UG3DVV%DWFK Prefacesisquarenet.com/.../pdf/International/IGCSE_Biology.pdf · 2016-08-22 · Concise IGCSE Biology Study Guide | Unit 1.1: Characteristics of Living Organisms 1 Characteristics

Preface

Written by experienced educators from Singapore, Concise IGCSE Biology Study Guide covers all of the IGCSE specifications in a concise manner. Using straight forward language, appropriate visual illustrations and practice questions at the end of every chapter to support the biology student, this study guide is an ideal resource for class or independent study.

218 O Level IGCSE Biology 3rd Pass Batch 3 03/08/15

Authors’ Profile

Mr Jason Soh has taught Biology at the Junior College level for more than ten years. In this time, he has developed effective strategies to help his students achieve high scores in their GCE A-Level Biology examinations. Having graduated with honours in the subject, Jason also holds a Master in Science as well as a Postgraduate Diploma in Education (PGDE) from the National Institute of Education, Singapore. Today, Jason continues to help students get high grades as a full-time private tutor specialising in Biology. Jason can be contacted at [email protected].

Mr Tan Wei Xiang graduated from the National University of Singapore (NUS) with a Bachelor of Science (Honours). For the past seven years, Mr Tan has taught A-Level Biology to many exam candidates and helped International Baccalaureate students in various private schools. Mr Tan effectively caters to the different learning needs of his students through his approach in Biology education. He is focused on establishing deep clarity in biological concepts, sustaining student interest and promoting thinking skills to effectively answer difficult questions. Currently, Mr Tan continues to share his experiences with students and help them achieve distinctions in their studies.


Characteristics and Classification of Living Organisms Unit 1.1: Characteristics of Living Organisms 1 Key idea 1 Life functions 1 Unit 1.1: Practice Questions 2

Unit 1.2: Diversity and Classification of Living Organisms 4 Key idea 1 Examples of different groups of organisms 4 Key idea 2 Concept and use of a classification system 7 Key idea 3 The binomial system (binominal nomenclature) 9

Unit 1.3: Simple Keys for Identification 9 Unit 1.2: Practice Questions 10

Organisation and Maintenance of the Organism Unit 2.1: Cell Structure and Organisation 15 Key idea 1 The cell theory 15 Key idea 2 Structures of a plant cell and an animal cell 16 Unit 2.1: Practice Questions 17

Unit 2.2: Levels of Organisation 24 Key idea 1 Examples of specialized cells 24 Key idea 2 Tissues and organs 25 Unit 2.2: Practice Questions 26

Unit 2.3: Size of Specimens 32 Key idea 1 Calculating magnification and size of biological specimens 32 Unit 2.3: Practice Questions 33

Unit 2.4: Movement in and out of Cells 37 Key idea 1 Diffusion 37 Key idea 2 Active transport 40 Key idea 3 Osmosis 41 Unit 2.4: Practice Questions 44

Unit 2.5: Enzymes 54 Key idea 1 Mode of action of enzymes 54 Key idea 2 Specificity of enzymes 55 Key idea 3 Features of enzymes 56 Key idea 4 Factors affecting the rate of enzyme-catalyzed reactions 56 Key idea 5 Applications of enzymes in everyday life 58 Unit 2.5: Practice Questions 59

Unit 2.6.1: Nutrition in Living Organisms 68 Key idea 1 Features of carbohydrates 68 Key idea 2 Features of lipids 70 Key idea 3 Features of proteins 71 Key idea 4 Food test 72 Key idea 5 Principal source and importance of different types of nutrients 73 Key idea 6 Food additives 75

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Unit 2.6.2: Plant Nutrition 76 Key idea 1 Investigations of the factors required for photosynthesis 77 Key idea 2 The process of photosynthesis in land plants 80 Key idea 3 Limiting factors in photosynthesis 82 Key idea 4 Leaf structure 83 Key idea 5 Mineral requirements of plants 85 Unit 2.6: Practice Questions 86

Unit 2.6.3: Animal Nutrition 98 Key idea 1 Human alimentary canal 98 Key idea 2 The role of teeth in mechanical and physical digestion 101 Key idea 3 Adaptation of the small intestine for absorption of nutrients 103 Key idea 4 Assimilation of nutrients by the liver 105 Key idea 5 Malnutrition 106

Unit 2.7.1: Transport in Plants 107 Key idea 1 Transport of Water in Flowering Plants 107 Key idea 2 Transpiration pull 110 Key idea 3 Factors affecting the rate of transpiration 111 Key idea 4 Distribution of xylem and phloem tissues in a dicotyledonous plant 112 Key idea 5 Translocation 114

