pearson baccalaureate biology · pdf filesame sequence. each chapter starts with a list of the...

A Correlation of

Pearson Baccalaureate Biology

Standard Level ©2015

To the

International Baccalaureate Biology Curriculum

Standard Level & Options

A Correlation of Pearson Baccalaureate Biology, Standard Level, ©2015 to the International Baccalaureate Biology Curriculum

2 SE = Student Edition U = “understanding” – specific content concepts A = “application” – illustrative examples or significant experiments in biology history S = “skill” –practical activities or data analysis G = “guidance” – specifics and constraints to the requirements

Introduction This document demonstrates how Pearson Baccalaureate Biology, Standard Level, ©2015 meets the International Baccalaureate Biology Curriculum, at the Standard Level and Options. Pearson Baccalaureate Biology is the 2nd edition of the market-leading Pearson Baccalaureate Standard Level biology book. It completely matches the specifications of the NEW International Baccalaureate biology curriculum and gives thorough coverage of the entire course content. The program covers the two parts of the International Baccalaureate syllabus: the core and the options. Each chapter in the book corresponds to a topic or option in the IB guide, in the same sequence. Each chapter starts with a list of the Essential Ideas from the IB biology guide, which summarize the focus of each sub-topic. Pearson Baccalaureate Biology covers the course content using plain language, will all key scientific terms explained in the eBook glossary. The same terminology seen in IB examinations is present in all worked examples and questions. A popular feature of the book is the different colored boxes interspersed throughout each chapter to enhance learning, such as:

• Nature of Science promotes concept-based literacy as students recognize similar themes emerging across different topics.

• International-mindedness provides examples of global, environmental, political and socio-economics considerations.

• Laboratory Work indicates links to ideas for lab work and experiments that support learning in the course and prepare students for assessment.

• Hints for Success provide hints on how to approach questions and identify common pitfalls in understanding, and omissions made in answering questions.

• Challenge Yourself contains open questions that encourage students to think about the topic in depth or to make detailed connections with other topics that are challenging.

Three types of questions in the text: 1. Worked examples with solution 2. Exercises at the end of each chapter 3. Chapter practice questions, mostly from previous years’ IB examinations

eBook contains the following features:

• Animations • Videos • Interactive glossary of scientific words • Teacher assessment advice • Interactive quizzes, and more



Table of Contents

Topic 1: Cell Biology ............................................................................................... 4 Topic 2: Molecular Biology ...................................................................................... 8 Topic 3: Genetics .................................................................................................. 14 Topic 4: Ecology ................................................................................................... 19 Topic 5: Evolution and Biodiversity ...................................................................... 23 Topic 6: Human Physiology .................................................................................. 26 Option A: Neurobiology and behavior ................................................................... 32 Option B: Biotechnology and bioinformatics ......................................................... 36 Option C: Ecology and conservation ..................................................................... 40 Option D: Human Physiology ................................................................................ 43



IB Biology Curriculum Standard Level & Options

Pearson Baccalaureate Biology Standard Level

Topic 1: Cell Biology 1.1 Introduction to Cells Essential Idea: The evolution of multicellular organisms allowed for cell specialization

and cell replacement. U.1 Living organisms are composed of

cells. SE: 4-5, 39

U.2 Unicellular organisms carry out all functions of life.

SE: 5-7

U.3 Cell Surface to volume is an important limitation to cell size.

SE: 8-10

U.4 Multicellular organisms have properties that emerge due to the interaction of their cellular components.

SE: 5, 10

U.5 Specialized tissues can develop by cell differentiation in multicellular organisms.

SE: 10-11

U.6 Differentiation involves the expressions of some genes and not others in a cell’s genome.

SE: 10

U.7 The capacity of stem cells to divide and differentiate along different pathways is necessary in embryonic development and also makes stem cells suitable for therapeutic uses.

SE: 10-11

A.1 Questioning the cell theory using atypical examples, including striated muscle, giant algae and aseptate fungal hyphae.

SE: 40

A.2 Investigation of functions of life in Paramecium and one named photosynthetic unicellular organism.

SE: 6-7

A.3 Use of stem cells to treat Stargardt’s disease and one other named condition.

SE: 11

A.4 Ethics of the therapeutic use of stem cells from specially created embryos, from the umbilical cord blood of a new-born baby and from an adult’s own tissues.

SE: 11





S.1 Use of a light microscope to investigate the structure of cells and tissues, with drawing of cells. Calculation of the magnification of drawings and the actual size of structures and ultrastructures shown in drawings or micrographs. (Practical 1)

SE: 25-27 (Laboratory)

1.2 Ultrastructure of Cells Essential Idea: Eukaryotes have a much more complex cell structure than prokaryotes. U.1 Prokaryotes have a simple cell

structure without compartmentalization.

SE: 12-15, 23

U.2 Eukaryotes have a compartmentalized cell structure.

SE: 15-22, 23

U.3 Electron microscopes have a much higher resolution than light microscopes.

SE: 8, 15

A.1 Structure and function of organelles within exocrine gland cells of the pancreas and within palisade mesophyll cells of the leaf.

SE: 15-23

A.2 Prokaryotes divide by binary fission. SE: 14-15

S.1 Drawings of the ultrastructure of prokaryotic cells based on electron micrographs.

SE: 14, 15 (#5)

S.2 Drawings of the ultrastructure of eukaryotic cells based on electron micrographs.

