hkdse exam guide(english)

Contents

1 Introduction to HKDSE 1

Part I Public examination

2 Types of questions in the HKDSE exam paper 4

3 General exam skills 6

4 Skills in answering MCQs 10

5 Skills in answering essay questions 11

6 Skills in plotting graphs 13

7 Skills in drawing biological diagrams 14

8 Skills in studying biology 16

Part II School-based assessment (SBA)

9 About SBA 20

10 Basic experimental techniques 21

11 Skills in writing investigation reports 25

New Senior Secondary Mastering Biology 1 Oxford University Press 2014 (Second Edition)

HKDSE (Hong Kong Diploma of Secondary Education) examination is a public assessment aiming

to assess the attainment of candidates who have completed the 3-year senior secondary course.

A Mode of assessment

HKDSE examination in Biology and Combined Science (Biology) comprises two components:

public examination and school-based assessment (SBA).

Biology

Public examination SBA

Paper 1 Paper 2

Curriculum coverage Compulsory part Elective part Whole

Assessment tasks Section A: Multiple-choice questions

(36 marks)

Structured questions

(40 marks)

Practical related

tasks

Section B: Short questions, structured

questions and an essay

question (84 marks)

Number of questions

to be attempted All 2 out of 4

Duration 2 h 30 min 1 h S5 & S6

Weighting 60%

(Section A: 18%; Section B: 42%) 20% 20%

Combined Science (Biology)

Public examination (one paper only) SBA

Curriculum coverage Whole Combined Science (Biology) Whole

Assessment tasks Section A: Multiple-choice questions (24 marks) Practical related

tasks Section B: Short questions, structured questions and an essay

question (56 marks)

Number of questions

to be attempted All

Duration 1 h 40 min S5 & S6

Weighting 40% (Section A: 12%; Section B: 28%) 10%

11 IInnttrroodduuccttiioonn ttoo HHKKDDSSEE


B The reporting system

HKDSE makes use of standards-referenced reporting (SRR) () of assessments. The

candidates level of performance will be reported as five levels (15), with 5 being the highest.

A performance below Level 1 will be designated as Unclassified (U). The Level 5 candidates with

the best performance are awarded a 5**, and the next top group of candidates are awarded a 5*.

Each level has a set of descriptors () to describe what a typical candidate at this level is

able to do. Details of the descriptors and samples of candidates performance of different levels in

the past HKDSE examinations can be found at the HKEAAs website.

http://www.hkeaa.edu.hk/en/hkdse/assessment/subject_information/ category_a_subjects/hkdse_subj.html?A2&2&5

1

2

3

4

5

5*

5**


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1 Multiple-choice questions (MCQs)

For Biology, there will be 36 MCQs in Paper 1 Section A.

For Combined Science (Biology), there will be 24 MCQs in Section A of the paper.

Each question scores 1 mark.

2 Short questions

Each short question scores about 27 marks.

There are various types of short questions. Some examples are shown below.

a Fill-in-the-blanks

b Matching

In addition to the above types of short questions, some short questions begin with diagrams,

photographs, graphs or tables of data, which are followed by a few questions.

Column 1 Column 2

Mitochondrion ________ A. Encloses the cytoplasm

B. The site of energy release during respiration

Nucleus ________ C. Controls activities of the cell

D. Supports and gives shape to the cell

Cell wall ________ E. Contains organelles

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Amino acids are made up of carbon, hydrogen, oxygen and (a) ______________. Each amino

acid molecule contains an amino group and a (b) _____________ group. A (c) _____________

is formed when two amino acids combine together. It can combine with more amino acids to form

a long chain called the (d) ______________ .


For each cell structure listed in column 1, select from column 2 one phrase that correctly

describes its function. Put the appropriate letter in the space provided. (3 marks)


3 Structured questions

Each structured question scores about 712 marks.

Structured questions are usually divided into parts (a), (b) and (c), etc. Each part may be

divided into smaller parts (i), (ii) and (iii), etc.

