Biology F4 Experiments

Chapter 2 – Cell Structure and Cell

Organisation

Number Activity 2.1 (Observation)Pg. 9Title Preparing and examining slides

of plant cellsAim / Objective of the Study

To prepare and study slides of plant cells

Material Onion Hydrilla sp. Leaf Iodine solution Distilled water Filter paper

Apparatus Light microscope Glass slides Cover slips A pair of forceps Scalpel Dropper Mounting needle

Technique used

Prepare and stain wet mount of specimens. Observe and draw the structures of plant cells using a light microscope.

Number Activity 2.2 (Observation)Pg. 10Title Preparing and examining slides

of animal cellsAim / Objective of the Study

To prepare and study slides of animal cells

Material Methylene blue solution Iodine solution Toothpick Distilled water Cheek cells Filter paper

Apparatus Light microscope Slides Cover slips Forceps Dropper Mounting needle

Technique used

Prepare and stain wet mounts of specimens. Observe and draw the structures of animal cells using a light microscope

Movement of Substances across the

Plasma Membrane

Number Activity 3.1 (Experiment)Pg. 20Title The movement of substances

across a semi-permeable membrane

Aim / Objective of the Study

To study the movement of substances across the Visking tubing

Problem Statement

What factor influences the diffusion of substances through a semi-permeable membrane?

Hypothesis

The diffusion of molecules through a semi-permeable membrane is based on the size of the molecule

Variables Manipulated variable: Size of the solute molecules in the Visking tubing

Responding variable: Colour of the solution in Visking tubing

Fixed variable: Time, volume of solutions and surrounding temperature

Material Benedict’s solution 1% starch suspension Iodine solution 30% glucose solution Distilled water

Apparatus Visking tubing Cotton thread Test tubes

Beakers Water bath (Bunsen burner,

tripod stand & wire gauze)Technique used

Test for the presence of starch and glucose with iodine and Benedict’s solution respectively

Number Activity 3.2 (Experiment)Pg. 23Title Studying osmosis using an

osmometerAim / Objective of the Study

To demonstrate the process of osmosis using simple osmometer

Problem Statement

What substances can diffuse through a semi-permeable membrane?

Hypothesis

Osmosis takes place when water moves from a region of low solute concentration to a region of high solute soncentration across a semi-permeable membrane

Variables Manipulated variable: Concentration of solution

Responding variable: Increase in the level of sucrose solution / The level of sucrose solution in the capillary tube

Fixed variable: Concentration of sucrose solution, surrounding temperature

Material 30% sucrose solution Distilled water

Apparatus 25 cm capillary tube Visking tubing Retort stand and clamp Cotton thread Ruler Marker pen

A pair of scissors 250 ml beaker Syringe Stopwatch

Technique used

Measure and record the increase in the height of sucrose solution with a ruler.

Number Activity 3.4 (Observation)Pg. 27Title Studying the effects of

hypotonic, hypertonic and isotonic solutions on animal cells


To study the effects of hypotonic, hypertonic and isotonic solutions on animal cells (red blood cells)

Material Fresh chicken blood 0.15 M sodium chloride

solutions 0.50 M sodium chloride

solutions Distilled water Filter paper

Apparatus Glass slides Cover slips Filter papers Light microscope Test tubes Beakers Dropper

Technique used

Observe and study the effects of hypotonic, hypertonic and isotonic solutions on animal cells from the slides by using microscope

Number Activity 3.5 (Observation)Pg. 28Title Studying the effects of hypotonic,

hypertonic and isotonic solutions on plant cells


To study the effects of hypotonic, hypertonic and isotonic solutions on plant cells (cell sap of onion cells)

Material Onion bulb 0.5 M sucrose solutions 1.0 M sucrose solutions Distilled water

Apparatus Light microscope Glass slides Cover slips Razor blade / scalpel A pair of forceps Mounting needle Filter papers

Technique used

Observe and study the effects of hypotonic, hypertonic and isotonic solutions on plant cells from the slides by using microscope.