SE: 14, 15-16

S.3 Interpretations of electron micrographs to identify organelles and deduce the function of specialized cells.

SE: 17-22

1.3 Membrane Structure Essential Idea: The structure of biological membranes makes them fluid and dynamic. U.1 Phospholipids form bilayers in water

due to the amphipathic properties of phospholipid molecules.

SE: 28-30

U.2 Membrane proteins are diverse in terms of structure, position in the membranes and function.

SE: 30-31

U.3 Cholesterol is a component of animal cell membranes.

SE: 28, 30





A.1 Cholesterol in mammalian membranes reduces membrane fluidity and permeability to some solutes.

SE: 30, 68-69

S.1 Drawing of the fluid mosaic model. SE: 28

S.2 Analysis of evidence from electron microscopy that led to the proposal of the Davidson-Danielli model.

SE: 28

S.3 Analysis of the falsification of the Davison-Danielli model that led to the Singer-Nicolson model.

SE: 28

1.4 Membrane Transport Essential Idea: Membranes control the composition of cells by active and passive

transport. U.1 Particles move across membranes

by simple diffusion, facilitated diffusion, osmosis and active transport.

SE: 31-38

U.2 The fluidity of membranes allows materials to be taken into cells by endocytosis or released by exocytosis. Vesicles move materials within cells.

SE: 37-38

A.1 Structure and function of the sodium-potassium pumps for active transport and potassium channels for facilitated diffusion in axons.

SE: 35-37

A.2 Tissues or organs to be used in medical procedures must be bathed in a solution with the same osmolarity as the cytoplasm to prevent osmosis.

SE: 32-33, 34 (Utilization)

S.1 Estimation of osmolarity in tissues by bathing samples in hypotonic and hypertonic solutions. (Practical 2)






1.5 Origin of Cells Essential Idea: There is an unbroken chain of life from the first cells on Earth to all cells

in organisms alive today. U.1 Cells can only be formed by division

of pre-existing cells. SE: 39

U.2 The first cells must have arisen from non-living material.

SE: 39

U.3 The origin of eukaryotic cells can be explained by the endosymbiotic theory.

SE: 40-41

A.1 Evidence from Pastuer’s experiments that spontaneous generation of cells and organisms does not now occur on Earth.

SE: 39-40

1.6 Cell Division Essential Idea: Cell division is essential but must be controlled. U.1 Mitosis is division of the nucleus into

two genetically identical daughter nuclei.

SE: 42, 44

U.2 Chromosomes condense by supercoiling during mitosis.

SE: 44-45

U.3 Cytokinesis occurs after mitosis and is different in plants and animal cells.

SE: 47-48

U.4 Interphase is a very active phase of the cell cycle with many processes occurring in the nucleus and cytoplasm.

SE: 43-44

U.5 Cyclins are involved in the control of the cell cycle.

SE: 43

U.6 Mutagens, oncogenes and metastasis are involved in the development of primary and secondary tumors.

SE: 49

A.1 The correlation between smoking and incidence of cancers.

SE: 49, 50 (Figure 1.35)

S.1 Identification of phases of mitosis in cells viewed with a microscope or in a micrograph.

SE: 47, 48

S.2 Determination of a mitotic index from a micrograph.

SE: 49 (Utilization), 50





Topic 2: Molecular Biology 2.1 Molecules to Metabolism Essential Idea: Living Organisms control their composition by complex web of chemical

reactions. U.1 Molecular biology explains living

processes in terms of the chemical substances involved

SE: 54, 55 (#1)

U.2 Carbon atoms can form four covalent bonds allowing a diversity of stable compounds to exist

SE: 55

U.3 Life is based on carbon compounds including carbohydrates, lipids proteins and nucleic acids

SE: 55-56

U.4 Metabolism is the web of all the enzyme-catalyzed reactions in a cell or organism

SE: 56-58

U.5 Anabolism is the synthesis of complex molecules from simpler molecules including the formation of macromolecules from monomers by condensation reactions

SE: 58-60

U.6 Catabolism is the breakdown of complex molecules into simpler molecules including the hydrolysis of macromolecules into monomers

SE: 58, 60

A.1 Urea as an example of a compound that is produced by living organisms but can also be artificially synthesized

SE: 60 (Nature of Science)

S.1 Drawing molecular diagrams of glucose, ribose, a saturated fatty acid and a generalized amino acid

SE: 61-62 (#2)

S.2 Identification of biochemical such as sugars, lipids, or amino acids from molecular drawings

SE: 61-62 (#2)

2.2 Water Essential Idea: Water is the medium of life. U.1 Water molecules are polar and

hydrogen bonds form between them. SE: 63-64

U.2 Hydrogen bonding and dipolarity explain the cohesive, adhesive, thermal and solvent properties of water.

SE: 64-66





U.3 Substances can be hydrophilic or hydrophobic.

SE: 66-67, 69

A.1 Comparison of the thermal properties of water with those of methane.

SE: 67 (Nature of Science; Figure 2.12)

A.2 Use of water as a coolant in sweat. SE: 65

A.3 Modes of transport of glucose, amino acids, cholesterol, fats. Oxygen, and sodium in blood in relations to their solubility in water.

SE: 68 (Table 2.4), 69 (Interesting Fact)

2.3 Carbohydrates and Lipids Essential Idea: Compounds of carbon, hydrogen and oxygen are used to supply and

store energy. U.1 Monosaccharide monomers are

linked together by condensation reactions to form disaccharides and polysaccharide polymers.