4 Essay questions

For both Biology and Combined Science (Biology), there will be an essay question in the exam

paper. It scores about 1012 marks.

In the total mark of the essay, 3 marks are awarded for effective communication.


The diagram below represents a cross section of a flower.

(a) Name structure P and state its function. (2 marks)

(b) Using the letters in the diagram, state where

(i) meiotic cell division takes place. (2 marks)

(ii) fertilization takes place. (1 mark)

(c) State the fate of structures P, Q, R, S and U after fertilization. (5 marks)


Compare the prophase in mitosis and first meiotic division. In what way does the difference

in the prophase of first meiotic division affect the products of meiotic cell division?

(11 marks)


1 Time allocation

* depends on the mark of each question

Do the easiest questions first to build up your confidence. Do not spend too much time on

answering a difficult question. Either give it up or save it for the last.

2 Understanding command words in questions

Before answering a question, you should look for the command word in the question. It tells you

what you should answer. Below are some common command words in exam questions.

Command word Point to note Example of exam question

Calculate () Remember to show the working steps and give the answer a right

unit.

According to the information given,

calculate the rate of water absorbed by

the plant.

Comment () You need to present an informed opinion.

Comment on the significance of the

relationship between the structures for

gas exchange and water transport in

terrestrial flowering plants.

Subject Biology Combined Science (Biology)

Exam paper Paper 1

Section A

Paper 1

Section B Paper 2 Section A Section B

Mark 36 marks 84 marks 40 marks 24 marks 56 marks

Duration 2 h 30 min 1 h 1 h 40 min

Suggested

time

allocation

Answering whole

section 30 min 1 h 40 min 50 min 20 min 65 min

Checking whole

section 5 min 15 min 10 min 5 min 10 min

Answering ONE

question 50 s 310 min* 25 min 50 s 310 min*

33 GGeenneerraall eexxaamm sskkiillllss


Command word Point to note Example of exam question

Compare () Give both similarities and differences. Try to use

comparative words like larger,

smaller, etc.

Compare the structures of a bacterial

cell and a yeast cell.

Contrast () Give the differences only. Contrast the processes of mitosis and meiosis.

Deduce () Deductions must be made based on the information given.

Based on the results of the cross,

deduce which phenotype is recessive.

Describe () No explanation is required. Describe how insulin can bring about a decrease in blood glucose level.

Determine () Your answer should be based on the information given.

According to the data given, determine

the concentration of the insecticide at

which 30% of mosquitoes are killed.

Discuss () Give arguments for and against an issue and provide explanations.

Discuss the pros and cons of

producing human insulin by genetic

engineering.

Distinguish () Give the difference between two things.

Distinguish between food-borne

infection and food poisoning.

Explain / Account for () Give reasons. Explain / Account for the increase in the length of a potato strip that has

been put into distilled water for one

hour.

Give / State () No explanation is required. Give / State two functions of proteins in the human body.

Identify () Give the name and make sure the spelling is correct.

Using the dichotomous key given,

identify animals A and B.

Label () Make sure the spelling is correct. Label the cells shown in the photomicrograph.

Name () Make sure the spelling is correct. Name the type of cell division occurring in the gamete-producing

cells in human ovaries.

Outline () No detail is required. Describe the major steps in recombinant DNA technology and

outline their principles.

Suggest () Put forward your ideas. Suggest two preventive measures that we can take to reduce the risk of

contracting dengue fever.


3 Following the instructions

You must follow the instructions to answer the questions. Below are some examples of instructions.

Instruction What to do?

Using the letters in the diagram, Answer with the letters provided in the

diagram, not the names.

With reference to the photomicrograph, Use the photomicrograph / diagram provided

to arrive at the answer. Referring to the diagram,

State one other cause of Give another cause that is different from the

one stated in the question.

Use a genetic diagram to show the result. You must include a genetic diagram.

Explain your answer without using a genetic diagram. On the contrary, DO NOT use a genetic

diagram to arrive at your answer. Deduce, with reasons, the genotype of

Marks will not be awarded for genetic diagrams.

