Membership of the CDC Ad Hoc Committee on the Development of A-Level Biology Curriculum

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CONTENTS

Membership of the CDC Ad Hoc Committee on the Revision of A-Level Biology Syllabus

i

Membership of the CDC Ad Hoc Committee on the Development of A-Level Biology Curriculum

ii

Membership of the HKEA Sixth Form Biology Subject Committee iii

Membership of the Joint CDC and HKEA Working Group on the Development of A-Level Biology Curriculum and Assessment Guide

iv

Preamble v

I. Aims and Objectives 1

II. Curriculum Framework

A. Organisation 5

B. Time Allocation 7

C. Teaching Sequence 9

D. Content 16

III. Learning and Teaching 77

IV. Assessment

A. Formative assessment and summative assessment 85 B. School-based assessment and public examinations 86

C. Guiding principles for assessment 87

D. Assessment in schools 88

E. Public examination 93

Appendix: Reference books 95

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Membership of the CDC Ad Hoc Committee on the Revision of A-Level Biology Syllabus

(January 2000 – July 2001)

Convenor: Senior Curriculum Development Officer, Education Department (Mr. CHAN Pui-tin)

Members: Ms. CHEN Hui

Dr. CHOW King-lau

Senior Inspector, Education Department (Mr. FUNG Chuen-po)

Mr. HO Kam-moon

Dr. LUI Chung-wai, Kevin Mr. NG Yau-keung

Subject Officer, Hong Kong Examinations Authority (Mrs. TANG TSUI Sau-mei)

Mr. TSANG Kai-man

Dr. WONG Sze-chung, Raymond Ms. YAU Suk-yin, Grace

Secretary: Curriculum Development Officer, Education Department

(Mr. SO Chi-shing)

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Membership of the CDC Ad Hoc Committee on the Development of A-Level Biology Curriculum

(Since August 2001)

Convenor: Senior Curriculum Development Officer, Education Department (Mr. CHAN Pui-tin)

Members: Ms. CHEN Hui

Mr. CHEUNG Kin-lee Dr. LUI Chung-wai, Kevin Mr. LUI Kwok-hung Mr. NG Yau-keung

Subject Officer, Hong Kong Examinations Authority (Mrs. TANG TSUI Sau-mei)

Dr. WONG Sze-chung, Raymond Ms. YAU Suk-yin, Grace

Secretary: Curriculum Development Officer, Education Department

(Mr. SO Chi-shing)

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Membership of the HKEA Sixth Form Biology Subject Committee

Chairperson: Prof. YIP Din-yan

Vice chairperson: Dr. YUNG Hin-wai, Benny

Members: Mr. CHAN Pui-tin Dr. CHAN Wing-kuen

Ms. CHENG Lai-yun (until 31 August 2001) Mr. CHOW Chi-lam (until 31 August 2001) Dr. CHOW King-lau

Dr. CHU Lee-man

Mr. CHUI Hing-wa (since 1 September 2001) Mr. FUNG Chuen-po (until 31 August 2001) Mr. HO Kwok-pui (since 1 September 2001) Mr. LEE Yeung-chung (since 13 October 2001) Mr. LI Ping-fai (since 1 September 2001) Mr. LI Siu-wah (until 31 August 2001) Dr. LUI Chung-wai

Ms. LUNG Lai-ching (until 31 August 2001) Mr. MA Hing-tak (since 1 September 2001) Mr. MAN Wai-hin (until 31 August 2001) Ms. MOK Pui-ling (since 1 September 2001) Mr. NG Wing-ming, Denny

Mr. NG Yau-keung, Benjamin

Mr. O’TOOLE K Desmond (since 13 October 2001) Mr. SO Chi-shing (since 1 September 2001) Dr. SO May-ling (until 31 August 2001) Mr. TANG Chi-yin (until 31 August 2001) Dr. VRIJMOED Lilian (until 31 August 2001) Dr. WONG Kong-chu (since 1 September 2001) Mr. WONG Yuk-hing (since 1 September 2001) Dr. YIP Wing-kin

Secretary: Subject Officer, Hong Kong Examinations Authority

Mrs. TANG TSUI Sau-mei

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Membership of the Joint CDC and HKEA Working Group on the Development of A-Level Biology Curriculum and

Assessment Guide

(Since August 2001)

Convenor: Senior Curriculum Development Officer, Education Department (Mr. CHAN Pui-tin)

Members: Mr. CHEUNG Kin-lee Dr. LUI Chung-wai Mr. LUI Kwok-hung Mr. MA Hing-tak Mr. MAR Shek-shing Ms. MOK Pui-ling Mr. NG Wing-ming Mr. WONG Yuk-hing Prof. YIP Din-yan

Secretaries: Subject Officer, Hong Kong Examinations Authority (Mrs. TANG TSUI Sau-mei)

Curriculum Development Officer, Education Department

(Mr. SO Chi-shing)

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PREAMBLE

This Curriculum and Assessment Guide is one of the series jointly prepared by the Hong Kong Curriculum Development Council (CDC) and the Hong Kong Examinations Authority (HKEA). It forms the basis for learning and teaching of the subject curriculum as well as for setting public assessments. The issue of this one single document on curriculum and assessment guide aims at conveying a clear message to the public that public assessments are an integral part of the school curriculum and promoting the culture of “assessment for learning” to improve learning and teaching.

The CDC is an advisory body giving recommendations to the Hong Kong Special Administrative Region Government on all matters relating to curriculum development for the school system from kindergarten to sixth form. Its membership includes heads of schools, practising teachers, parents, employers, academics from tertiary institutions, professionals from related fields or related bodies, representatives from the HKEA and the Vocational Training Council, as well as officers from the Education Department.

The HKEA is an independent statutory body responsible for the conduct of the Hong Kong Certificate of Education Examination and the Hong Kong Advanced Level Examination. The governing council of the HKEA includes members who are mainly drawn from the school sector, tertiary institutions, government bodies, professionals and persons experienced in commerce and industry.