SE: 69-71

U.2 Fatty acids can be saturated, monounsaturated and polyunsaturated.

SE: 72

U.3 Unsaturated fatty acids can be cis or trans isomers.

SE: 73

U.4 Triglycerides are formed by condensation from three fatty acids and one glycerol.

SE: 73, 74 (Figure 2.19)

A.1 Structure and function of cellulose and starch in plants and glycogen in humans.

SE: 71, 71 (Table 2.5)

A.2 Scientific evidence for health risks of trans fat and saturated fatty acids.

SE: 72-73

A.3 Lipids are more suitable for long term energy storage in humans than carbohydrates.

SE: 74

A.4 Evaluation of evidence and the methods used to obtain the evidence for health claims made about lipids.


S.1 Use of molecular visualization software to compare cellulose, starch and glycogen.

SE: 76 (Hotlinks Site)

S.2 Determination of body mass index by calculation or use of a nomogram.

SE: 75, 76 (#3-6)





2.4 Proteins Essential Idea: Proteins have a very wide range of functions in living organisms. U.1 Amino Acids are linked together by

condensation to form polypeptides. SE: 77-78, 78 (Figure 2.21)

U.2 There are 20 different amino acids in polypeptides synthesized on ribosomes.

SE: 77-79

U.3 Amino Acids can be linked together in any sequence giving a huge range of possible polypeptides.

SE: 77-79

U.4 The amino acid sequence of polypeptides is coded for by genes.

SE: 78, 79

U.5 A protein may consist of a single polypeptide or more than one polypeptide linked together.

SE: 79-81, 80 (Figures 2.22, 2.24)

U.6 The amino acid sequence determines the three-dimensional conformation of a protein.

SE: 79

U.7 Living organisms synthesize many different proteins with a wide range of functions.

SE: 79 (Table 2.8), 80-81

U.8 Every individual has a unique proteome.

SE: 81

A.1 Rubisco, insulin immunoglobulins, rhodopsin, collagen and spider silk as examples of the range of protein functions.

SE: 79 (Table 2.8)

A.2 Denaturation of proteins by heat or by deviation of pH from the optimum.

SE: 81-82

S.1 Drawing molecular diagrams to show the formation of a peptide bond.

SE: 79 (#7)

2.5 Enzymes Essential Idea: Enzymes control the metabolism of the cell. U.1 Enzymes have an active site to

which specific substrates bind. SE: 83-84

U.2 Enzyme catalysis involves molecular motion and the collision of substrates with the active site.

SE: 83-84

U.3 Temperature, pH and substrate concentration affect the rate of activity of enzymes.

SE: 84-85





U.4 Enzymes are denatured. SE: 84-85

U.5 Immobilized enzymes are widely used in industry.

SE: 85-86

A.1 Methods of production of lactose-free milk and its advantages.

SE: 85

S.1 Design of experiments to test the effect of temperature, pH, and substrate concentration on the activity of enzymes.


S.2 Experimental investigation of a factor affecting enzyme activity. (Practical 3)


2.6 Structure of DNA and RNA Essential Idea: The structure of DNA allows efficient storage of genetic information. U.1 The nucleic acids DNA and RNA are

polymers of nucleotides. SE: 88-89

U.2 DNA differs from RNA in the number of strands present, the base composition and the type of pentose.

SE: 89, 91 (#10)

U.3 DNA is double helix made of two antiparallel strands of nucleotides linked by hydrogen bonding between complimentary base pairs.

SE: 89-91

A.1 Crick and Watson’s elucidation of the structure of DNA using model making.

SE: 90-91, 91 (Nature of Science)

S.1 Drawing simple diagrams of the structure of single nucleotides of DNA and RNA, using circles, pentagons, and rectangles to represent phosphates, pentoses and bases.

SE: 89 (Figure 2.31; #8), 90 (Figure 2.32)

2.7 DNA Replications, Transcription and Translation Essential Idea: Genetic information in DNA can be accurately copied and can be

translated to make the proteins needed by the cell. U.1 The replication of DNA is semi-

conservative and depends on complimentary base pairing.

SE: 93-94, 96 (Figure 2.39)

U.2 Helicase unwinds the double helix and separates the two strands by breaking hydrogen bonds.

SE: 92-94, 96





U.3 DNA polymerase links nucleotides together to form a new strand, using a pre-existing strand as a template.

SE: 93-94

U.4 Transcription is the synthesis of mRNA copied from the DNA base sequences by RNA polymerase.

SE: 97-98

U.5 Translation is the synthesis of polypeptides on ribosomes.

SE: 98-99

U.6 The amino acid sequence of polypeptides is determined by mRNA according to the genetic code.

SE: 98

U.7 Codons of three bases on mRNA correspond to one amino acid in a polypeptide.

SE: 98

U.8 Translation depends on complimentary base-pairing between codons on mRNA and anticodons on tRNA.

SE: 98-100 (Figure 2.41)

A.1 Use of Taq DNA polymerase to produce multiple copies of DNA rapidly by the polymerase chain reaction (PCR).

SE: 100

A.2 Production of human insulin in bacteria as an example of the universality of the genetic code allowing gene transfer between species.

SE: 99 (Key Fact)

S.1 Use a table of the genetic code to deduce which codons corresponds to which amino acids.

SE: 100 (#12)

S.2 Analysis of Messelson and Stahl’s results to obtain support for the theory of semi-conservative replication of DNA.