Number Activity 3.6 (Experiment)Pg. 30Title Determining the concentration

of an external solution which is isotonic to the cell sap of a plant


To determine the concentration of an external solution which is isotonic to the cell sap of a plant

Problem Statement

What is the concentration of an external (sucrose) solution which is isotonic to the cell sap of plants?

Hypothesis The concentration of the solution which is isotonic to the cell sap of plant cells has no effect on the mass, length and size of plant cells.

0.36 M sucrose solution is isotonic to the cell sap of plants

Variables Manipulated variable:

Concentration of sucrose solution

Responding variable: Length of potato strips / Mass of potato strips

Fixed variable: Volume of sucrose solution used, surrounding temperature and time

Material Fresh potato Distilled water 0.1 M sucrose solution 0.2 M sucrose solution 0.3 M sucrose solution 0.4 M sucrose solution 0.5 M sucrose solution 0.6 M sucrose solution

Apparatus Petri dishes A pair of forceps Razor blade / Sharp scalpel Cork borer Ruler 50 ml beakers Electronic scale / electronic

balance Tissue paper

Technique used

Measure the length of potato strips with ruler

Determine the percentage difference in length

Mass of potato strips with an electronic balance

Determine the percentage difference in mass

Chapter 4 – Chemical Composition of the

Cell

Number Activity 4.1 (Observation)Pg. 33Title Differentiating between

reducing and non-reducing sugars

Aim / Objective

To differentiate between reducing and non-reducing

of the Study

sugars

Material Benedict’s solution Dilute hydrochloric acid Sodium hydrogen carbonate

powder 10% glucose solution 10% sucrose solution

Apparatus Test tubes Test tube holder Beaker Dropper Bunsen burner Tripod Wire gauze

Technique used

Carry out testing for the presence of reducing sugars with Benedict’s solution

Number Activity 4.3 (Experiment)Pg. 36Title Studying the effects of

temperature on salivary amylase activity


To study the effects of temperature on salivary amylase activity

Problem Statement

What are the effects of temperature on salivary amylase activity?

Hypothesis

The rate of reaction catalysed by salivary amylase is highest at 37˚C / The optimum temperature for salivary amylase is 37˚C

Variables Manipulated variable: Temperature of medium of reaction

Responding variable: The rate of reaction catalysed by salivary amylase

Fixed variable: Volume of

saliva, volume and concentration of starch suspension and pH of medium

Material 1% starch suspension Saliva suspension Iodine solution Ice cubes Distilled water

Apparatus Beakers Test tubes Test tube rack Syringes Droppers Glass rods White tile with grooves Thermometer Bunsen burner Tripod stand Wire gauze Stopwatch

Technique used

Test the presence of starch using iodine test

Record the time taken for the hydrolysis of starch to be completed.

Number Activity 4.4 (Experiment)Pg. 39Title Studying the effects of pH

on the activity of pepsinAim / Objective of the Study

To study the effects of pH on the activity of pepsin

Problem Statement

What are the effects of pH on the activity of pepsin?

Hypothesis

An acidic medium at pH 3 is optimum for the activity of pepsin

Variables Manipulated variable: pH of medium

Responding variable:

Rate of reaction catalysed by pepsin

Fixed variable: Volume and concentration of albumen suspension, volume and concentration of pepsin solution and temperature of medium

Material Egg albumen suspension

1% pepsin solution 0.1 M hydrochloric acid 0.1 M sodium hydroxide

solution Distilled water

Apparatus Beakers Test tubes Test tube rack Droppers Glass rod Thermometer 5 ml syringes pH paper Bunsen burner Tripod stand Wire gauze Stopwatch

Technique used

Observe and record the conditions of mixtures before and after 20 minutes

Number Activity 4.5 (Experiment)Pg. 42Title Studying the effects of substrate

concentration on salivary amylase activity


To study the effects of substrate concentration on salivary amylase activity

Problem Statement

What are the effects of substrate concentration on salivary amylase activity?