This Curriculum and Assessment Guide is recommended by the Education Department for use

in secondary schools. The subject curriculum developed leads to appropriate examinations

provided by the HKEA. In this connection, the HKEA has issued a Handbook as a supplement

to provide information on the format of the public examinations of the various subject

curricula (such as the proportion of multiple-choice questions and open questions) and the

related rules and regulations.

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Both the CDC and HKEA will keep the subject curriculum under constant review and evaluation in the light of classroom experiences and students’ performance in the public assessments respectively. All comments and suggestions on the Curriculum and Assessment Guide may be sent to:

Chief Curriculum Development Officer (Science) Education Department

4/F, 24 Tin Kwong Road Kowloon

Hong Kong

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I. AIMS AND OBJECTIVES

Aims

The A-Level Biology Curriculum aims to provide learning experiences through which students will acquire or develop the necessary biological knowledge and understanding, scientific process skills, values and attitudes, for their personal development, for coping with a dynamically changing society and for contributing towards a scientific and technological world.

1. For their personal development, students will be able to 1.1 observe objectively and critically;

1.2 enquire, think and reason scientifically and creatively;

1.3 solve problems through informed judgements and decisions;

1.4 be acquainted with the language of science and be equipped with the skills in communicating ideas in biology-related contexts; and

1.5 apply biological knowledge and understanding to develop positive values and attitudes towards a healthy lifestyle.

2. For coping with a changing society, students will be able to

2.1 relate and apply biological knowledge and understanding to everyday life and to the needs of a changing society;

2.2 develop and sustain an attitude of curiosity to investigate and explore; and

2.3 develop an interest in, and enjoyment of, the study of the living world so as to prepare themselves to become life-long learners in the related fields of science and technology.

3. For contributing towards a scientific and technological world, students will be able to 3.1 develop an awareness of the relationships between organisms and their

environment, and the effect of human activities on these relationships;

3.2 deepen their respect for all forms of life and their respective habitats ;

3.3 develop an attitude of contributory responsibility, including a strong sense of commitment to conserve, protect and maintain the quality of all environments for future generations; and

3.4 develop an earnest concern for biological issues in personal, social, economic,

environmental and technological contexts.

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Objectives

The general objectives listed below are to be achieved through the course of study of biology at A-Level as a whole. The objectives are categorised into three domains: knowledge and understanding, scientific process skills, and values and attitudes. Throughout the course of studying the biology curriculum, students will acquire the necessary knowledge, skills and attitudes under various biology-related contexts. Specific learning objectives will be highlighted in the section.

A. Knowledge and Understanding

Students will acquire knowledge and develop understanding of:

1. the nature of biology;

2. biological terms, biological facts, biological concepts and principles;

3. biological practical techniques;

4. the applications and uses of biology in everyday life;

5. the implications of biology for society and the environment;

6. current issues and developments in biology; and 7. the historical development of biological concepts.

Acquire or develop

biological knowledge and understanding, scientific process skills,

values and attitudes.

Personal development

Cope with a changing

society

Make contributions towards a scientific and

technological world

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B. Scientific Process Skills

Students will acquire or develop the following skills so that they can study biological phenomena through the scientific process:

1. developing scientific thinking and problem-solving skills;

2. recognising biological problems; such problems are often characterised by the presence of a range of interacting variables;

3. planning and performing investigations; formulating working hypotheses and devising tests for them, using controls where appropriate;

4. searching, collecting and organising information from various sources;

communicating and presenting them in a clear and logical form; and evaluating and applying them to solve problems in familiar and unfamiliar situations;

5. analysing and interpreting data, and extrapolating from them;

6. observing and describing objects and phenomena accurately;

7. interpreting drawings and photographs of biological structures;

8. formulating generalisations in the light of both first-hand and second-hand evidence;

9. using instruments and apparatus to the limits of accuracy appropriate to a given problem; and

10. performing common laboratory techniques and handling chemicals, instruments, apparatus and biological materials carefully and safely.

C. Values and Attitudes

Students will develop the following values and attitudes:

1. an interest and enjoyment in studying living organisms and their interrelationships;

2. a responsible regard for both the living and non-living components of the environment;

3. ethical behaviour;

4. a critical and inquiring mind;

5. an objective attitude towards evidence;

6. a positive attitude in discussing biological issues in personal, social, economical, environmental and technological contexts;

7. an awareness that the body of biological knowledge is not static; and that experimental and investigatory work are important for its advancement;

8. an awareness of the need for appropriate safety procedures;

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9. an awareness of both the usefulness and limitations of hypotheses in making predictions and explaining biological phenomena; and

10. a desire for critical evaluation of the consequences of the applications of science

and recognising their responsibilities to conserve, protect and maintain the quality

of all environments for future generations.

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II. CURRICULUM FRAMEWORK

A. Organisation

This curriculum serves as a continuation of the CDC Biology Curriculum for S4-5. With careful consideration of students’ prior knowledge and everyday experiences, it is designed to cover major aspects of biology, along with its social and technological relationships.

There are thirteen sections in this biology curriculum. Each of Sections 1 – 12 consists of two major parts: an Overview and a table of contents which is organised into three columns:

Learning objectives, Possible learning and teaching activities, and Expected learning outcomes. Section 13 provides the suggestions on the treatment of practical works.

(a) The overview

This part introduces the main theme and foci of each section. It suggests the overarching expected learning outcomes of the section. It also tries to make plain any major relationships with the other topics of this Biology Curriculum so that different sections can be studied with proper integration.

(b) The table of contents

(1) Learning objectives – this column lists out the areas in biology that students are expected to learn. Through these learning areas students may acquire or develop the skills and attitudes which are listed on page 3. These learning objectives provide a basic framework upon which the learning experiences and teaching activities can be developed.

(2) Possible learning and teaching activities – this column suggests activities that can be done by either the students or the teachers to enable students to achieve the learning objectives. The list includes a wide range of activities, such as questioning, discussions, debates, practical works, investigations, information searching and project works, etc. The duration for each activity varies, and teachers should allow sufficient time for students to develop the specific skills.

Teachers should exercise their professional judgement in selecting some of the

suggested activities or other relevant activities to enhance biology learning in

suitable contexts, and to meet the interest and abilities of their students.