SE: 95-96 (#11)

S.3 Use a table of mRNA codons and their corresponding amino acids to deduce the sequence of amino acids coded by a short mRNA strand of known base sequence.

SE: 100 (#12)

S.4 Deducing the DNA base sequence for the mRNA strand.

SE: 100 (#12)





2.8 Cell Respiration Essential Idea: Cell respiration supplies energy for the functions of life. U.1 Cell respiration is the controlled

release of energy from organic compounds to produce ATP.

SE: 101-102

U.2 ATP from cell respiration is immediately available as a source of energy in the cell.

SE: 101-102, 104

U.3 Anaerobic cell respiration gives a small yield of ATP from glucose.

SE: 102-103, 104 (Figure 2.45)

U.4 Aerobic cell respiration requires oxygen and gives a large yield of ATP from glucose.

SE: 104, 105 (Figure 2.46)

A.1 Use of anaerobic cell respiration in yeasts to produce ethanol and carbon dioxide in baking.

SE: 103

A.2 Lactate production in humans when anaerobic respiration is used to maximize the power of muscle contractions.

SE: 103

S.1 Analysis of results from experiments involving measurement of respiration rates in germinating seeds or invertebrates using a respirometer.

SE: 105-106 (Worked Example; Figure 2.47; Nature of Science)

2.9 Photosynthesis Essential Idea: Photosynthesis uses the energy in sunlight to produce the chemical

energy needed for life. U.1 Photosynthesis is the production of

carbon compounds in cells using light energy.

SE: 41, 107, 110-111

U.2 Visible light has a range of wavelengths with violet the shortest wavelength and red the longest.

SE: 109

U.3 Chlorophyll absorbs red and blue light most effectively and reflects green light more than other colours.

SE: 107, 109-110

U.4 Oxygen is produced in photosynthesis from the photolysis of water.

SE: 110-111 (Figure 2.5)

U.5 Energy is needed to produce carbohydrates and other carbon compounds from carbon dioxide.

SE: 111





U.6 Temperature, light intensity and carbon dioxide concentration are possible limiting factors on the rate photosynthesis.

SE: 112-113 (#13)

A.1 Changes to the Earth’s atmosphere, oceans and rock deposition due to photosynthesis.

SE: 191 (Interesting Fact), 202-204

S.1 Drawing an absorption spectrum for chlorophyll and an action spectrum for photosynthesis.

SE: 109-110

S.2 Design an absorption spectrum for chlorophyll and an action spectrum for photosynthesis.

SE: 109-110

S.3 Separation of photosynthetic pigments by chromatograph. (Practical 4)

SE: 108 (Laboratory)

Topic 3: Genetics 3.1 Genes Essential Idea: Every living organism inherits a blueprint for life from its parents. U.1 A gene is a heritable factor that

consists of a length of DNA and influences a specific characteristic.

SE: 120

U.2 A gene occupies a specific position on a chromosome.

SE: 121 (Figure 3.2)

U.3 The various specific forms of a gene are alleles.

SE: 121-122

U.4 Alleles differ from each other by one or only a few bases.

SE: 123-124

U.5 New alleles are formed by mutation. SE: 124-128

U.6 The genome is the whole of the genetic information of an organism.

SE: 128-130

U.7 The entire base sequence of human genes was sequenced in the Human Genome Project.

SE: 130-131 (International-Mindedness)

A.1 The causes of sickle cell anemia, including a base substitution mutation, a change to the base sequence of mRNA transcribed from it and a change to the sequence of a polypeptide in hemoglobin.

SE: 126 (Table 3.3), 127-128 (Figure #3.7)

A.2 Comparison of the number of genes in humans with other species.

SE: 122 (Table 3.1; #2)





S.1 Use of a database to determine differences in the base sequence of a gene in two species.

SE: 123-124 (Worked Example), 132 (#3)

3.2 Chromosomes Essential Idea: Chromosomes carry genes in a linear sequence that is shared by

members of a species. U.1 Prokaryotes have one chromosome

consisting of a circular DNA molecule.

SE: 135 (Figure 3.10), 136 (Table 3.5), 140-141 (Figure 3.15)

U.2 Some prokaryotes also have plasmids but eukaryotes do not.

SE: 135 (Figure 3.10)

U.3 Eukaryote chromosomes are linear DNA molecules associated with histone proteins.

SE: 135-136 (Table 3.5)

U.4 In a eukaryote species there are different chromosomes that carry different genes.

SE: 136-137

U.5 Homologous chromosomes carry the same sequence of genes but not necessarily the same alleles of those genes.

SE: 136-137

U.6 Diploid nuclei have pairs of homologous chromosomes.

SE: 137-138

U.7 Haploid nuclei have one chromosomes of each pair.

SE: 137-138

U.8 The number of chromosomes is a characteristic feature of member of a species.

SE: 138 (Table 3.6)

U.9 A karyogram shows the chromosomes of an organism in homologous pairs of decreasing length.

SE: 138-139

U.10 Sex is determined by sex chromosomes and autosomes are chromosomes that do not determine sex.

SE: 139-140

A.1 Cairns’ technique for measuring the length of DNA by autoradiography.

SE: 140-141

A.2 Comparison of genome size in T2 phage, Escherichia coli, Drosophila melanogaster, Homo sapiens, Paris japonica.