4 Communicating effectively

In answering structured questions and essay questions, express your ideas systematically and

logically. Make good use of linking words to link different ideas.

For example:

Command word Linking words

Describe (about a graph) Between and / From to

Outline the steps Firstly Secondly Thirdly Finally

Give examples of For example / This includes / such as

Contrast however / while / whereas /

In contrast / On the contrary

Explain / Account for Since / Because So / Hence / Thus / Therefore / As a result


5 Avoiding common mistakes

a Spelling mistakes

When doing fill-in-the-blanks, or when you are asked to name, identify or label a

certain structure, correct spelling is required. The key words in long answers must

also be spelt correctly. Below are some commonly misspelt words.

Correct Wrong Correct Wrong

amnion amino nuclei nucles

dietary fibre diary fibre pancreas pancrease

gastric juice gastic juice phloem pholem

membrane membrance prey pray

night blindness night blindless vertebrate vertibrate

b Inappropriate use of words

Do not confuse words with similar spellings or pronunciations. For example, the pupil of the

eye constricts, not contracts, under strong light.

c Omitting titles, headings or units

Remember to give your drawing, graph or table an appropriate title or heading. For

calculation, assign a correct unit to the value obtained.

Under strong light,

the pupil contracts.

the pupil constricts.


1 If you are CERTAIN with the answer

put a beside the question and then skip the question for checking.

2 If you are UNCERTAIN with the answer

put a ? beside the question to remind

you to pay attention during checking.

look for opposing answers. It is very likely that one of them is the correct answer.

cross out answers that mean basically the same thing. They cannot both be correct.

make a guess instead of leaving the answer blank.

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There are four major steps to help you answer essay questions.

Step 1 Read the question carefully

While you are reading the question, underline the key points and circle all the command words

(e.g. compare, explain, etc.). This can remind you what should be included in your essay.

Step 2 Organize your ideas

Use a mind map, a flow chart or a table to organize your ideas. When it is finished, check if the

ideas are coherent and systematic. Cross out any irrelevant information.

Lipids Proteins

Similar functions - components of the cell membrane

- for making hormones

- produce ATP

- as energy reserves

- for protection

Different functions - transport lipid-soluble vitamins

- as an insulator

- for making myelin sheath

- as enzymes

- as antibodies

- as haemoglobin

- for blood clotting

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Lipids and proteins are two primary food substances which are essential

to life. Compare their functions in the human body.

55


Step 3 Write your essay

Divide your essay into three parts:

Step 4 Check your essay

Check if the essay includes the necessary information. Make sure there are no spelling mistakes or

inappropriate use of words.

Lipids and proteins have many functions in the human body.

Some of the functions are similar but some are unique to each

type of biomolecule.

Both lipids and proteins are components of the cell

membrane. They are used for making hormones such as

steroids (lipids) and insulin (proteins). Both of them act as

energy reserves and can be broken down to produce ATP.

Lipids and proteins also offer protection to the body. For

example, adipose tissues around the internal organs can act as

a shock absorber and keratin in nails can provide mechanical

protection.

Lipids are a solvent for some vitamins (e.g. vitamins A and D).

They are a good insulator to reduce heat loss from the body.

Lipids are also used for making myelin sheath around nerve

fibres to speed up the transmission of nerve impulses.

Some proteins are enzymes. They can catalyse the biochemical

reactions in the body. Proteins can act as antibodies which act

against the pathogens invading the body. Some proteins are

transporters such as the oxygen carrier haemoglobin. Fibrous

proteins are involved in blood clotting. They form a network

to trap the red blood cells.

Lipids and proteins have some similar but also some different

functions in the human body. They are both important

biomolecules.

1 Introduction

Briefly describe the main

theme of your essay.

Avoid too much

background information.

2 Body

Write in paragraphs. Each

paragraph should have a

main point and the point

is explained, elaborated or

supported by evidence.