Hypothesis

The rate of enzymatic reaction increases with the increase in substrate concentration until it reaches a maximum rate

Variables Manipulated variable: Substrate concentration / Concentration of starch suspension

Responding variable: Rate of reaction / Time taken for the hydrolysis of starch to be completed

Fixed variable: Enzyme concentration, pH of medium, volume of starch, volume of saliva suspension and surrounding temperature

Material 0.1% starch suspension 0.2% starch suspension 0.3% starch suspension 0.4% starch suspension 0.5% starch suspension 0.6 % starch suspension 0.1% amylase solution /

saliva suspension Iodine solution

Apparatus Syringes White tiles with grooves Test tubes Glass rod Dropper Measuring cylinder Stopwatch Beaker Thermometer Water bath (Bunsen burner,

tripod stand and wire gauze)Technique used

Test for the presence of starch using iodine test

Record the time taken for the hydrolysis of starch to be completed with a stopwatch

Number Activity 4.6 (Experiment)

Pg. 43Title Studying the effect of enzyme

concentration on the activity of salivary amylase


To study the effect of enzyme concentration on the activity of salivary amylase

Problem Statement

What are the effects of enzyme concentration on the activity of salivary amylase?

Hypothesis

The rate of enzymatic reaction increases with the increase in enzyme concentration as long as there are no other factors limiting the rate of reaction.

Variables Manipulated variable: Enzyme concentration

Responding variable: Rate of reaction

Fixed: Substrate concentration and temperature

Material 1% starch suspension 0.5% amylase solution /

saliva suspension Iodine solution Distilled water

Apparatus 5 ml of syringe 1 ml of syringe White tiles with grooves Test tubes Glass rod Dropper Measuring cylinder Stopwatch Beaker Thermometer Water bath (Bunsen burner,


Test for the presence of starch using iodine test

Record the time taken for the hydrolysis of starch to be completed with a stopwatch

Chapter 6 – Nutrition

Number Activity 6.1 (Observation)Pg. 61Title Determining the energy value in

food samplesAim / Objective of the Study

To determine the energy value in food samples

Material Peanut (whole) Plasticine Cotton wool Distilled water

Apparatus Boiling tube Thermometer (0 – 100˚C) Pin (5 – 8 cm) Bunsen burner Retort stand and clamp Wind shield Electronic balance

Technique used

Measure and determine the energy value in food samples (groundnut)

Measure the mass of the food samples by using electronic balance

Number Modify from Activity 6.1 (Observation)

Pg. 61Title Determining the energy value in

food samplesAim / Objective of the Study

To determine the energy value in food samples

Problem Statement

Which food sample has a higher energy value?

Hypothesis

Cashew nut/ Walnut has a higher energy value that goundnut

Variables Manipulated variable: Type of food sample

Responding variable: Energy value of food samples

Fixed variable: Mass of water and mass of food sample

Material Fresh peanut (whole) Fresh cashew nut / Fresh

walnut (whole) Plasticine Cotton wool Distilled water Matches

Apparatus Boiling tube Thermometer (0 – 100˚C) Pin (5 – 8 cm) Bunsen burner Retort stand and clamp Wind shield Electronic balance

Technique used

Measure and determine the energy value in different food samples

Compare the energy value in different food samples (groundnut and cashew nut / walnut)

Measure the mass of the different food samples by using electronic balance

Number Activity 6.3 (Experiment)Pg. 65Title Determining the vitamin C

content in various fruit juicesAim / Objective of the Study

To determine the vitamin C content in various fruit juices

Problem Statement

Do different types of fruit juices contain similar amounts of vitamin C?

Hypothesi Lime juice contains a higher

s concentration of vitamin C compared to pineapple juice and orange juice.