SE: 122 (Table 3.1), 141 (#5)





A.3 Comparison of diploid chromosome numbers of Homo sapiens, Pan troglodytes, Canis familiaris, Oryza sativa, Parascarsis equorum.

SE: 138 (Table 3.6)

A.4 Use karyograms to deduce sex and diagnose Down Syndrome in humans.

SE: 138 (#4)

S.1 Use of databases to identify the focus of a human gene and its polypeptide product.

SE: 141 (#5), 142 (Hotlinks)

3.3 Meiosis Essential Idea: Alleles segregate during meiosis allowing new combinations to be formed

by the fusion of gametes. U.1 One of diploid nucleus divides by

meiosis to produce four haploid nuclei.

SE: 143 (Figure 3.16)

U.2 The halving of the chromosomes number allows a sexual life cycle with fusion of gametes.

SE: 142-143

U.3 DNA is replicated before meiosis so that all chromosomes consist of two sister chromatids.

SE: 143

U.4 The early stages of meiosis involved pairing of homologous chromosomes and crossing over followed condensation.

SE: 144

U.5 Orientation of pairs of homologous chromosomes prior to separation is random.

SE: 144

U.6 Separation of pairs of homologous chromosomes in the first division of meiosis halves the chromosome number.

SE: 145

U.7 Crossing over and random orientation promotes genetic variation.

SE: 144-146 (Figure 3.22)

U.8 Fusion of gametes from different parents promotes genetic variation.

SE: 146 (Figure 3.22)

A.1 Non-disjunction can cause Down syndrome and other chromosome abnormalities.

SE: 138, 147

A.2 Studies showing age of parents influences chances of non-disjunction.






A.3 Description of methods used to obtain cells for karyotype analysis e.g. chorionic villus sampling and amniocentesis and the associated risks.

SE: 138, 148

S.1 Drawing diagrams to show the stages of meiosis resulting in the formation of four haploid cells.

SE: 148 (#10)

3.4 Inheritance Essential Idea: The inheritance of genes follows patterns. U.1 Mendel discovered the principles of

inheritance with experiments in which large numbers of pea plants were crossed.

SE: 150 (Nature of Science), 151 (TOK)

U.2 Gametes are haploid so contain only one allele of each gene.

SE: 152

U.3 The alleles of each gene separate into different haploid daughter nuclei during meiosis.

SE: 152-154

U.4 Fusion of gametes results in diploid zygotes with two alleles of each gene that may be the same allele or different alleles.

SE: 152-154

U.5 Dominant alleles mask the effect of recessive alleles but co-dominant alleles have joint effects.

SE: 154-156

U.6 Many genetic diseases in human are due to excessive alleles of autosomal genes, although some genetic diseases are due to dominant or co-dominant alleles.

SE: 158-159, 161-162 (Worked Example #2)

U.7 Some genetic diseases are sex-linked. The pattern of inheritance is different with sex-linked genes due to their location on sex chromosomes.

SE: 159-160

U.8 Many genetic diseases have been identified in humans but most are very rare.

SE: 158-160

U.9 Radiation and mutagenic chemicals increase the mutation rate and can cause genetic diseases and cancer.

SE: 163 (Nature of Science), 164-165

A.1 Inheritance of ABO blood groups. SE: 157 (Worked Example)





A.2 Re-green color blindness and hemophilia as examples of sex-linked inheritance.

SE: 159-160

A.3 Inheritance of cystic fibrosis and Huntington’s disease.

SE: 158 (Figure 3.37), 161 (Worked Example)

A.4 Consequences of radiation after nuclear bombing of Hiroshima and accident at Chernobyl.

SE: 164-165

S.1 Construction of Punnett grids for predicting the outcomes of monohybrid genetic crosses.

SE: 152-156

S.2 Comparison of predicted and actual outcomes of genetic crosses using real data.

SE: 155

S.3 Analysis of pedigree charts to deduce the pattern of inheritance of genetic diseases.

SE: 157 (Worked Example), 158 (Figure 3.37), 161-162 (Worked Example)

3.5 Genetic Modification and Biotechnology Essential Idea: Biologists have developed techniques for artificial manipulation of DNA,

cells and organisms. U.1 Gel electrophoresis is used to

separate proteins or fragments of DNA according to size.

SE: 167 (Figure 3.42)

U.2 PCR can be used to amplify small amounts of DNA.

SE: 168

U.3 DNA profiling involves comparison of DNA.

SE: 168-170

U.4 Genetic modification is carried out by gene transfer between species.

SE: 170, 171 (Nature of Science; TOK)

U.5 Clones are groups of genetically identical organisms, derived from a single original parent cell.

SE: 171-172 (Figure 3.46)

U.6 Many plants species and some animal species have natural methods of cloning.

SE: 174-175

U.7 Animals can be cloned at the embryo stage by breaking up the embryo into more than one group of cells.

SE: 175

U.8 Methods have been developed for cloning adult animals using differentiated cells.

SE: 176 (Figure 3.49)





A.1 Use of DNA profiling in paternity and forensic investigations.

SE: 169 (#12)

A.2 Gene transfer in bacteria using plasmids makes use of restriction endonucleases and DNA ligases.

SE: 171-172

A.3 Assessment of potential risks and benefits associated with genetic modification of crops.

SE: 172-174

A.4 Production of clones embryos produced by somatic-cell nuclear transfer.

SE: 175

S.1 Design of an experiment to assess one factor affecting the rooting of stem-cuttings.

