oC

A B

Starch only Starch and amylase

enzyme

1. In test tube A put starch only.

2. In test tube B put some starch

and a few drops of amylase

enzyme solution.

3. Place both in a beaker of warm

water. The enzyme works best in

warm conditions.

4. After 10 minutes, take out a small

amount of A and B and test them

with iodine solution.

5. ‘A’ will turn blue/ black due to the

presence of starch.

6. ‘B’ will not change the colour of

the iodine because the enzyme has

converted all of the starch to

maltose.

7. Test both test tubes with

Benedict’s solution.

8. A shows no reaction to it.

9. B changes the blue benedict’s

solution to brick red. This shows

that test tube B now contains

sugar. This must be due to the

presence of the enzyme.

Mandatory experiment; To

demonstrate that expired air has more

carbon dioxide than inhaled air.

A

B

limewater

Expired air

Blow through ‘A’.

This forces the air that you

exhale to pass through the

limewater.

Time how long it takes for the

limewater to turn milky-white.

Inspired air

Suck air through ‘B’.

This forces the inhaled air to

bubble through the limewater

before it enters your lungs.

Time how long it takes to turn the

limewater milky-white.

Results and conclusions

The exhaled air turns the limewater in

seconds while the inhaled air takes

several minutes. Therefore, we can

conclude that exhaled air contains more

carbon dioxide.

Mandatory experiment; To show that

starch is produced by a photosynthesising

plant

Leaves make glucose in photosynthesis but

store it as starch. If we can show the

presence of starch in the leaf we can

demonstrate that photosynthesis has taken

place.

Place a leaf in boiling water. This

softens the leaf cells and makes it

easier to take out the chlorophyll

from the leaf.

1

2

3

45 6

7

8

9

1 10

2

3

45 6

7

8

9

11

boiling

water

hot plate

leaf

Place the leaf into boiling alcohol.

This removes the chlorophyll from

the leaf.

1

2

3

45 6

7

8

9

1 10

2

3

45 6

7

8

9

11

boiling

water

hot plate

leaf

boiling

alcohol

Place the leaf back into boiling water.

This re-softens the leaf.

The leaf is placed on a dish and

covered with iodine. If starch is

present then the leaf will go blue

black in colour.

Experiment; To show that water, oxygen

and heat are needed for germination

Set up the apparatus as shown below.

The seeds in A will germinate

because they have warmth, oxygen

and water.

The seeds in B will not germinate

because they are lacking water.

The seeds in C will not germinate

because they are lacking oxygen

(boiled water has no oxygen)

The seeds in D will not germinate

because they are too cold.

Experiment; To show the presence of

micro-organisms in the air and soil.

Set up the apparatus as shown above.

Allow the three dishes to sit upside-

down in a warm room for two days.

Examine the plates.

Record your results.

A should remain clear.

B and C should have lots of bacterial

and fungal colonies growing on the

plates, showing that soil and air

contain micro-organisms.

Bacterial colonies appear as shiny

dots of liquid on the plates and

fungal colonies appear as fluffy or

powdery growths.

Title of experiment 9(a); To study a local

habitat

Description of the habitat; The ground

behind the school.

Map;

Weather conditions; Dry, sunny, no wind.

Soil temperature; 150C in the sun, 110C in

shade.

Wind direction; no wind

Light intensity; bright and sunny.

Petri dish +

Sterile agar

Petri dish +

sterile agar

Opened for

10 minutes

Petri dish +

Sterile agar

Sprinkled

A B C

Chemistry experiments

Experiment; To separate soil and water by

filtration

Filter funnel

filtrate

Soil and water

1. Pour the soil and water through the

filter funnel.

2. The soil will stay in the filter paper and

the water seeps through into the flask.

3. The filtered water is called the filtrate.

Experiment; To separate salt and water ( by

evaporation)

1. Boil the salt water until the water has

almost boiled off completely.

2. Boil off the remaining water by placing

the dish on a beaker of boiling water.

Experiment;To separate sand and salt

1. Dissolve the sand and salt in water in a

beaker.

2. Filter off the sand.

3. Then boil off the water in an

evaporating dish.

Experiment; To separate copper sulfate

from water

Liebig condenser

Distillate

Bunsen burner

Thermometer

copper sulphate solution

1. Place the copper sulphate solution in the

round-bottom flask.

2. Heat until the solution starts to boil.

3. As the water evaporates (changes from

a liquid to a gas) it leaves the flask

through the condenser’ as steam.

4. The condenser has a ‘jacket’ of cold

water constantly flowing around its

outer section.

5. This causes the steam to condense back

into liquid water.

6. The water collected in the flask on the

right is called the distillate.

Experiment; To separate a mixture of dyes

by chromatography.

Chromatography paper

dye mixture

to be separated

solvent

1. Place a small spot of the dye mixture to

be separated as shown on a piece of

chromatography paper.