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(3) Expected learning outcomes – this column lists out a range of learning outcomes, with different levels of abilities, which can be demonstrated by students in relation to the learning objectives. In most cases, only the learning outcomes with the highest cognitive ability (e.g. review, evaluate, relate, etc.) are listed. It is expected that students can also demonstrate other learning outcomes with lower cognitive abilities (e.g. state, point out, outline, etc.). Students can use these outcomes as the basis for self-assessment. Teachers can also use these outcomes to set assessment activities for checking the progress of learning and teaching.

Together with the Overview and the Learning objectives listed in the first column, the

Expected Learning Outcomes listed in the third column form the basis for the public

examination. For the examination requirement of practical skills and abilities, teachers and

students should refer to Section 13 in the curriculum framework and the Handbook for

A-Level Biology Teacher Assessment Scheme issued by the Hong Kong Examinations

Authority for details. The sequence of presentation of topics in this guide should not be

regarded as a fixed teaching order. Individual topics should be studied as integral parts of

the whole curriculum, and not as separate entities. The biological structures and processes,

for example, should be considered and understood in the context of the whole organism where

appropriate and not in isolation.

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B. Time Allocation

The A-Level Biology Curriculum is divided into thirteen sections. With a time allocation of eight 40-minute periods each week, a total of 362 periods in Secondary 6 and 7 should be enough to cover the whole curriculum, including practical work. An estimate of the number of periods required for each section is shown below to provide some guidance on the weighting to be placed on individual sections.

No. of periods

Section 1 The Cell 44

1.1 Chemical constituents 1.2 Cell structure

1.3 Transport of substances in and out of the cell 1.4 Enzymes

Section 2 Energetics 32

2.1 Photosynthesis 2.2 Chemosynthesis 2.3 Respiration

Section 3 Genetics and Evolution 46

3.1 Genetics 3.2 Evolution

Section 4 Variety of Life and Relations of Organisms with their Environment

38 4.1 Variety of life

4.2 Classification 4.3 Ecology

Section 5 Human Activities and the Environment 22

5.1 Human impact on the environment

5.2 Human responsibility for environmental conservation

Section 6 Health and Diseases 30

6.1 Some factors affecting health

6.2 Transmission of pathogens and prevention of infection 6.3 Defence against pathogens

6.4 Some non-infectious diseases

Section 7 Nutrition 18

7.1 Modes of nutrition

7.2 Nutrients required by photosynthetic plants

7.3 Heterotrophic nutrition

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Section 8 Gas Exchange and Transport 38

8.1 Gas exchange 8.2 Transport

Section 9 Support and Movement 20

9.1 Support in animals 9.2 Movement in animals 9.3 Support in plants 9.4 Movement in plants

Section 10 Sensitivity, Response and Coordination 28 10.1 Detection of environmental conditions in mammals

10.2 Nervous coordination in mammals 10.3 Hormonal coordination in mammals

10.4 Response to the environment in flowering plants

Section 11 Homeostasis 16

11.1 Homeostasis 11.2 Water balance

11.2 Regulation of body temperature 11.3 Regulation of blood glucose level

Section 12 Continuity of life, Growth and Development 30 12.1 Reproduction

12.2 Growth and development

Section 13 Practical work (subsumed in the teaching periods suggested for Sections 1-12.)

Total: 362

(Equivalent to 241 hours)

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C. Teaching sequence

The order of teaching the different parts of the curriculum will depend very much on the teachers’ individual preference and approach to the subject. Teachers may find the following information helpful in the planning of their own teaching schedules. The major relationship between sections is summarised in the flow chart below. Some suggested teaching sequences are also given in the pages that follow.

The Major Relationship Between Sections

Section 1 The Cell

Section 2 Energetics Section 3

Genetics and Evolution

Section 4 Variety of Life and Relations of Organisms with their

Environment

Section 5 Human Activities and the Environment

Section 6 Health and Diseases Section 7 Nutrition

Section 8 Gas Exchange and

Transport

Section 9 Support and Movement

Section 10 Sensitivity, Response and Coordination

Section 11 Homeostasis Section 12

Continuity of Life, Growth and

Development

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Suggested Teaching Sequence A

*The Functioning of Living Organisms comprises of Nutrition; Gas Exchange and Transport; Sensitivity, Response and Coordination; Support and Movement; Homeostasis; and Continuity of Life, Growth and Development.

Genetics and Evolution The Cell

Nature and Action of Gen

e

Mitosis and Meiosis

Variety of Life and Relations of Organisms with their Environment

Human Activities and the Environment

Energetics

Health and Diseases

The Functioning of Living Organisms*

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Suggested Teaching Sequence B

*The Functioning of Living Organisms comprises of Nutrition; Gas Exchange and Transport; Sensitivity, Response and Coordination; Support and Movement; Homeostasis; and Continuity of Life, Growth and Development.

Genetics and Evolution Energetics

Health and Diseases

The Functioning of Living Organisms* The Cell

Nature and Action of Gen

e

Mitosis and Meiosis

Variety of Life and Relations of Organisms with their Environment

Human Activities and the Environment

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Suggested Teaching Sequence C

*The Functioning of Living Organisms comprises of Nutrition; Gas Exchange and Transport; Sensitivity, Response and Coordination; Support and Movement; Homeostasis; and Continuity of Life, Growth and Development.

The Cell

Nature and Action of Gene

Mitosis and Meiosis

Genetics and Evolution

Variety of Life and Relations of Organisms with their Environment

Human Activities and the Environment

Energetics

Health and Diseases

The Functioning of Living Organisms*

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Suggested Teaching Sequence D

*The Functioning of Living Organisms comprises of Nutrition; Gas Exchange and Transport; Sensitivity, Response and Coordination; Support and Movement; Homeostasis; and Continuity of Life, Growth and Development.

The Cell

Nature and Action of Gene

Mitosis and Meiosis

Genetics and Evolution Variety of Life and Relations of Organisms with their Environment

Human Activities and the Environment

Energetics

Health and Diseases

The Functioning of Living Organisms*

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Suggested Teaching Sequence E

*The Functioning of Living Organisms comprises of Nutrition; Gas Exchange and Transport; Sensitivity, Response and Coordination; Support and Movement; Homeostasis; and Continuity of Life, Growth and Development.