SE: 175 (Laboratory)

S.2 Analysis of examples of DNA profiles.

SE: 169 (#12)

S.3 Analysis of data on risks to monarch butterflies of Bt crops.

SE: 170, 171 (Nature of Science)

Topic 4: Ecology 4.1 Species, Communities and Ecosystems Essential Idea: The continued survival of living organisms including humans depends on

sustainable communities. U.1 Species are groups of organisms

that can potentially interbreed to produce fertile offspring.

SE: 183-184

U.2 Members of a species may be reproductively isolated in separate populations.

SE: 184-185

U.3 Species have either an autotrophic or heterotrophic method of nutrition (a few species have both methods).

SE: 185

U.4 Consumers are heterotrophs that feed on living organisms by ingestion.

SE: 185-186

U.5 Detrivores are heterotrophs that obtain organic nutrients from detritus by internal digestion.

SE: 186

U.6 Saprotrophs are heterotrophs that obtain organic nutrients from dead organisms by external digestion.

SE: 186-187





U.7 A community is formed by populations of different species living together and interacting with each other.

SE: 187

U.8 A community forms an ecosystem by its interactions with the abiotic environment.

SE: 188

U.9 Autotrophs obtain inorganic nutrients from the abiotic environment.

SE: 188 (Nature of Science), 191

U.10 The supply of inorganic nutrients is maintained by nutrient recycling.

SE: 191-192

U.11 Ecosystems have the potential to be sustainable over long periods of time.

SE: 192-194

S.1 Classifying species as autotrophs, consumers, detrivores or saprotrophs from a knowledge of their mode of nutrition.

SE: 185-187, 186 (#1), 187 (Table 4.1)

S.2 Setting up sealed mecocosms to try to establish sustainability. (Practical 5)


S.3 Testing for association between two species using the chi-squared test with data obtained from quadrat sampling.

SE: 188 (Laboratory), 189-191 (Worked Example)

S.4 Recognizing and interpreting statistical significance.

SE: 188 (Laboratory), 189-191 (Worked Example)

4.2 Energy Flow Essential Idea: Ecosystems require a continuous supply of energy to fuel life processes

and to replace energy lost as heat. U.1 Most ecosystems rely on a supply of

energy from sunlight. SE: 195

U.2 Light energy is converted to chemical energy in carbon compounds by photosynthesis.

SE: 196

U.3 Chemical energy in carbon compounds flows through food chains by means of feeding.

SE: 196-197

U.4 Energy released from carbon compounds by respiration is used in living organisms and converted to heat.

SE: 197





U.5 Living organisms cannot convert heat to other forms of energy.

SE: 197-198

U.6 Heat is lost from ecosystems. SE: 197-199

U.7 Energy losses between trophic levels restrict the length of food chains and the biomass of higher trophic levels.

SE: 199-200 (Nature of Science)

S.1 Quantitative representations of energy flow using pyramids of energy.

SE: 199 (Figure 4.5), 200 (Worked Example)

4.3 Carbon Cycling Essential Idea: Continued availability of carbon in ecosystems depends on carbon

cycling. U.1 Autotrophs convert carbon dioxide

into carbohydrates and other carbon compounds.

SE: 202-204

U.2 In aquatic ecosystems carbon is present as dissolved carbon dioxide and hydrogen carbonate ions.

SE: 204

U.3 Carbon dioxide diffuses from the atmosphere or water into autotrophs.

SE: 204

U.4 Carbon dioxide is produced by respiration and diffuses out of organisms into water or the atmosphere.

SE: 204

U.5 Methane is produced from organic matter in anaerobic conditions by methanogenic archaeans and some diffuses into the atmosphere or accumulates in the ground.

SE: 204-205

U.6 Methane is oxidized to carbon dioxide and water in the atmosphere.

SE: 205

U.7 Peat forms when organic matter is not fully decomposed because of acidic and/or anaerobic conditions in waterlogged soils.

SE: 205-206

U.8 Partially decomposed organic matter from past geological eras was converted either into coal or into oil and gases that accumulate in porous rocks.

SE: 206-209





U.9 Carbon dioxide is produced by combustion of biomass and fossilized organic matter.

SE: 209-210

U.10 Animals such as reef-building corals and Mollusca have hard parts that are composed of calcium carbonate and can become fossilized in limestone.

SE: 210-211

A.1 Estimation of carbon fluxes due to processes in the carbon cycle.

SE: 212 (#4)

A.2 Analysis of data from air monitoring stations to explain annual fluctuations.

SE: 212-213 (Worked Example), 214 (#7)

S.1 Construct a diagram of the carbon cycle.


4.4 Climate Change Essential Idea: Concentrations of gases in the atmosphere affect climates experienced

at the Earth’s surface. U.1 Carbon dioxide and water vapor are

the most significant greenhouse gases.

SE: 215-216

U.2 Other gases including methane and nitrogen oxides have less impact.

SE: 216, 217 (Table 4.7)

U.3 The impact of a gas depends on its ability to absorb long wave radiation as well as on its concentration in the atmosphere.

SE: 217

U.4 The warmed Earth emits longer wavelength radiation (heat).

SE: 217-218

U.5 Longer wave radiation is absorbed by greenhouse gases that retain the heat in the atmosphere.

SE: 215-218

U.6 Global temperatures and climate patterns are influenced by concentrations of greenhouse gases.

SE: 218-220

U.7 There is a correlation between rising atmospheric concentrations of carbon dioxide since the start of the industrial revolution 200 years ago and average global temperatures.