Variables Manipulated variable: Types of fruit juices

Responding variable: Volume of fruit juice needed to decolourise DCPIP solution

Fixed variable: Volume of DCPIP solution and standard concentration of ascorbic acid solution

Material 1.0% dichlorophenolindophenol (DCPIP) solution

0.1% ascorbic acid solution Freshly prepared lime juice Freshly prepared pineapple

juice Freshly prepared orange

juiceApparatus Specimen tubes

1 ml syringe 5 ml syringes with needles 50 ml beakers Gauze cloth Knife / Scalpel

Technique used

Measure and determine the volume of standard vitamin C solution needed to decolourise of a fixed volume of DCPIP.

Measure and determine the volume of juice needed to decolourise the same volume of DCPIP.

Calculate the vitamin C content of juice by comparing it with the standard vitamin C solution.

Number Activity 6.4 (Experiment)Pg. 67

Title Planning and conducting an experiment to study enzyme action on starch


To study enzyme action on starch

Problem Statement

How does the enzyme in saliva act on starch?

Hypothesis

The enzyme is saliva digest starch into a reducing sugar / The enzyme in saliva hydrolyses starch into a reducing sugar

Variables Manipulated variable: Absence or presence of salivary amylase and starch

Responding variable: Presence of reducing sugar

Fixed variable: Temperature at 37˚C, starch concentration and volume of mixture

Material 1% starch suspension Benedict’s solution Iodine solution Saliva suspension Distilled water

Apparatus 10 ml pipette 500 ml beaker Test tubes Test tube holder Test tube rack Thermometer Droppers Glass rod White tile Bunsen burner Tripod stand Wire gauze

Technique used

Confirmation test for the presence of starch using iodine solution

Confirmation test for the presence of reducing sugar using Benedict’s solution

Number Activity 6.5 (Experiment)Pg. 68Title Planning and conducting an

experiment to study the enzyme action on a protein food sample

Introduction

Albumen does not dissolve completely in water

Albumen suspension is milky in nature. After albumen is fully digested, the suspension becomes clear

Pepsin requires an acidic pH of about 2 to act at maximum rate


To study the enzyme action on a protein food sample

Problem Statement

How does the enzyme acts on protein?

Hypothesis The test tube contains albumen and pepsin solution becomes clear at the end of the experiment

An acidic medium is needed for protein digestion by pepsin

Variables Manipulated variable: Absence or presence of pepsin in albumen

Responding variable: Cloudy or clear (clarity of contents) albumen suspension after 20 minutes

Fixed variable: Concentration and volume of albumen, concentration and volume of pepsin (enzyme), concentration of hydrochloric acid, surrounding temperature at 37˚C

Material Albumen (egg-white) suspension

Dilute hydrochloric acid Pepsin suspension Distilled water

Apparatus 10 ml pipette 500 ml beaker Test tubes Test tube rack Droppers Thermometer Stopwatch Water bath (Bunsen burner,

tripod stand and wire gauze)

Technique used

Observe albumen digestion under the presence or the absence of pepsin and hydrochloric acid.

Number Activity 6.7 (Observation)Pg. 71Title Studying the movement of

substances through the Visking tubing

Aim / Objective of the StudyProblem Statement

What substances can move across the Visking tubing?

Hypothesis

Small molecules can move across the Visking tubing

Variables Manipulated variable: Contents of the Visking tubing

Responding variable: Change in colour of water sample in iodine test and Benedict’s test

Fixed variable: Temperature of water bath (37˚C), volume of solution

Material 1% starch suspension 1% glucose solution Iodine solution Benedict’s solution Visking tubing Thread Distilled water

Apparatus Boiling tube Test tubes 10 ml syringe Pipette A pair of scissors Water bath (Bunsen burner,


Confirmation test for the presence of starch using iodine solution

Confirmation test for the presence of reducing sugar using Benedict’s solution

Number Activity 6.11 (Experiment)Pg. 76Title Investigating the effect of light

intensity on the rate of photosynthesis


To investigate the effect of light intensity on the rate of photosynthesis

Problem Statement

How does light intensity affect the rate of photosynthesis?