Variety of Life

The Functioning of Living Organisms* The Cell

Energetics

Genetics and Evolution

Health and Diseases

Human Activities and the Environment

Relations of Organisms with their Environment

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Suggested Teaching Sequence F

*The Functioning of Living Organisms comprises of Nutrition; Gas Exchange and Transport; Sensitivity, Response and Coordination; Support and Movement; Homeostasis; and Continuity of Life, Growth and Development.

The Cell Variety of Life

Energetics

Human Activities and the Environment Genetics and Evolution

Health and Diseases

The Functioning of Living Organisms*

Relations of Organisms with their Environment

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D. Content

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Section 1 The cell

Section 1 aims to provide students with an extended understanding of the roles of the biological molecules, and to reinforce the concept that the cell is the fundamental unit of structure and function in living organisms.

Having learnt about the importance of carbohydrates, fats and proteins as food substances in S4-5, students will have a further understanding of the different roles of these biological molecules in living organisms. Together with the study of the roles of nucleotides and nucleic acids, students are prepared to the biochemical approach to the study of Energetics (Section 2), and Nature and action of the gene (Section 3).

The structure-function relationships of cells, cell organelles and membranes are studied. This paves the way to the understanding of the intricacies of energy conversion processes in Section 2, making it possible to relate some of these metabolic processes to the structures of a cell.

Knowledge of transport across membranes helps students to understand Gas exchange in organisms (Section 8), Absorption and transport of water and mineral salts in flowering plants (Section 8) and Transmission of nerve impulse (Section 10). Coupled with topics on Chemical constituents and Enzymes, this section would also lead to a more thorough understanding of Digestion and Absorption in Heterotrophic nutrition (Section 7).

Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

1.1 Chemical constituents

1.1.1 Carbohydrates

 the chemical structure of glucose as:  Explore students’ ideas about the chemical composition of carbohydrates.

 Use models or audiovisual materials to show the structure of carbohydrates.

 recognise the chemical structure of glucose.

O

OH H

OH OH

OH

H

H H H

CH2OH

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Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

 the types of carbohydrates: monosaccharides (hexose and pentose), disaccharides (sucrose and maltose) and polysaccharides (cellulose, starch and glycogen).

 Ask students to list different types of carbohydrates.

 give examples of the different types of carbohydrates.

 the formation of glycosidic bond.  Use ball-and-stick model to illustrate the formation of glycosidic bond.

 state that monosaccharides can be linked by glycosidic bond.

 the function of carbohydrates as an energy source:

glucose as an immediate energy source, starch and glycogen as storage compounds.

 Explore students’ prior knowledge on the functions of carbohydrates.

 state the functions of carbohydrates.

 the function of carbohydrates as structural materials:

cellulose as component of cell wall.

 the functions of starch and cellulose in relation to their molecular structures, with a brief reference to

- and - linkages.

 appreciate that a small difference in molecular structure could lead to a great difference in function.

 state the importance of carbohydrates in organisms.

1.1.2 Lipids

 the basic components of triglycerides.  Explore students’ ideas about the chemical composition of lipids.

 state the basic components of triglycerides.

 the function of lipids as an energy source:

triglycerides as storage compounds.

 Explore students’ prior knowledge on the functions of lipids.

 state the functions of lipids.

 the function of lipids as structural components:

phospholipids as components of membranes.

 the function of lipids as regulatory substances, with an awareness of cholesterol as a precursor of steroid hormones (e.g. sex hormones) and vitamin D.

 Search for information on the sources and importance of cholesterol.

 state the importance of lipids in organisms.

1.1.3 Proteins

 amino acids as the monomers that make up proteins.  Explore students’ ideas about the chemical composition of proteins.

 describe the structure of proteins.

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Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

 the chemical structure of amino acid as:  recognise the chemical structure of amino acid.

 peptide bonds and polypeptide chains.

 the 3-dimensional conformation of proteins: its ultimate dependence upon amino acid sequence and its functional significance.

 Use models or audiovisual materials to show the structure of proteins.

 explain the relationship between amino acid sequence and the 3-dimensional conformation of proteins.

 describe the functional significance of the 3-dimensional conformation of proteins.

 the functions of proteins: as structural components, e.g. in cell membrane and cytoplasm.

 relate the functions of proteins to their chemical structure.

 the roles of proteins as enzymes, hormones and antibodies.

 state the importance of proteins in organisms.

 Use food tests (e.g. Benedict’s test, iodine test, grease spot test, Sudan test and biuret test) to identify food substances in a range of biological materials, including solutions, suspensions and sections. These tests can be done quantitatively whenever appropriate.

 Design and perform investigations to identify and analyse the occurrence of food substances in foods and other biological materials.

1.1.4 Nucleotides and nucleic acids

 the basic components of nucleotides.

 mononucleotides: ATP (adenosine triphosphate) as an energy carrier.

 Use models or audiovisual materials to show the structure of DNA.

 state the basic components of nucleotides.

 outline the roles of mononucleotides,

dinucleotides and polynucleotides in metabolism.

 dinucleotides: NAD (nicotinamide adenine dinucleotide) as a coenzyme.

 polynucleotides: RNA (ribonucleic acid) and DNA (deoxyribonucleic acid).

C COOH

H2N

H R

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Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

 distinguish between carbohydrates, triglycerides, proteins and nucleic acids according to their chemical structures.

1.1.5 Inorganic components

 the presence of inorganic ions in cells.  Discuss the possible roles of inorganic ions in cells.

 Discuss the possible benefits of drinking mineral water or isotonic drinks.

 give examples of inorganic ions in cells.

 appreciate the importance of inorganic ions.

 the biological significance of water in relation to its properties.

 Discuss whether life can exist without water.  explain why water is important to life.

1.2 Cell structure

 the variety of cell structure and function as exemplified by the following: leaf epidermis, parenchyma, collenchyma, sclerenchyma, phloem, xylem, epithelia (squamous, ciliated and stratified), blood cells and neurones.