SE: 220

U.8 Recent increases in atmospheric carbon dioxide are largely due to increases in the combustion of fossilized organic matter.

SE: 220-222





A.1 Threats to coral reefs from increasing concentrations of dissolved carbon dioxide.

SE: 223

A.2 Correlations between global temperatures and carbon dioxide concentrations on Earth.

SE: 218-220, 219 (#5)

A.3 Evaluating claims that human activities are not causing climate change.

SE: 223-224 (Table 4.9)

Topic 5: Evolution and Biodiversity 5.1 Evidence for Evolution Essential Idea: There is overwhelming evidence for the evolution of life on Earth. U.1 Evolution occurs when heritable

characteristics of species change. SE: 229-230

U.2 The fossil record provides evidence for evolution.

SE: 230-233

U.3 Selective breeding of domesticated animals shows that artificial selection can cause evolution.

SE: 233

U.4 Evolution of homologous structures by adaptive radiation explains similarities in structure when there are differences in function.

SE: 234, 234 (#1)

U.5 Populations of a species can gradually diverge into separate species by evolution.

SE: 235-236 (Figure 5.6)

U.6 Continuous variation across the geographical range of related populations matches the concept of gradual divergence.

SE: 236-239, 240 (TOK)

A.1 Development of melanistic insects in polluted areas.

SE: 239 (Worked Example)

A.2 Comparison of the pentadactyl limb of mammals, birds, amphibians, and reptiles with different methods of locomotion.

SE: 234 (#1)

5.2 Natural Selection Essential Idea: The diversity of life has evolved and continues to evolve by natural

selection. U.1 Natural selection can only occur if

there is variation among members of the same species.

SE: 241-242





U.2 Mutation, meiosis and sexual reproduction cause variation between individuals in a species.

SE: 242-244

U.3 Adaptations are characteristics that make an individual suited to its environment and way of life.

SE: 244-245 (Figure 5.10)

U.4 Species tend to produce more offspring than the environment can support.

SE: 245

U.5 Individuals that are better adapted tend to survive and produce more offspring while the less well adapted tend to die or produce fewer offspring.

SE: 246-247

U.6 Individuals that reproduce pass on characteristics to their offspring.

SE: 247

U.7 Natural selection increases the frequency of characteristics that make individuals better adapted and decreases the frequency of other characteristics leading to changes within the species.

SE: 247-249

A.1 Changes in beaks of finches on Daphne Major.

SE: 245 (#2), 252 (Laboratory)

A.2 Evolution of antibiotic resistance in bacteria.


5.3 Classification and Biodiversity Essential Idea: Species are named and classified using an internationally agreed system. U.1 The binomial system of names for

species is universal among biologists and has been agreed and developed at a series of congresses.

SE: 253-255

U.2 When species are discovered they are given scientific names using the binomial system.

SE: 255-256

U.3 Taxonomists classify species using a hierarchy of taxa.

SE: 257

U.4 All organisms are classified into three domains.

SE: 257-258

U.5 The principal taxa for classifying eukaryotes are kingdom, phylum, class, order, family and genus and species.

SE: 258-259





U.6 In a natural classification, the genus and accompanying higher taxa consist of all the species that have evolved from one common ancestral species.

SE: 259-260

U.7 Taxonomists sometimes reclassify groups of species when new evidence shows that a previous taxon contains species that have evolved from different ancestral species.

SE: 260-262

U.8 Natural classification helps in identification of species and allows the prediction of characteristics shared by species within a group.

SE: 262-268

A.1 Classification of one plant and one animal species from domain to species level.

SE: 259 (Table 5.2)

A.2 Recognition features of bryophyte, filicinophyta, coniferophyta, and angiospermophyta.

SE: 263-264

A.3 Recognition features of porifera, cnidarian pletyhelmintha, annelida, Mollusca, arthropda and chordata.

SE: 264-266

A.4 Recognition of features of birds, mammals, amphibians, reptiles and fish.

SE: 266-268

S.1 Construction of dichotomous keys for use in identifying specimens

SE: 269 (#4)

5.4 Cladistics Essential Idea: The ancestry of groups of species can be deduced by comparing their

base or amino acid sequences. U.1 A clade is a group of organisms that

have evolved from a common ancestor.

SE: 271

U.2 Evidence for which species are part of a clade can be obtained from the base sequences of a gene or the corresponding amino acid sequence of a protein.

SE: 271-273, 281 (#15)





U.3 Sequence differences accumulate gradually so there is a positive correlation between the number of differences between two species and the time since they diverged from a common ancestor.

SE: 273-274

U.4 Traits can be analogous or homologous.

SE: 274-275, 275 (Table 5.6), 281 (#14)

U.5 Cladograms are tree diagrams that show the most probable sequence of divergence in clades.

SE: 275-276

U.6 Evidence from cladistics has shown that classifications of some groups based on structure did not correspond with the evolutionary origins of a group or species.

SE: 277

A.1 Cladograms including human and other primates.


A.2 Reclassification of the figwort family using evidence from cladistics.

SE: 278-279

S.1 Analysis of cladograms to deduce evolutionary relationships.

SE: 279-280 (Worked Example)

Topic 6: Human Physiology 6.1 Digestion and Absorption Essential Idea: The structure of the wall of the small intestine allows it to move, digest

and absorb food. U.1 The contraction of circular and

longitudinal muscle of the small intestine mixes the food with enzymes and moves it along the gut.