Hypothesis The higher the light intensity, the higher the rate of photosynthesis

Variables Manipulated variable: Distance between light source and plant

Responding variable: Number of bubbles released in five minutes (rate of photosynthesis)

Fixed variable: Type and size of plant, percentage of sodium hydrogen carbonate solution and voltage of bulb

Material A few sprigs of Hydrilla sp. 1% sodium hydrogen

carbonate solution Plasticine Distilled water

Apparatus Light source (60 W bulb) 500 ml beaker Test tube Glass filter funnel Stopwatch Thermometer Meter rule Razor

Technique used

Count the number of gas bubbles released in five minute with a stopwatch

Chapter 7 – RespirationNumber Activity 7.1 (Observation)Pg. 83Title Studying the process of aerobic

respirationAim / Objective of the Study

To study the process of aerobic respiration

Material Coloured liquid Living organism (cockroach) Soda lime Petroleum jelly (Vaseline) Water

Apparatus Boiling tubes 500 ml beaker 250 ml beakers Capillary tubes

Rubber tubings Screw clips Ruler Wire gauze

Technique used

Measure and record the heights of the coloured liquids in the capillary tubes with a ruler

Number Activity 7.2 (Experiment)Pg. 85Title Investigate the process of

anaerobic respiration in yeastAim / Objective of the Study

To investigate the process of anaerobic respiration in yeast

Problem Statement

What are the products of fermentation?

Hypothesis In the absence of oxygen, yeast undergoes anaerobic respiration to produce carbon dioxide, ethanol and energy

Variables Manipulated variable: Presence of yeast

Responding variable: Changes on lime water and temperature

Fixed variable: Anaerobic condition

Material 5% yeast suspension 5% glucose solution Paraffin oil Lime water

Apparatus Boiling tubes Test tubes Thermometers Stoppers with delivery tubes Measuring cylinders Beaker

Technique used

Record and measure the changes in temperature with thermometers.

Observe the change in lime

water.

Number Activity 7.6 (Experiment)Pg. 93Title Investigating the difference

between inhaled and exhaled air in terms of oxygen and carbon dioxide contents


To investigate the difference between inhaled and exhaled air in terms of oxygen and carbon dioxide contents

Problem Statement

Are the contents of oxygen and carbon dioxide in inhaled air the same as those on exhaled air? / does inhaled air contain the same amount of oxygen and carbon dioxide as exhaled air?

Hypothesis

Inhaled air has a higher percentage of oxygen when compared to exhaled air. Exhaled air has a higher percentage of carbon dioxide when compared to inhaled air.

Variables Manipulated variable: Inhaled air and exhaled air

Responding variable: Percentages of oxygen and carbon dioxide

Fixed variable: Method of analysis

Material Potassium hydroxide solution

Potassium pyrogallate solution

Apparatus J-tube Boiling tubes Rubber tubing Ruler Washbasin

Technique used

Measure and observe the length of air columns occupied by gases in a J-tube with a ruler

Number Activity 7.7 (Experiment)Pg. 96Title Investigating the differences

between inhaled and exhaled air in terms of heat content


To investigate the differences between inhaled and exhaled air in terms of heat content

Problem Statement

Is the heat content in inhaled air the same as that in exhaled air?

Hypothesis

Exhaled air has higher heat content when compared to inhaled air

Apparatus ThermometerTechnique used

Measure and record the change in temperature with a thermometer

Number Activity 7.8 (Experiment)Pg. 97Title Studying the effects of vigorous

exercise on the breathing and heartbeat rates


To study the effects of vigorous exercise on the breathing and heartbeat rates

Problem Statement

What is the effect of vigorous exercise on the breathing and heartbeat rates?