Unit 2.7.2: Transport in Humans 115 Key idea 1 Human heart 115 Key idea 2 Experiment to investigate the effect of physical activity on pulse rate 117 Key idea 3 Coronary heart disease 118 Key idea 4 Blood 119 Key idea 5 Arteries, veins and capillaries 120 Unit 2.7: Practice Questions 123

Unit 2.8: Respiration 142 Key idea 1 Types of respiration 142 Key idea 2 Role of anaerobic respiration of yeast in food production 143 Key idea 3 Gas exchange 143 Key idea 4 Mechanism of gas exchange in humans 146 Key idea 5 Effects of physical activity on the rate and depth of breathing 147 Unit 2.8: Practice Questions 149

Unit 2.9: Excretion in Humans 159 Key idea 1 The kidneys 159 Key idea 2 The liver 162 Unit 2.9: Practice Questions 163

Unit 2.10: Coordination and Response 167 Key idea 1 The human nervous system 167 Key idea 2 A simple reflex arc 167 Key idea 3 Action of antagonistic muscles 168 Key idea 4 Structure and function of the eye 169 Key idea 5 Hormones 171 Key idea 6 Coordination in plants 173 Key idea 7 Homeostasis 174 Key idea 8 Drugs 176 Unit 2.10: Practice Questions 179

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Development of the Organism and the Continuity of Life Unit 3.1 Reproduction 186 Key idea 1 Asexual reproduction 186 Key idea 2 Sexual reproduction 189 Key idea 3 Sexual reproduction in plants 189 Key idea 4 Sexual reproduction in humans 193 Key idea 5 Sexual fertilization and development of the foetus 197 Key idea 6 Labour and birth 199 Key idea 7 Methods of birth control and sexually transmissible diseases 200 Unit 3.1: Practice Questions 203

Unit 3.2: Growth and Development 217 Key idea 1 Environmental conditions required for seed germination 217 Unit 3.2: Practice Questions 220

Unit 3.3: Inheritance 225 Key idea 1 Chromosomes 225 Key idea 2 Nuclear division 226 Key idea 3 Monohybrid inheritance 226 Key idea 4 Variation 228 Key idea 5 Selection 230 Key idea 6 Genetic engineering 230 Unit 3.3: Practice Questions 232

Relationships of Organisms with one another and with their Environment Unit 4.1: Energy Flow 242 Key idea 1 Non-cyclical nature of energy flow 242

Unit 4.2: Food Chains and Food Webs 242 Key idea 1 Ecological organisations 242 Key idea 2 Energy losses between trophic levels 243 Key idea 3 Ecological pyramids 244 Unit 4.1 & 4.2 Practice Questions 246

Unit 4.3: Nutrient Cycles 254 Key idea 1 The water cycle 254 Key idea 2 The carbon cycle 255 Key idea 3 The nitrogen cycle 256 Unit 4.3: Practice Questions 257

Unit 4.4: Population 262 Key idea 1 Factors affecting the rate of population growth 262 Key idea 2 Social implications of human population size 265 Unit 4.4: Practice Questions 266

Unit 4.5: Human Influences on the Ecosystem 272 Key idea 1 Agriculture 272 Key idea 2 Pollution 273 Key idea 3 Conservation 276 Unit 4.5: Practice Questions 278

Answers 283

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1Concise IGCSE Biology Study Guide | Unit 1.1: Characteristics of Living Organisms

Characteristics and Classification of Living Organisms1

Unit 1.1: Characteristics of Living OrganismsThere is no one definition of life that is accepted by all scientists. Most biologists agree that living organisms are able to perform certain functions. These functions are characteristic of life and can be used to determine whether the given object is living, dead or non-living.

Life functions

ŵŵ Nutrition – the taking in of nutrients which are organic substances and mineral ions, containing raw materials or energy for growth and tissue repair, absorbing and assimilating them.

ŵŵ Excretion – the removal from organisms of toxic materials, the waste products of metabolism (e.g. cellular respiration) and substances in excess of requirement.

ŵŵ Respiration – the chemical reactions that break down nutrient molecules in living cells to release energy.

ŵŵ Sensitivity – the ability to detect or sense changes in the environment (stimuli) and make responses.

ŵŵ Reproduction – the processes that make more of the same kind of organisms.

ŵŵ Growth – a permanent increase in size and dry mass by an increase in cell number or cell size or both.

ŵŵ Movement – the action by an organism or part of an organism causing a change of position or place.