 Provide students with a variety of biological materials, such as sections, whole mounts, macerated plant materials, and blood smear.

Ask students to make observations using light microscope and to record them as drawings using annotation.

 Use sample drawings to illustrate the criteria of good high power drawings.

 Prepare temporary mounts of leaf epidermis (e.g. onion, Zebrina sp., Rhoeo discolor), free-hand sections of herbaceous stems and use simple staining techniques where appropriate.

 Measure cell size using a light microscope with a micrometer graticule, or other means.

 identify the special features of different types of cells.

 relate these special features to the functions of the cells.

 the ultrastructures and their functions in plant and animal cells: nucleus, cell wall, cell membrane, vacuole, chloroplast, mitochondrion, lysosome, ribosome, endoplasmic reticulum and Golgi apparatus.

 Guide students to interpret electron micrographs and work out the size of cell organelles.

 relate the structure of cell organelles to their functions.

 interpret electron micrographs and estimate the size of cell organelles.

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Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

 the fluid mosaic model of membranes.  Use a tank, ping-pong balls, pieces of foam and water to construct a fluid mosaic model of the membrane.

 use the fluid mosaic model to explain the properties and functions of membranes.

 appreciate the use and limitations of scientific models.

 the structure of prokaryotic cells and eukaryotic cells.

 Guide students to list the similarities and differences between prokaryotic cells and eukaryotic cells by examining electron micrographs.

 compare the cellular organisation of prokaryotic and eukaryotic cells.

1.3 Transport of substances in and out of the cell

 the selective permeability of membranes.

 the destruction of membranes at high temperatures and by some chemicals, e.g. chloroform, ethanol.

 Guide students to design investigations to study the effects of temperature and chemicals on membrane permeability; ask students to suggest suitable biological materials to be used for these studies.

 explain the selective permeability of membranes.

 the processes of diffusion, osmosis and active transport.

 the processes of pinocytosis and phagocytosis.

 Use materials such as the red lower epidermis of the leaves of some ornamental plants

(e.g. Zebrina sp. or Rhoeo discolor) to show plasmolysis of plant cells.

 Use materials such as the epidermis of onion scale leaves and potato tuber tissue to determine the solute potential or water potential of plant cells.

 explain how substances can move across membranes by various processes.

 turgor and plasmolysis in plant cells with reference to water potential, solute potential and pressure potential.

 use the concept of water potential to explain or predict biological phenomena.

1.4 Enzymes

 the protein nature of enzymes.

 the role of enzymes as catalysts in lowering activation energy through the formation of enzyme-substrate complex.

 state the roles of enzymes in metabolism.

 the concept of active site and enzyme specificity.

 the induced-fit model of enzyme action.

 use the concepts of active site and induced-fit model to explain the action of enzyme.

 appreciate the impermanent nature of scientific theories with reference to the development of the understanding of the nature of enzyme action.

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Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

 the effects of temperature, pH, enzyme

concentration and substrate concentration on the rate of enzymatic reactions.

 the effects of cofactors, reversible inhibitors (competitive and non-competitive) and irreversible inhibitors on the rate of enzymatic reactions.

 end-product inhibition.

 Guide students to design investigations to study the effects of different factors on the rate of enzymatic reactions. Suitable enzymes include amylase, urease, catalase, pepsin, sucrase.

(Where possible, at least some of the enzymes used should be obtained from living tissues and/or commercial products, e.g. biological washing powder and meat tenderiser.)

 describe and explain the effects of various factors on the rate of enzymatic reactions.

 the application of enzymes, e.g. biological washing powder and meat tenderiser.

 Explore students’ knowledge of the use of enzymes in everyday life.

 give examples of the applications of enzymes in everyday life.

 explain how enzymes work in household products.

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Section 2 Energetics

Respiration is the process by which energy is released in living cells through the controlled oxidative breakdown of organic food materials.

Organisms may have to synthesise these organic food materials using energy from the sun (photosynthesis) or from the oxidation of inorganic materials (chemosynthesis).

This section aims to extend students’ understanding of the concepts of energy transformation in photosynthesis and respiration. An outline of their energy conversion processes, including an insight into their interrelationship, should be discussed. But details of the metabolic pathways, names of intermediates and individual enzymes should be de-emphasised. Chemosynthesis should be stressed as a process using an alternative source of energy to light, thus forming a solitary exception to the much-accepted concept that energy needed by living organisms comes ultimately from the Sun.

This section builds on prior knowledge in Section 1: Cell structure (especially the ultrastructures of chloroplasts and mitochondria), Chemical constituents and Enzymes. It prepares students for an understanding of the role of energy in supporting physiological processes discussed in the other sections, and provides them with a foundation for the study of Energy flow and nutrient cycling (Section 4).

Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

2.1 Photosynthesis

 the importance of photosynthesis in converting light energy to chemical energy.

 Discuss what would happen to the living world if all photosynthetic organisms disappeared from the Earth.

 explain the importance of photosynthetic organisms as producers.

2.1.1 Site of photosynthesis

 the structure of dicotyledonous leaves in relation to photosynthesis.

 Ask students to collect a variety of broad leaves.

Guide them to list out the common morphological features of the leaves and relate them to

photosynthesis.

 Examine a section of a dicotyledonous leaf microscopically to study its structure in relation to photosynthesis.

 describe the adaptive features of leaves to photosynthesis.

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Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

 the structure of chloroplast as shown in electron micrographs. [Refer to Section 1.2.]

 the occurrence of different pigments in the chloroplast.

 Extract leaf pigments with extracting solvent, and separate them by paper chromatography.

 relate the structure of chloroplast to its functions in photosynthesis.

 the absorption spectra of chlorophyll pigments and the action spectrum of photosynthesis.

 Show pictures of the spectrum of white light passing through a prism and the spectrum of white light passing through a chlorophyll extract and a prism. Guide students to deduce the light absorption property of chlorophyll.

 relate the absorption spectra of chlorophyll pigments to the action spectrum of photosynthesis.

2.1.2 Photochemical reactions

 an outline of the photochemical reactions:

(1) electrons in chlorophylls are excited by light energy, without referring to photosystems I and II;

(2) energy from these excited electrons generates ATP;

 Use audiovisual materials to illustrate the photochemical reactions.