Hypothesis Vigorous exercise increases the breathing and heartbeat rates

Variables Manipulated variable: Resting or vigorous exercise

Responding variable: Breathing rate and heartbeat rate

Fixed variable: The type and duration of exercise, gender

and age of the studentsMaterial -Apparatus StopwatchTechnique used

Count and record the number of breaths per minute and the number of heartbeats per minute

Number Activity 7.9 (Experiment)Pg. 99Title Demonstrating the effects of

cigarette smoke on lungsAim / Objective of the Study

To show the effects of cigarette smoke on lungs

Problem Statement

What are the effects of cigarette smoke on lungs?

Hypothesis

Cigarette smoke corrodes the cotton wool to change colour and contains acidic gas.

Variables -Material Cotton wool

Universal indicator Cigarettes

Apparatus U-tube Thermometer Boiling tube Retort stand and clamp Filter pump Rubber tubing

Technique used

Observe the effect of cigarette smoke on lungs and increases the temperature of the respiratory tract. Tobacco tar makes the lungs appear brownish.

Chapter 8 – Dynamic Ecosystem

Number Activity 8.3 (Experiment)Pg. 108Title Studying the intraspecific and

interspecific competitions in plants


To study the intraspecific and interspecific competitions in plants

Problem Statement

How do intraspecific and interspecific competitions affect the growth of maize and rice plants?

Hypothesis

Intraspecific competition occurs between plants of the same species. Interspecific competition occurs between plants of different species. / The greater the competition among the seedlings, the greater the effect on the height of the seedlings.

Variables Manipulated variable: Types of seedlings

Responding variable: Dry mass of seedlings / Height of seedling

Fixed variable: Quantity and types of garden soil, amount of water, intensity of sunlight, distance between each seedling and number of seedlings

Material Three seedling trays (2 m x 1 m each) with garden soil

A packet of maize seeds A packet of paddy seeds Distilled water

Apparatus Ruler Oven Compression balance Spade Waterproof paint Paintbrush

Technique used

Weight the dry mass of seedling with an electronic balance / Measure the height of seedling with a ruler

Number Activity 8.7 (Experiment) Pg. 114Title Studying the relationship of

population distribution of an organism with the changes of an abiotic factor

Aim To study the relationship of population distribution of an organism with the changes of an abiotic factor

Introduction

Pleurococcus sp. is a unicellular green alga found on the bark of trees. The population distribution ofPleurococcus sp.is affected by abiotic factors such as humidity, temperature, light intensity and aspect.

Objective of the Study

To investigate the effect of light intensity on the population distribution of Pleurococcus sp. in its habitat.

Problem Statement

What is the effect of light intensity on the population distribution of Pleurococcus sp.?

Hypothesis The population distribution of Pleurococcus sp. is highest when there is optimum light intensity

Variables Manipulated variable: Light intensity

Responding variable: Total surface are covered by Pleurococcus sp.

Fixed variable: Temperature, pH and humidity

Material PaperApparatus Quadrat measuring 10 cm x

10 cm A compass Pen Notebook

Technique used

Quadrat sampling (estimate the total surface area covered

by Pleurococcus sp.)

Number Activity 8.11 (Experiment)Pg. 119Title Studying the effects of

temperature, pH, light intensity and nutrients on the activity of yeast

Aim To study the effects of temperature, pH, light intensity and nutrients on the activity of yeast.


A) To study the effect of temperature on the activity of yeast.

Problem Statement

What is the effect of temperature on the activity of yeast?

Hypothesis

The activity of yeast is optimal at 37˚C

Variables Manipulated variable: Temperature of the water bath

Responding variable: Height of the coloured liquid in the manometer

Fixed variable: Volume of yeast suspension, pH, light intensity and time taken for the activity of yeast

Material Yeast suspension (4 g of yeast in 100 cm3 of glucose solution)

Coloured liquid Ice cubes

Apparatus Boiling tubes Beakers Measuring cylinders Glass tubes Thermometers Clips Rubber stoppers Rubber tubing Manometer tubes

Strings Ruler Stopwatch Water bath (Bunsen burner,


Measure and record the different heights of coloured liquid in the manometer with a ruler.