3 Conclusion

Sum up your points and

restate the main theme.


Note the following when plotting a graph:

1 Use the x-axis to denote the independent variable and y-axis to denote the dependent variable.

2 Choose a suitable scale and make full use of the graph paper.

3 Label each axis and show the units.

4 Plot each point as a small cross or dot with a sharp pencil.

5 Join the points. If two or more lines are to be drawn on the same graph, draw with different

styles (e.g. solid line versus dotted line) and label them.

6 Give a title to the graph.

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In an experiment, rats from the same mother were divided into groups A and B. Group A was fed on purified

cheese proteins, glucose, starch, fats, minerals and water. Group B was fed on the same food with additional

3 cm3 of milk each day. After 20 days, the diets of the two groups were exchanged. The average mass of the

two groups of rats from day 0 to day 50 was recorded. The results are presented on the graph below.

66 SSkkiillllss iinn pplloottttiinngg ggrraapphhss

symbol to represent the unused part of the scale (045 g). This makes the graph easier to read

5 10 15 20 25 30 35 40 45 50 time (day)

45

50

55

60

65

70

75

80

85

90

0

average mass

of rats (g)

The change in average mass of rats against time

group A

group B

y-axis is labelled and unit is shown

x-axis is labelled and unit is shown

title is given

graph paper is fully used with a suitable scale

two curves are drawn with different styles and labelled


The diagram below is poorly drawn. Can you point out the mistakes?

Points to note when drawing biological diagrams

1) Use a sharp HB pencil. Never draw in pen.

2) Draw large diagrams, occupying about two-third of a piece of A4 paper.

3) Draw with smooth single lines. Keep all parts in proportion.

4) Do not shade the diagrams. If you need to show the contrast, you may only use dots.

The denser the dots are, the deeper is the colour.

5) Draw freehand. Do not use a ruler or a pair of compasses.

6) Draw what you see from the specimen. Do not copy from books.

7) Label different parts of the drawing.

Put the labels by the sides, using labelling lines.

Labelling lines should be straight, horizontal and should not cross each other.

8) Give a title, including the name of the specimen and the power of magnification.

9) State how the section is cut if you are drawing a cut surface of a specimen, such as

longitudinal section (L.S.) or transverse section (T.S.).

10) State the direction of view if you are drawing a whole specimen, such as dorsal,

ventral or lateral view.

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There are two kinds of microscopic drawings:

1 Low-power diagrams

a They show the distribution and proportion of different tissues.

b Only outlines of structures are drawn. No need to draw individual cells.

For example:

Dicotyledonous plant root (T.S.) (10)

2 High-power diagrams

a They show the features of different types of cells.

b Draw individual cells.

For example:

Vascular tissue in dicotyledonous plant root (T.S.) (400)


Studying biology can be easy if you understand the biological concepts instead of memorizing

them by rote. Knowing some basic techniques can help you learn biology more effectively.

1 How to remember the spellings of biological terms more easily?

a By understanding prefixes and suffixes

Many biological terms are built up on Greek or Latin prefixes () and suffixes (). By

dissecting the biological terms into discrete units and knowing the meanings of the prefixes and

suffixes, you will remember their meanings and spellings more easily.

For example:

Prefix Meaning Example

an- lacking, without anaerobic (), anaemia ()

anti- against antigen (), antibody (), anticodon ()

auto- self autotroph (), autoimmune disease (),

autonomic nervous system ()

bi- two biceps (), bicuspid valve (), binary fission ()

di- two disaccharide (), dicot (),

dihybrid ()

endo- within endocrine gland (), endolymph ()

exo- outside exocrine gland (), exoskeleton ()

haem- blood haemoglobin (), haemolysis ()

hyper- above hypertonic (), hypertension ()

hypo- below hypotonic (), hypothermia ()

mono- one monosaccharide (), monocot (),

monoculture ()

photo- light photosynthesis (), phototropism (),

photolysis ()

tri- three triceps (), tricuspid valve (),

triglyceride ()