2. Place the paper into a solvent in a closed

glass container, making sure to keep it

above the solvent level.

3. The solvent will soak up along the paper

carrying the dye with it.

4. The colours in the mixture will travel at

different speeds up the paper because

some are more soluble in the solvent

than others.

5. Eventually, all the colors will separate

from each other.

Experiment; To make a solution of copper

sulphate and grow copper sulphate crystals

1. Add a small quantity of copper sulphate

to some water in a beaker and stir well

to dissolve.

2. This is a solution of copper sulphate.

3. The water is the solvent.

4. The copper sulphate is the solute.

5. Continue to add more copper sulphate

until no more will dissolve. This is a

saturated solution of copper sulphate.

6. Heat the beaker gently and you will find

that you can get more to dissolve. This

is a super saturated solution.

7. Allow the solution to cool slowly and

observe crystals of copper sulphate will

form in the beaker.

Title; To find the pH of a variety of

substances using universal indicator paper.

Planning; The teacher gave us out the

materials and chemicals for the testing. He

showed us how to use the indicator paper and

then we tested the substances given.

Procedure; We placed small pieces of

universal indicator paper on a white tile and put

a drop of each of the solutions being tested, in

turn, on each of the test papers. We noted the

colour change which occurred each time (see

the table below).

Conclusions: Many household substances are

either acids or bases. The pH of these tells

you how strong or weak they are.

Title; To show that the percentage of

oxygen in the air is 21%.

Procedure

• The alcohol uses up all the oxygen in

burning and the flame goes out.

• Water rushes in from outside to fill the

space which the oxygen had taken up.

• The water rises from 0 to 20ml. This

means that the volume of oxygen in the

container was 20ml.

Conclusion;

• Air contains 20% oxygen.

Title; To show the presence of carbon

dioxide in the air.

Result & conclusion

The limewater will go milky white. This proves

that there is carbon dioxide in the air.

Title of experiment; To show the presence

of water vapour in the air

Substance pH

HCl 1

NaOH 13

H2SO4 1

Orange 4

Lemon 4

Window cleaner 8

Tooth paste 8

Vinegar 4

Saliva 8

Procedure

• Water vapour in the air will condense

into water on the side of the test tube.

• After a while it will drip onto the

copper sulphate turning it blue in colour.

• This colour change is proof of the

presence of water (in air).

Title; To prepare a sample of oxygen gas

Procedure

• Set up the apparatus as shown in the

diagram above.

• Release the hydrogen peroxide into the

conical flask.

• A reaction takes place which liberates

oxygen gas.

• The gas is collected over water.

• Several test tubes of the gas may be

collected at a time and tested.

Title; To prepare a sample of carbon dioxide

gas and test it

• Set up the apparatus as shown in the

diagram above.

• Release the hydrochloric acid into the

conical flask.

• A reaction takes place which liberates

carbon dioxide gas.

• The gas is collected over water.

• Several test tubes of the gas may be

collected at a time and capped.

• Bubble the gas directly through a test

tube of limewater. It should turn milky

white. This is the test for carbon

dioxide gas.

• Bubble the gas directly through a test

tube of blue litmus solution. It should

turn red. This shows that carbon

dioxide gas is an acid.

• Dip a lighting splint into a beaker of

the gas. The splint will go out. Carbon

dioxide does not support combustion.

Title; To show the presence of dissolved

solids in water

Procedure

• Weigh a beaker on an electronic balance

and record the result.

• Pour 50ml of water into the beaker and

heat it until all of it has evaporated.

• Allow it to cool and reweigh the beaker.

Record the result.

Results and calculations

• Mass of beaker (start) = 133.39g

• Mass of beaker (end) = 134.11g

• Mass of solids = 0.72g

Title; To test samples of water for

hardness

Procedure

Add a drop of soap solution to all three

samples of water.

Shake the test tubes and record which of the

samples produce the most suds.

Title; To titrate hydrochloric acid (HCl) and

sodium hydroxide (NaOH) and prepare a

sample of sodium chloride (NaCl)

Procedure

• We placed 10 ml of NaOH in the conical

flask using a pipette.

• We filled the burette with HCl.

• We put 2 drops of indicator into the

base.

• It turned YELLOW.

• We added acid into the base until it

changed from YELLOW to PINK.

• At this point all the base is neutralised.

We noted how much acid was needed.

• We carried out the procedure again

without the indicator and added the

right amount of acid.

• Then we boiled off all of the water to

leave only salt (NaCl).

Title of experiment; To demonstrate that

oxygen and water are necessary for rusting

• The nails in ‘A’ rust very badly within

two days. This is because they have

both oxygen and water.

• The nails in ‘B’ do not rust, because they

have no oxygen.

• The nails in ‘C’ do not rust, because they

have no water.