Key Idea 1


2 Unit 1: Characteristics and Classification of Living Organisms

Unit 1.1: Practice Questions

Multiple Choice Questions

1. The following list shows some important characteristics: (i) Respiration (ii) Reproduction (iii) Excretion (iv) Growth

Which are important characteristics of living things?A (i) and (ii) B (i) and (iii)C (i), (iii) and (iv) D All of the above

2. Which of the following life functions is not essential for the survival of living organisms?A Respiration B ReproductionC Excretion D Growth

3. Which of the characteristics refers to the ability of organism to detect or sense changes in the environment and make responses?A Sensitivity B ReproductionC Nutrition D Movement

4. Which characteristic refers to the removal of toxic metabolic waste products from the tissue cells?A Defecation B ReproductionC Nutrition D Excretion

5. Which of the following is not an important characteristic of plants as living organisms?A Movement B ReproductionC Nutrition D Excretion

6. How can a student best determine if an unknown object is living or non-living?A based on whether there is the presence of organs of ingestionB based on whether the organism is able to produce movementC based on whether the organism can respire to produce energyD based on whether the organism can produce waste products

7. Which process ensures the continued survival of a species?A Movement B ReproductionC Nutrition D Excretion


3Concise IGCSE Biology Study Guide | Unit 1.1: Practice Questions

8. Which statement is false?A Reproduction is not as essential for survival compared to respirationB Breathing refers to the exchange of gases between the lungs and surroundingsC The removal of undigested and unabsorbed matter is known as excretionD Growth refers to a permanent increase in size and dry mass of an organism

9. Which organ in the human body is not correctly paired to its specific function?A The lungs are important for respirationB The kidneys are important for excretionC The eyes are important for sensitivityD The legs are important for nutrition

10. Which characteristic involves chemical reactions that break down nutrients to release energy?A Respiration B ReproductionC Nutrition D Excretion

11. Which characteristic involves a change of position of an organism?A Movement B ReproductionC Nutrition D Excretion

12. Which characteristic shows that the organism can take in nutrients and use them to produce energy and make new cells and tissues?A Movement B ReproductionC Nutrition D Excretion

Essay Questions

1. Distinguish between the following terms:(a) egestion and excretion [2 marks](b) respiration and breathing [2 marks](c) secretion and excretion [2 marks]

2. Describe and explain four important characteristics of living things. [8 marks]



Unit 1.2: Diversity and Classification of Living OrganismsThere are millions of different kinds of living organisms. To help in the understanding of relationships among living organisms, there is a need to classify living organisms into groups based on similar (or common) features. The more similar two organisms are, the more closely related they are thought to be.

Examples of different groups of organisms

Group of organisms Common features

1. Vertebrates ŵŠ Animals with vertebral columnŵŠ Five classes – fish, amphibians, reptiles, birds and

mammals

(a) Bony fish ŵŠ Bony endoskeletonŵŠ Swim bladderŵŠ Skin with scales

(b) Amphibians ŵŠ Moist permeable skinŵŠ External fertilizationŵŠ Aquatic larval stage

(c) Reptiles ŵŠ Impermeable scaly skinŵŠ Internal fertilizationŵŠ Soft-shelled eggs

(d) Birds ŵŠ FeathersŵŠ Internal fertilizationŵŠ Hard-shelled eggsŵŠ Homeothermic

(e) Mammals ŵŠ HairŵŠ Mammary glandsŵŠ Internal fertilizationŵŠ Homeothermic

Key Idea 1


5Concise IGCSE Biology Study Guide | Unit 1.2: Diversity and Classification of Living Organisms


2. Flowering plants ŵŠ Reproduce by seeds

ŵŠ Seeds enclosed in an ovary

ŵŠ Two sub-classes – monocotyledons and eudicotyledons

(a) Monocotyledons (e.g. grasses and lilies)

ŵŠ Embryo with one seed leaf

ŵŠ Leaves with parallel veins

ŵŠ Vascular bundles scattered in stems

(b) Eudicotyledons (e.g. trees, shrubs and herbaceous plants)

ŵŠ Embryo with two seed leaves

ŵŠ Leaves with net veins

ŵŠ Vascular bundles arranged in a ring in stem

3. Arthropods ŵŠ Hard, firm external skeleton (cuticle) encloses bodies

ŵŠ Segmented bodies

ŵŠ Flexible jointed limbs between segments for movement

ŵŠ Four classes – insects, crustaceans, arachnids and myriapods

(a) Insects (e.g. butterflies, beetles, mosquitoes and houseflies)

ŵŠ Bodies segmented into distinct head, thorax and abdomen regions

ŵŠ Three pairs of limbs (but no limbs on abdominal region)

ŵŠ Compound eyes

ŵŠ One pair of antennae

ŵŠ Typically two pairs of wings

ŵŠ Water proof cuticle

(b) Crustaceans (e.g. crabs, shrimps and water fleas)

ŵŠ Compound eyes

ŵŠ Typically a pair of jointed limbs on each segment for movement

ŵŠ Limbs on head segments modified to form antennae (communication) or specialized mouth parts (feeding)




(c) Arachnids (e.g. spiders, ticks, scorpions and mites)