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Suffix Meaning Example

-ase enzyme amylase ( ), invertase ( ), lipase ( )

-cide killing agent fungicide (), herbicide (), pesticide ()

-lysis breaking down glycolysis (), hydrolysis (), photolysis ()

-plast living granule chloroplast (), protoplast ()

-trophic feeding autotrophic nutrition (),

heterotrophic nutrition ()

b By pronouncing words correctly

Marking down each syllable () of a word with slashes is very helpful for memorizing the

spelling. For example:

accommodation ac / com / mo / da / tion

assimilation as / si / mi / la / tion

epididymis e / pi / di / dy / mis

homeostasis ho / me / o / sta / sis

metabolism me / ta / bo / li / sm

Bear in mind that this is only a way for you to remember the spellings of the words, but not a

way for you to acquire the correct pronunciations.

c By distinguishing words with similar spellings

Make sure you are able to distinguish words with similar spellings. For example:

amino amnion

afferent efferent

cerebrum vs cerebellum

glycogen glucagon

ovule ovary

vertebrate vertebra


2 How to remember biological concepts more easily?

a By drawing flow charts through logical deductions

Start with what the question asks for, ask yourself what comes next. Answer the question you

ask. Base on your answer, ask yourself what comes next again. Repeat and you will get the

answer for questions requiring detailed explanation.

Example: What happens to the cells when a piece of onion epidermis is immersed in a

hypertonic solution?

QQ What is a hypertonic solution? AA A solution with water potential lower

than that of the cytoplasm.

QQ What happens when they differ in

water potential?

AA Water moves out of the cells through

the differentially permeable membrane

by osmosis.

QQ What happens to the cells when

they lose water?

AA The cells shrink.

QQ What happens to the cell membrane

when the cells shrink?

AA The cell membrane pulls away from

the cell wall, i.e. plasmolysis occurs.

b By using mnemonics ()

It would be easier to remember some facts or concepts if you can make associations between

different words. For example:

c By using cut-off method ()

Some biological processes are mirror images. For example:

inhalation and exhalation

accommodation of the eye to near and distant objects

constriction and dilation of the pupil

In each pair, you can focus on only one of the processes. The other process is simply the other way

round.


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The SBA of biology covers the assessment of students performances in practical related tasks

throughout the S5 and S6 school years. The tasks include laboratory work and fieldwork.

Students will be assessed in two ability areas (A and B) by their teachers.

Ability area A Ability area B

Focus on practical skills planning and reporting of

scientific investigation

Assessment

ability

organizing and performing practical work, including the use of suitable

apparatus and equipment, and the

appropriate skills in carrying out the

work

making accurate observations and measurements

identifying the problem to be

investigated and formulating a

hypothesis, where applicable

devising a plan of investigation

according to the problem identified

recording and presenting results in an

appropriate form

interpreting and discussing results, and

drawing appropriate conclusions

The table below summarizes the percentage weighting and the minimum number of assessments

required in S5 and S6 for the different areas of the SBA:

Subject Biology Combined Science (Biology)

Ability area A B A B

Weighting 8% 12% 4% 6%

Minimum number of assessment

S5 1 1 1 1

S6 1 1

Details of the SBA can be found at the HKEAAs website.

http://www.hkeaa.edu.hk/en/sba/sub_info_sba/ dse_subject.html?5

99 AAbboouutt SSBBAA


A Making a temporary mount

Making a temporary mount is the first step to prepare a specimen for microscopic examination.

Steps of making a temporary mount are shown below:

1 Place the specimen in the middle of a

slide.

2 Add 1 to 2 drops of water or stain to the

specimen.

3 Let the edge of a cover slip touch the

mounting medium.

4 Use a pair of forceps to lower the cover

slip slowly and cover the specimen.

5 Soak up excess mounting medium with

tissue paper.

6 The slide is ready for microscopic

examination.

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B Free-hand sectioning

Free-hand sectioning () is the simplest method to prepare a thin section for a temporary

mount. Steps of free-hand sectioning are shown below:

1 Moisten both the razor blade and the

specimen.