 Discuss the importance of the photochemical reactions.

 outline the main steps of photochemical reactions.

 explain the importance of photochemical reactions.

 outline the principle of photophosphorylation.

 relate biochemical pathways of photosynthesis to their sites in cells.

(3) photolysis of water provides hydrogen for the reduction of NADP (nicotinamide adenine dinucleotide phosphate) and oxygen gas is released.

 Discuss how the establishment of photosynthesis might have led to the evolution of aerobic organisms.

 Construct a flow chart to show the process of photochemical reactions.

2.1.3 Carbon fixation

 an outline of the Calvin cycle to show that:

(1) carbon dioxide is accepted by a 5-C compound to form two molecules of a 3-C compound;

 Read how Calvin used radioactive isotopes to trace the path of carbon atoms in photosynthesis.

 Construct a flow chart to show the process of carbon fixation.

 outline the main steps of carbon fixation.

 point out the dependence of this process to the photochemical reactions.

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Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

(2) reduction of the 3-C compound by reduced NADP to triose phosphate, some of which combine to yield hexose phosphate which is subsequently metabolised to sucrose and starch;

 describe the fates of triose phosphate.

(3) metabolism of some of the triose phosphate to provide a continuous supply of the 5-C carbon dioxide acceptor.

 that triose phosphate can be used as a substrate to produce lipids and amino acids.

2.1.4 Factors affecting the rate of photosynthesis

 the effects of light intensity, carbon dioxide concentration and temperature on the rate of photosynthesis.

 Ask students to predict the possible effects of various factors on the rate of photosynthesis.

Guide students to design and perform investigations to test their ideas.

 describe and explain the effects of various factors on the rate of photosynthesis.

 the concept of limiting factors, as exemplified by light intensity and carbon dioxide concentration.

 Perform experiments to study the factors affecting the rate of photosynthesis using a bubbler / syringe, J-tube or a data logger with oxygen or pressure sensors.

 explain the concept of limiting factors.

 the principle for maximising plant growth in greenhouse by the control of light, temperature and carbon dioxide concentration.

 Discuss how to increase the yield of plants through the design of a greenhouse.

 apply the concept of limiting factors in the design of a greenhouse.

2.2 Chemosynthesis

 the general nature of chemosynthesis using nitrifying bacteria as an example.

 Search for information on the importance of other types of bacteria in the maintenance of the ecosystem.

 realise the occurrence of chemosynthesis.

 point out the difference between chemosynthesis and photosynthesis.

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Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

2.3 Respiration

 the importance of respiration in converting chemical energy in food to chemical energy in ATP.

 define respiration.

 compare respiration and photosynthesis.

2.3.1 The sites of respiration

 the sites of the various biochemical pathways of respiration.

 state the sites of different stages of respiration.

 the structure of mitochondrion as shown in electron micrographs. [Refer to Section 1.2.]

 Use electron micrographs to show the structure of mitochondrion.

 relate the structure of mitochondrion to its function.

2.3.2 Glycolysis

 an outline of glycolysis to show:

(1) the phosphorylation of glucose;

(2) the break down of hexose phosphate to triose phosphate;

 Construct a flow chart to show the process of glycolysis.

 Read how scientists worked out the glycolytic pathway.

 describe the main steps of glycolysis.

 point out the significance of glycolysis.

(3) the conversion of triose phosphate to pyruvate with the production of reduced NAD and ATP.

2.3.3 Aerobic pathway

 the conversion of pyruvate to acetyl-CoA.

 an outline of the Krebs cycle to show:

(1) the combination of acetyl-CoA with a 4-C compound to form a 6-C compound;

 Construct a flow chart to show the aerobic pathway.

 Discuss the ways to measure the rate of aerobic respiration. Then conduct investigations to find the rate of aerobic respiration in plants and animals, e.g. germinating seeds and mealworms.

 describe the main steps of Krebs cycle.

 review the interrelationships between glycolysis, Krebs cycle and electron transport chain.

 state the importance of Krebs cycle.

(2) that the 6-C compound undergoes a series of reactions to regenerate the 4-C compound with the release of carbon dioxide;

(3) the production of reduced NAD and ATP.

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Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

 that lipids and proteins can be used to produce reduced NAD and ATP.

 the electron transport chain as a process of oxidative phosphorylation; the role of molecular oxygen as the final electron acceptor.

 point out the alternative substrates for respiration.

2.3.4 Anaerobic pathway

 the fate of pyruvate under anaerobic condition.

 the formation of lactic acid in muscle; the oxygen debt.

 the formation of ethanol and carbon dioxide in yeast.

 Design and perform investigations to find the rate of anaerobic respiration in yeast.

 Search for information on the brewing of beer and wine making.

 outline the biochemical pathways of alcoholic fermentation and lactic acid fermentation.

 suggest how the knowledge of anaerobic respiration can be used in everyday life.

2.3.5 Energy yield

 the comparison of the energy yield of aerobic and anaerobic respiration, without calculating the number of ATP produced.

 compare the energy yield of aerobic and anaerobic respiration.

2.3.6 Role of ATP

 the role of ATP in energy transfer.  explain the role of ATP in energy transfer.

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Section 3 Genetics and Evolution

Section 3 aims to link together the understanding of the principles of genetics, the nature and behaviour of chromosomes and the role of genes at the molecular level. They form the basis of current and future genetic applications.

Controversial issues related to the applications of genetics should be evaluated critically in the light of their societal and ethical implications for the future well being of humankind. The historical development of genetic concepts and ideas, progressing to some of the breakthroughs and milestones of biology, should be introduced so as to give students some insights into the nature and methods of scientific investigation. This section closes with the mechanism of evolution, which should be discussed constructively and impartially against the evidence available, pointing out the inadequacy of science to provide complete answers.

This section extends the learning of Nucleic acids in Section 1. Students should be able to relate genetics to evolution and to relate these to other pertinent sections of this curriculum such as Health and Diseases (Section 6) and Continuity of life, Growth and Development (Section 12).

Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

3.1 Genetics

 about how the experiments of Mendel, Meselson and Stahl, etc., have contributed to the

understanding of genetics.

 Read how some biologists (e.g. Mendel, Griffith, Hershey, Chase, Watson, Crick, Stahl, Meselson, Chargaff, Morgan) have contributed to our understanding of genetics.

 appreciate the historical development of genetic concepts and ideas.

 appreciate that the development of scientific theories requires creative thinking and empirical support.

 appreciate that the development of scientific knowledge is an ongoing process in which each generation of researchers gradually improves upon previous insights.

 develop insights into the methods of scientific investigation.

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Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

3.1.1 Nature and action of the gene

 the structure and chemical nature of DNA to show its role as the genetic material. [Refer to Section 1.1.4.]

 Use models or audiovisual materials to illustrate the double helical structure of DNA.

 Construct simple models of DNA using common materials (e.g. poppit beads, plasticine, cardboard, wire, pipe cleaners).

 Extract DNA (e.g. DNA spooling) using living materials.

 state the role of DNA.

 relate the structure of DNA to its role as the genetic material.

 the semiconservative nature of DNA replication:

mechanism and evidence as illustrated by the work of Meselson and Stahl.

 Use models or audiovisual materials to illustrate the semiconservative mechanism of DNA replication.

 appreciate the process involved in scientific investigation.

 the features of the genetic code.  Discuss with students how to use three letters to construct a large number of words.

 state the features of the genetic code.

 the roles of DNA and RNAs in protein synthesis.  Use models or audiovisual materials to demonstrate the roles of DNA and RNAs in protein synthesis.

 describe the process of protein synthesis.

 explain how genes determine body characteristics.

 Construct more complex models of a section of DNA and a complementary mRNA molecule (e.g.

using commercial kits).

 that genes can be turned on and off.  realise that genes can be turned on and off.

3.1.2 Structure of chromosomes

 the organisation of DNA into chromosomes in eukaryotic cells.

 Observe giant chromosomes (e.g. the salivary glands of Chironomus larvae) in squashed preparations or photomicrographs.

 distinguish between DNA and chromosomes.

3.1.3 Cell cycle

 interphase: duplication of DNA

 nuclear division

(1) Mitosis : behaviour of chromosomes at prophase, metaphase, anaphase and telophase; the significance of mitosis.

 Observe and identify the different stages of mitosis using squashed tissues, prepared slides, or photomicrographs of root tip.

 describe the process of mitosis.

 identify the different stages of mitosis.

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Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

(2) Meiosis : behaviour of chromosomes during first and second divisions of meiosis including chiasma formation; crossing over;

the significance of meiosis.

 Observe meiosis in plant and animal cells using prepared slides or photomicrographs.

 describe the process of meiosis.

 compare the processes of mitosis and meiosis.

 state and explain the significance of mitosis and meiosis.

 an outline of cytoplasmic division in animal and plant cells.

 point out that cell cycle consists of interphase, nuclear division and cytoplasmic division.

3.1.4 Inheritance of discrete characters

 monohybrid and dihybrid crosses. (The pioneer work of Mendel should be referred to.)

 backcross and test cross.

 dominance and recessiveness.

 Incomplete dominance (e.g. the colour of petals in snapdragon).

 codominance (e.g. human blood group AB).

 multiple alleles (e.g. human ABO blood groups).

 sex-linked traits (e.g. haemophilia and red-green colour blindness).

 Discuss how Mendel conceived his theories on the basis of empirical evidence.

 Study the results of monohybrid and dihybrid crosses to illustrate the patterns of inheritance.

 Use computer simulation to study genetic crosses of some organisms (e.g. Drosophila).

 Construct a pedigree of the inheritance of some human traits (e.g. ABO blood groups, tongue rolling, ear lobe of the family).

 Use chi-square test to estimate the matching between observed and expected phenotypic outcomes.

 Provide genetic problem to guide students to interpret and predict the results of genetic crosses.

 appreciate the importance of imagination and evidence in the formulation of hypotheses.

 explain and predict inheritance patterns in monohybrid and dihybrid crosses.

 state the use of backcross and test cross.

 predict the possible phenotypes of the offspring in genetic cross.

 state different patterns of inheritance from results of genetic crosses.

 linkage and crossing over.  relate linkage of genes and crossing over to

chromosomal behaviour during meiosis.

 state the significance of crossing over.

3.1.5 Discontinuous and continuous variations

 the factors contributing to variations between individuals within a species.

 discontinuous variations (e.g. tongue rolling and ABO blood groups in humans) and continuous variations (e.g. height and weight in humans).

 realise that variations occur.

 explain how mutation, meiosis and fertilisation may lead to genetic variations.

 evaluate the importance of genetic factors and environmental factors in causing variations.

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Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

 the normal distribution curve.

 the use of standard deviation as a measure of the variation of a sample.

 Collect and analyse data on continuous and discontinuous variations using appropriate statistical software.

 demonstrate statistical skills in data analysis.

 the outline of polygenic inheritance and the effects of environment on it.

 outline polygenic inheritance.

 state the effects of environment on phenotypes.

3.1.6 Mutation

 gene mutation: the effect of gene mutation on amino acid sequence (e.g. sickle-cell anaemia).

 chromosome mutation: changes in chromosome structure and chromosome number (e.g. Down syndrome).

 Display pictures showing the symptoms of some diseases caused by gene mutation and

chromosome mutation.

 Show photomicrographs of karyotypes of chromosome mutation.

 point out that mutation can take place at different levels.

 the types of mutation: spontaneous and induced mutations.

 that mutations can be enhanced by ionising radiations and chemicals. [Refer to Section 6.]

 Use available evidence to assess the nature of risks involved in exposure to mutagens.

 Discuss the precautionary measures in using X-ray in medical examination.

 Search for information on the sources of mutagenic agents and their effects on human health.

 state the different causes of mutation.

 practise ways to minimise the risk of developing mutation.

 develop a concern for the proliferation of mutagenic agents.

 significance of mutation.  explain the importance of mutation in the

mechanism of evolution.