B) To study the effect of pH on the activity of yeast.

Problem Statement

How does pH affect the activity of yeast? / What is the effect of different pH values in the activity of yeast?

Hypothesis

The activity of yeast is optimum in an acidic medium.

Variables Manipulated variable: pH Responding variable: Height

of the coloured liquid in the manometer

Fixed variable: Volume of yeast suspension, light intensity, temperature and time taken


0.1 mol dm-3 hydrochloric acid

0.01 mol dm-3 hydrochloric acid

0.1 mol dm-3 sodium hydroxide solutions

0.01 mol dm-3 sodium hydroxide solutions

Coloured liquid pH paper distilled water

Apparatus Boiling tubes Beakers Measuring cylinders Glass tubes Clips Rubber stoppers

Rubber tubing Manometer tubes Strings Ruler Stopwatch Retort stand

Technique used



C) To study the effect of light intensity on the activity of yeast.

Problem Statement

How does the intensity of light affect the activity of yeast? / What is the effect of light intensity on the activity of yeast?

Hypothesis

The activity of yeast is higher at a lower intensity of light. / The lower the light intensity, the higher the activity of yeast.

Variables Manipulated variable: Intensity of light

Responding variable: Height of coloured liquid in the manometer

Fixed variable: Volume of yeast suspension, pH, temperature and time taken


Coloured liquidApparatus Light bulb (60W)

Boiling tubes Beakers Measuring cylinders Glass tubes Clips Rubber stoppers Rubber tubing Manometer tubes Strings Ruler Stopwatch Retort stand

Technique used



D) To study the effect of nutrients on the activity of yeast.

Problem Statement

How do nutrients affect the activity of yeast? / What is the effect of nutrients on the activity of yeast?

Hypothesis

The concentration of nutrients affects the activity of yeast. / The higher the concentration of nutrients, the higher the activity of yeast.

Variables Manipulated variable: Concentration of nutrients

Responding variable: Height of coloured liquid in the manometer

Fixed variable: Volume of yeast suspension, pH, light intensity and temperature

Material Dry yeast 5% glucose solution 10% glucose solution 15% glucose solution Distilled water

Apparatus Boiling tubes Beakers Measuring cylinders Glass tubes Clips Rubber stoppers Rubber tubing Manometer tubes Strings Stopwatch Retort stand

Technique used


Chapter 9 – Endangered Ecosystem

Number Activity 9.1 (Experiment)Pg. 127Title Comparing solid pollutants in

the air of different environmentsAim / Objective of the Study

To compare solid pollutants in the air of different environments

Problem Statement

Does the air of different environments contain the same amount of solid pollutants?

Hypothesis The air of different environments does not contain the same amount of solid pollutants. / The air from the most polluted environment has the highest amount of solid pollutants.

Variables Manipulated variable: Air from different environments

Responding variable: Amount of solid pollutants present

Fixed variable: Time and size of cellophane tape

Material Cellophane tapeApparatus Slides

Petri dish Microscope

Technique used

Observe the amounts of solid pollutants with a microscope

Number Activity 9.2 (Experiment)Pg. 128Title Investigating the level of

pollution in several different sources of water


To investigate the level of pollution in several different sources of water. Industrial area Housing area From the hill / river

Distilled water (control)Problem Statement

What is the level of pollution in several different sources of water?

Hypothesis The water sample from the housing area drainage is the most polluted.

Variables Manipulated variable: water samples from different sources.

Responding variable: Time taken for methylene blue solution to decolourise

Fixed variable: Volume of water sample, size of reagent bottles, concentration and volume of methylene blue solution

Material Methylene blue solution Water samples Distilled water

Apparatus Reagent bottles (250 ml) with stoppers

Beakers Syringes Stopwatch

Technique used

Measure and record the time taken for the methylene blue solution to decolourise by using a stopwatch

Documents

Biology F4 Experiments