Title; To investigate the reaction between

HCl and metals and to test for hydrogen

gas.

Procedure

• Take a small piece of magnesium and

place it in a test tube of hydrochloric

acid.

• Hold your thumb against the mouth of

the test tube until you feel pressure.

• Remove your thumb quickly and place a

match at the opening of the test tube.

Results and conclusions; The hydrogen gas

which had collected in the test tube lights with

a loud pop. This is the test for the presence of

hydrogen gas.

Mandatory Physics Experiments

Mandatory experiment: To find the

density of a regular rectangular block

Find the mass of the block with an

electronic balance.

Find the volume by multiplying

l x b x h.

)volume(cm

mass(g)Density

3

Mandatory experiment: To density of an

irregular shaped object, such as a stone.

Find the mass of the stone with an

electronic balance.

Find the volume with an overflow can

or graduated cylinder.

)volume(cm

mass(g)Density

3

Mandatory experiment: To find the

density of a liquid (water)

Find the volume of the water by

reading the side of the graduated

cylinder.

To find the mass of the water make

two measurements, (i) Get the mass

of the graduated cylinder. (ii) Get

the mass of the graduated cylinder

and the water.

)volume(cm

mass(g)Density

3

Mandatory experiment: To investigate

Hooke’s law of spiral springs

Set up the apparatus as shown.

Measure the length of the spring and

pan before any weights are added.

Now add a weight to the pan.

Measure the extension of the spring

with the metre stick.

Repeat the procedure by adding more

weights and recording the extension

each time.

Record your results in a table, as shown.

Weight

(N)

Extension

(cm)

Now draw a graph of Extension versus weight placed on the spring.

The graph should look like this,

Block

10.5g

10.5g

Weights

Pan

Spring

Metre

stick

The graph is a straight line through

(0,0). This means that the extension is directly proportional to the force applied to it.

Mandatory experiment: To show that solids

expand when heated.

Put the ball through the hoop, to check

that it fits through the hoop.

Heat the ball for 30 seconds with a Bunsen

burner.

Try to fit the ball through now.

It cannot be done.

The solid metal ball has expanded with the

heat.

Mandatory experiment: To show that liquids

expand when heated

Heat the flask as shown.

The water will expand up the tube.

The water level in the tube will fall if

the flask is cooled, as it will contract.

Mandatory experiment: To show that gases

expand when heated

Heat the flask as shown.

The air in the flask will expand out

through the top of the tube.

If the tube is held under the water, the

expanded air can be seen bubbling out.

If the flask is allowed to cool, the air in

the flask will contract and water will be

sucked into the flask.

Mandatory experiment: To compare the

conductivity of various metals

Set up the apparatus as shown.

A thumbtack is attached with wax to

each of four metal strips with wax.

A Bunsen flame is placed at ‘x’ and the

four strips are heated evenly.

The thumbtack which falls first

indicates the best conductor.

0 0

Weight on the spring

Extension

(cm)

Flask

filled

Heat

Wooden ring

Metal

s

x

Mandatory experiment: To show that water

is a poor conductor.

Fill a test tube with water.

Hold an ice cube at the bottom and

heat the mouth with a Bunsen burner.

The water at the mouth of the test

tube will be boiling but ice cube will

not melt for a long time.

This is because the water is a poor

conductor.

Mandatory experiment: To show convection

in water

Heat the water as shown.

The hot water rises as a convection

current and the dye goes with it.

The dye makes the convection current

visible.

Mandatory experiment: To show convection

in a gas

The candle creates an updraft

(convection current) of hot air.

The hot air rises and leaves through the

chimney on the left.

Cold air is drawn in from outside,

through the chimney on the right, to

replace it.

This creates a convection current.

The smoke allows this current to be

seen by an observer.

Mandatory experiment: Light travels in

straight lines.

Set up the apparatus as shown.

The ray box emits a beam of light.

Place a ruler beside the beam to prove

that it is straight.

Bunsen

Dye

Coloured

water

rises

Box with glass front

Smoke

Candle

Ruler

Light beam Ray

box

Mandatory experiment: To show that light

can be reflected.

Set up the apparatus as shown.

The ray box emits a beam of light.

Place a small mirror in front of the

beam.

The direction of the beam will change.

The light beam has been reflected.

Mandatory experiment: To demonstrate the

use of a simple periscope.

Mirror 1 reflects the light to mirror which

then reflects the light to the observer’s eye.

The net result is that an observer can see over

other objects.

Experiment: To show the magnetic field of a

bar magnet using iron filings.

Place a bar magnet on a bench.

Cover it with a sheet of paper.

Sprinkle iron filings over the sheet.

The filings will line up along the

magnetic field lines.

The magnetic field of the magnet has

become ‘visible’ (see diagram).

Mirror Light beam Ray box