3.1.7 Applications of genetics

 human genetics:

(1) Pedigree analysis (e.g. colour blindness).  Analyse pedigrees to trace the inheritance of some human traits.

 apply the principles of genetics in pedigree analysis.

(2) Genetic screening (e.g. detection of Down syndrome).

 Search for information on the kinds of genetic diseases that can be detected by screening test.

 appreciate the use of genetic screening in detecting some genetic diseases.

 Conduct a small survey or project on the available screening services for the detection of common genetic diseases in Hong Kong.

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Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

(3) Prenatal and postnatal counselling of genetic diseases (e.g. glucose6phosphate

dehydrogenase deficiency and thalassaemia).

 Search for information on the provision of prenatal and postnatal counselling of genetic diseases in Hong Kong.

 Visit a prenatal and postnatal genetic counselling check-up clinic.

 develop an awareness of the importance of genetic counselling.

(4) Gene therapy as a potential treatment of genetic diseases (e.g. cystic fibrosis).

 Search for information on examples of gene therapy and the prospects of gene therapy in relation to the Human Genome Project.

 appreciate the potential use of gene therapy.

(5) The implications of the Human Genome Project.

 Debate on the pros and cons of the Human Genome Project (HGP) or discuss the ethical and social concerns brought about by the HGP.

 discuss the contributions and concerns of the findings of the Human Genome Project.

 plant and animal breeding

(1) Artificial selection and breeding for selected traits to produce desirable varieties. Hybrid vigour and polyploidy.

 Use audiovisual materials to show artificial insemination and cloning.

 Search for information on selective plant breeding, e.g. miracle rice.

 Search for information on modern technological advances in the selective breeding of domestic animals, e.g. the use of sperm banks, artificial insemination, and embryo transplants.

 appreciate the application of making appropriate genetic crosses to produce progeny with desirable traits.

 explain the biological principles behind artificial selection.

(2) Cloning. [Refer to Section 12.]  Read about tissue culture in plant cloning, e.g.

orchid.

 Search for information on animal cloning.

 appreciate the application of cloning in

maintaining desirable traits in selected plants and animals.

 the outline of the principle of recombinant DNA technology and its applications.

 Use diagrams or flow charts to illustrate the principle of recombinant DNA technology.

 outline the principle of recombinant DNA technology.

 cite examples of the applications of recombinant DNA technology.

 the outline of the principle of DNA fingerprinting, and its forensic use, e.g. parentage test.

 Carry out separation of DNA or polypeptides by electrophoresis.

 Use audiovisual materials to illustrate the process of DNA fingerprinting.

 outline the principle of DNA fingerprinting.

 state the applications of DNA fingerprinting.

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Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

 Examine cases or discuss the use of DNA fingerprinting in forensic science.

 implications of genetic manipulation: the potential benefits, hazards and ethical issues.

 Debate on the pros and cons of genetic engineering or genetically modified food.

 discuss potential benefits, hazards and ethical issues related to genetic manipulation.

 appreciate that genetic engineering has made possible the development of new biotechnologies and careers.

3.2 Evolution

 the evidence of evolution: a brief assessment of fossils and homologous structures in pentadactyl limbs. The limitations and accuracy of fossil records.

 Display replicas or photographs of some fossils.

 Read about the evolutionary development of modern horse.

 evaluate the use of fossil records and homologous structures as evidence for evolution.

 point out the limitations of using fossil records.

 the presence of other evidences of evolution, e.g.

comparative anatomy, comparative biochemistry.

 develop an awareness of the other evidence of evolution.

 the mechanism of evolution: the roles of genetic variation, natural selection, and isolation in the development of new species.

 Use the development of resistance in bacteria to certain antibiotics as an example to illustrate the concept of evolution.

 Search for information on the phylogenetic significance of organisms which are considered to be “living fossils”.

 Read about the works of some biologists (e.g.

Darwin and Lamarck) and their proposed theories of evolution.

 describe the mechanism of evolution and speciation.

 evaluate the theory of natural selection.

 develop curiosity towards the origin of life.

 Discuss the validity of the theory of natural selection.

 Guide students to review the differences between scientific theories and other non-scientific modes of explanation, e.g. religious, metaphysical or philosophical, which have been a subject of considerable debate over the years.

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Section 4 Variety of Life and Relation of Organisms with their Environment

Section 4 advocates the study of organisms in relation to their natural habitats, alongside with ecological field studies, in a local context. The purpose is to give students an appreciation both of biodiversity and of the way in which organisms are adapted to survive in their habitats. It extends the knowledge acquired in S4-5 and aims to further students’ understanding of the interrelationships between organisms and between organisms and their environment. This section also introduces the binomial system of naming organisms and the concept of taxonomic hierarchy. Students are expected to have the ability to construct and use dichotomous keys to identify animals and plants based on their distinguishing external features.

Prior study of Energetics (Section 2) offers a foundation to the comprehension of energy flow and nutrient cycling. An integrated study of ecology with Human Activities and the Environment (Section 5) is conducive to the deepening of students’ respect for living organisms, their respective habitats and the environment. The concepts of Variation and Mechanism of evolution (especially natural selection) learnt in Section 3 may also be applied to explain the diversity and distribution of organisms within a habitat and in different habitats.

Learning objectives Possible learning and teaching activities Expected learning outcomes

Students should learn Students should be able to

4.1 Variety of life

 the relationship between the diversity of

organisms and the variety of their ways of life.

 to use a range of organisms found in two different local habitats (preferably, one terrestrial habitat and one aquatic habitat) to illustrate how the organisms are adapted to their habitats and ways of life.

 Use specimens or audiovisual materials to illustrate the diversity of organisms, and their ways of life.

 Study organisms (e.g. algae, ferns, gymnosperms, angiosperms including monocotyledonous plants and dicotyledonous plants, molluscs, annelids, echinoderms, cnidarians, arthropods, vertebrates) in relation to their natural habitats during field studies.

 appreciate the wonders of the living world and the ways in which organisms are adapted to their habitats during field studies.

4.2 Classification

 that modern classification is based on the phylogenetic relationships of organisms.

 state that the classification system is subject to change as new evidences appears.

Figure

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References

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