ŵŠ Bodies divided into two regions – cephalothorax and abdomen

ŵŠ Four pairs of limbs on cephalothorax for reproduction or predation

ŵŠ Typically possess simple eyes

(d) Myriapods (e.g. centipedes and millipedes)

ŵŠ Possess a head and segmented body with no distinction between thorax and abdomen

ŵŠ A pair of limbs on each body segment

ŵŠ Segments added as organism grows

4. Annelids (e.g. earthworms, lugworms and ragworms)

ŵŠ Elongated, cylindrical and segmented bodies

ŵŠ Each segment contain identical sets of organs except the front end

ŵŠ Segments typically contain bristles (chaetae) for movement

ŵŠ Alimentary canal, nerve cord and main blood vessels run whole length of body

5. Nematodes (e.g. hookworms, pinworms and round worms such as C. elegans)

ŵŠ Circular unsegmented body tapered at both ends

ŵŠ Free-living in soil or as parasites of plants and animals

6. Molluscs (e.g. snail, slugs, mussels, octopuses and oysters)

ŵŠ Muscular foot for movement

ŵŠ Most possess a shell

ŵŠ Simple ‘lungs’ or gills for gaseous exchange


7Concise IGCSE Biology Study Guide | Unit 1.2: Diversity and Classification of Living Organisms

Concept and use of a classification system

ŵŵ A widely used classification system places every known organism in one of five large groupings known as kingdoms which are:

(i) Monera (ii) Protoctista (iii) Fungi (iv) Plant and (v) Animal.

Kingdom Common features

Monera ŵŠ Single cell (unicellular) organismsŵŠ Lack nucleusŵŠ Examples: bacteria and blue-green algae

Protoctista ŵŠ Single cell (unicellular) organismsŵŠ Contain nucleusŵŠ May contain chloroplast (photosynthesis)ŵŠ Examples: Euglena, Amoeba and Paramecium

Fungi ŵŠ Made up of thread-like hyphaeŵŠ Contain many nuclei throughout cytoplasmŵŠ Some species are parasitesŵŠ Examples: mushrooms, toadstools, yeast and mould

Plant ŵŠ Multicellular organimsŵŠ Contain cellulose cell wallŵŠ Contain chloroplast (photosynthesis)ŵŠ Examples: algae, mosses, ferns, conifers and flowering plants

Animal ŵŠ Multicellular organimsŵŠ Ingest solid foodŵŠ Internal digestionŵŠ Examples: worms, insects, fish, amphibia, reptiles, birds,

mammals, etc.

ŵŵ The organisms within each kingdom share many broad characteristics but there is also considerable diversity or differences among them.

ŵŵ Each kingdom is subdivided into smaller groups showing higher degrees of similarities.

ŵŵ Species is the smallest group where the members share the greatest number of similarities.

ŵŵ Closely related species are grouped into a genus (plural: genera).

Key Idea 2



ŵŵ Related genera are grouped into a family; families into an order, orders into a class, classes into a phylum (plural: phyla); phyla into a kingdom.

ŵŵ The members of a species are so similar biologically (e.g. anatomy, physiology and behaviour) that they share genetic information and reproduce more individuals like themselves.

ŵŵ Note: There are other classification systems (e.g. cladistics based on RNA / DNA sequencing data).

grizzly bear black bear giant panda red foxalbert

squirrelcoralsnake sea star

KINGDOM Animalia

PHYLUM Chordata

CLASS Mammalia

ORDER Carnivora

FAMILY Ursidas

GENUS Ursus

SPECIES Ursus arctos

A hierarchial classification system


9Concise IGCSE Biology Study Guide | Unit 1.3: Simple Keys for Identification

The binomial system (binominal nomenclature)

ŵŵ A naming system (nomenclature) assists scientists to express the differences and similarities.

ŵŵ The binomial system of naming species is a “two-parts” system showing the genus and species.

ŵŵ The two names used are the genus name (always written in uppercase) and the species name (lowercase)

ŵŵ The language used in the naming system is Latin and it was first devised by Carolus Linneaus in the 18th century.

Unit 1.3: Simple Keys for Identificationŵŵ Once the main characteristics of a group are known, a dichotomous key may be used to

identify an unfamiliar organism.

ŵŵ The dichotomous key system is a written set of choices, each involving two statements, that leads to the name of an organism.

ŵŵ It can also be used to assign an organism to its specific group (e.g. class, genus or species) in a classification system.

Key Idea 3

dry skin?

hair?

opposablethumbs?

bipedal?

no

yes

no

no

noyes

yes

yes

1

2

3

4

salamander

lizard

tiger

gorilla

human

A dichotomous key system


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UG3DVV%DWFK Prefacesisquarenet.com/.../pdf/International/IGCSE_Biology.pdf · 2016-08-22 · Concise IGCSE Biology Study Guide | Unit 1.1: Characteristics of Living Organisms 1 Characteristics