2 Hold the specimen as shown below. Rest

the razor blade on the tip of the forefinger.

Adjust the position of the forefinger to

control the thickness of the section.

3 Cut the specimen by sliding the razor

blade rapidly and smoothly towards

yourself. Repeat the steps to prepare a

number of sections.

4 Put all the sections into a Petri dish of

water. Use a paintbrush to select the

thinnest section for examination.


C Microscopic examination

1 Place the microscope on the bench with

good illumination. Rotate the nosepiece

and select the low-power objective.

2 Look through the eyepiece. Adjust the

angle of the mirror to reflect light towards

the centre of the stage.

3 Adjust the condenser and the

diaphragm until the light is sufficient

and even.

4 Clip a prepared slide onto the stage. Watch

the stage from the side and lower the body

tube by turning the coarse adjustment knob

until the objective nearly touches the slide.

5 Look through the eyepiece again.

Slowly raise the body tube by turning

the coarse adjustment knob until the

image of the specimen becomes clear.

6 Turn the fine adjustment knob until the

image is in focus.

Skip this step if the

microscope has a

built-in light source.


D Using a pipette

1 Rinse the pipette with distilled water

followed by the liquid to be transferred.

2 Insert the pipette filler into the pipette.

Squeeze the pipette filler. Use another

hand to hold the pipette.

3 Insert the pipette into the liquid to be

transferred. Release the filler slowly

until the pipette is filled to about 2 cm

above the graduation mark.

4 Remove the pipette filler. Cover the mouth

of the pipette by your forefinger.

5 Release your finger to control the flow

until the meniscus of the liquid sits on

the graduation mark.

6 Transfer the liquid to another container.

Release the liquid. Touch the pipette tip

against the side of the container to release

the last drop of liquid.

conical flask

liquid transferred


When you observe something about the natural world that you do not understand, you may carry out

investigations and try to find out the answer. How to carry out a scientific investigation is discussed

in detail in the textbook (Bk 1A, Ch 1, p. 711). After performing the investigation, you should

write a report to share what you have done and what you have discovered with other people. Below

is an example to show how to write an investigation report.

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IInnvveessttiiggaattiioonn

Peter bought some bread. He put it on a table but forgot to eat it. After a week, he

found some bread mould growing on the bread surface. He wondered if light affected the

growth of bread mould on bread. He carried out an investigation of it with the following

set-ups.

After a week, Peter put a transparency with a grid on the bread and counted the number of

squares with bread mould in both set-ups.

In set-up A, the number

of squares with bread

mould is 15.

In set-up B, the number

of squares with bread

mould is 10.


An investigation report usually includes the following:

1 Date

2 Aim

It gives the aim of the investigation.

Example: To find out whether light affects the growth of bread mould on bread.

3 Introduction

a Problem to investigate

Example: Does light affect the growth of bread mould on bread?

b Hypothesis

This part states the hypothesis of the investigation and the prediction based on the design of the

investigation. It should be noted that hypotheses are NOT needed in investigations which do NOT

require the explanation of observations (like Peters investigation).

c Principle behind the design of the investigation

This part includes:

a brief description of the rationale of the design

identification of the independent and dependent variables, and ways of manipulating and

measuring the variables

the controlled variables

Example:

Independent variable Dependent variable Controlled variables

Variable Presence of light Number of squares with

bread mould on the

bread

Kind of bread, air

temperature, humidity,

etc.

Ways of

manipulating and

measuring the

variable

Keep a slice of bread in

a light-proof box and

keep another slice of

bread in a transparent

box

Put a transparency with

a grid on the bread and

count the number of

squares with bread

mould

the critical assumptions made, if any

Example: The two slices of bread in the two set-ups are identical.


4 Procedure

This is an account of what you have done during the investigation. It should be concise, precise and

presented logically.

5 Results

There are different ways to present the results, e.g. drawing tables, plotting graphs, drawing

biological diagrams, etc.

a Drawing tables

In a table, the data of the independent and dependent variables should be clearly put side by

side for easy comparison.

Example:

b Plotting graphs (Refer to p. 13 for the skills in plotting graphs.)

c Drawing biological diagrams (Refer to p. 14 for the skills in drawing biological diagrams.)

Conditions Number of squares with bread mould

Without light 15

With light 10

Points to note when writing Procedure

1) Write in reported speech, i.e. past passive voice.

2) Number the steps, rather than describing all the steps in a single paragraph.

3) State the quantities of the apparatus and the materials used.

4) Use diagrams or tables whenever appropriate.

5) State any precautions to be taken.

6) Do not repeat the details of a step when the step is just repeated with

different kinds / amounts of materials.


6 Discussion

In this part, you should evaluate how valid the investigation is and recognize trends and patterns in

the data.

7 Conclusion

This part includes the conclusion drawn from the findings with regards to the aim of the

investigation.

Example: Light slows down the growth of bread mould on bread.

It is not necessary to give further explanations, which are not tested by the experiment.

Points to note when writing Discussion

1) State the limitations of the experimental design.

2) Suggest sources of error in the investigation and their influence on the

accuracy of the results obtained.

3) Consider any unusual observations and assess their significance.

4) Give possible explanations for unexpected results.

5) Suggest improvement for further work.

Next time I should repeat the

experiment with more bread to

increase the reliability of the

results.


Below is the investigation report written by Peter. There are many mistakes in the report. Can you

point them out?

Name: Peter Chan Class: 5A Class no.: 3

Date of investigation: 1292014

Aim

To study the growth of bread mould on bread

under different conditions.

Introduction

(a) Problem to investigate

Does light affect the growth of bread mould on

bread?

(b) Hypothesis

Bread mould does not grow in the presence of light.

(c) Principle behind the design of the investigation

Independent variable: Number of bread mould

Dependent variable: Light

Procedure

I put a slice of bread into two different boxes. One

of the boxes is a light-proof box and the other is a

transparent box. I put the set-ups under light.

After some time, I recorded the growth of bread

mould on the two slices of bread.

Only the effect of light

was studied in the

investigation.

Peters investigation

does not need an

explanation of

observation. Therefore

a hypothesis is not

required in this case.

1) Steps should be

numbered.

2) Reported speech

should be used.

3) The duration of the

experiment should

be clearly stated.

1) Variables are

wrongly stated.

2) Controlled variables

and assumptions

should be

mentioned.


without light with light

num

ber

of s

quare

s w

ith

brea

d m

ould

on t

he

brea

d

5

10

15

0

Results

The following are the results of the experiment:

Conditions Number of squares with bread

mould on the bread

Without light 15 cm

With light 10 cm

1) The units are

wrong.

2) The units, if any,

should be put in the

heading of the

column, not in the

boxes.

It is not necessary to

draw a graph for this

investigation as the

graph does not help

analyse the data.


Discussion

Much less bread mould grew on the slice of bread

under light, showing that light can inhibit the

growth of bread mould. This is because the

ultraviolet light in the light can kill the spores of the

bread mould.

As the difference in the number of squares with

bread mould in the two set-ups is large, the results

are accurate and reliable.

Conclusion

Light can prevent the growth of fungi because the

ultraviolet light can kill the spores of the fungi.

1) the ultraviolet light

in the light can kill

the spores of the

bread mould is a

new hypothesis, not

a fact.

2) Further tests should

be suggested to test

this hypothesis, e.g.

block the ultraviolet

light in the light and

carry out a similar

investigation again. 1) The reason for the judgment of the accuracy and

reliability of the experimental results is wrong.

2) As only one measurement is taken, we cannot say

that the results are reliable. Thus, this report lacks a

critical analysis of the data obtained.

The conclusion is over

generalized (applying

the finding to all

fungi) and contains

irrelevant explanation

(the role of ultraviolet

light is a new

hypothesis).

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