SE: 286-288

U.2 The pancreas secretes enzymes into the lumen of the small intestine.

SE: 288, 289 (Table 6.2)

U.3 Enzymes digest most macromolecules in food into monomers in the small intestine.

SE: 289

U.4 Villi increase the surface area of epithelium over which absorption is carried out.

SE: 289-290

U.5 Villi absorb monomers formed by digestion as well as mineral ions and vitamins.






U.6 Different methods of membrane transport are required to absorb different nutrients.


A.1 Processes occurring in the small intestine that results in the digestion of starch and transport of the products of digestion to the liver.

SE: 289-290

A.2 Use of dialysis tubing to model absorption of digested food in the intestine.


S.1 Production of an annotated diagram of the digestive system.


S.2 Identification of tissue layers in transverse sections of the small intestine viewed with a microscope or in a micrograph.


6.2 The Blood System Essential Idea: The blood system continuously transports substances to cells and

simultaneously collects waste products. U.1 Arteries convey blood at high

pressure from the ventricles to the tissues of the body.

SE: 292

U.2 Arteries have muscle cells and elastic fibres in their walls.

SE: 292, 293 (Table 6.3)

U.3 The muscle and elastic fibres assist in maintaining blood pressure between pump cycles.

SE: 292

U.4 Blood flows through tissues in capillaries. Capillaries have permeable walls that allow exchange of materials between cells in the tissue and the blood in the capillary.

SE: 292-293 (Table 6.3)

U.5 Veins collect blood at low pressure from the tissues of the body and return it to the atria of the heart.

SE: 293-294 (Table 6.3)

U.6 Valves in veins and the heart ensure circulation of blood by preventing backflow.

SE: 293

U.7 There is a separate circulation for the lungs.

SE: 292, 294 (Figure 6.6)

U.8 The heart beat is initiated by a group of specialized muscle cells in the right atrium called the sinoatrial node.

SE: 295





U.9 The sinoatrial node acts as a pacemaker.

SE: 295

U.10 The sinoatrial node sends out an electrical signal that stimulates contraction as it is propagated through the walls of the atria and then the walls of the ventricles.


U.11 The heart rate can be increased or decreased by impulses brought to the heart through two nerves from the medulla of the brain.

SE: 295-296

U.12 Epinephrine increases the heart rate to prepare for vigorous physical activity.

SE: 296

A.1 William Harvey’s discovery of the circulation of the blood with the heart acting as the pump.


A.2 Pressure changes in the left atrium, left ventricle and aorta during the cardiac cycle.

SE: 296-298, 296 (#2)

A.3 Causes and consequences of occlusion of the coronary arteries.

SE: 298

S.1 Identification of the blood vessels as arteries, capillaries or veins from the structure of their walls.

SE: 293 (Table 6.3)

S.2 Recognition of the chambers and valves of the heart and the blood vessels connected to it in dissected hearts or in diagrams of heart structure.

SE: 294 (Figure 6.6), 295 (#1)

6.3 Defense Against Infectious Disease Essential Idea: The human body has structures and processes that resist the continuous

threat of invasion by pathogens. U.1 The skin and mucous membranes

form a primary defense against pathogens that cause infectious disease.

SE: 300-301

U.2 Cuts in the skin are sealed by blood clotting.

SE: 302

U.3 Clotting factors are released from platelets.

SE: 302 (Figure 6.11)

U.4 The cascade results in the rapid conversion of fibrinogen to fibrin by thrombrin.

SE: 302 (Figure 6.11)





U.5 Ingestion of pathogens by phagocytic white blood cells gives non-specific immunity to diseases.

SE: 302-303

U.6 Production of antibodies by lymphocytes in response to particular pathogens gives specific immunity.

SE: 303-304

U.7 Antibiotic blocks processes that occur in prokaryotic cells but not in eukaryotic cells.

SE: 305-306

U.8 Viruses lack a metabolism and cannot therefore be treated with antibiotics.

SE: 306

U.9 Some strains of bacteria have evolved with genes that confer resistance to antibiotics and some strains of bacteria have multiple resistance.

SE: 306-307

A.1 Causes and consequences of blood clot formation in coronary arteries

SE: 298, 524

A.2 Florey and Chain’s experiments to test penicillin on bacterial infections in mice


A.3 Effects of HIV on the immune system and methods of transmission

SE: 304-306

6.4 Gas Exchange Essential Idea: The lungs are actively ventilated to ensure that gas exchange can occur

passively. U.1 Ventilation maintains concentration

gradients of oxygen and carbon dioxide between air and alveolu and blood flowing in adjacent capillaries.

SE: 308-312, 311 (Figure 6.14), 312 (Figure 6.15)

U.2 Type I pneumocytes are extremely thin alveolar cells that are adapted to carry out gas exchange.

SE: 312

U.3 Type II pneumocytes secrete a solution containing surfactant that creates a moist surface inside the alveoli to prevent the sides of the alveolus adhering to each other by reducing surface tension.

SE: 312

U.4 Air is carried to the lungs in the trachea and bronchi and then to the alveoli in bronchioles.

SE: 308-309 (Figure 6.12)





U.5 Muscle contraction causes the pressure changes inside the thorax that force air in and out of the lungs to ventilate them.

SE: 309-310 (Figure 6.13)

U.6 Different muscles are required for inspiration and expiration because muscles only do work when they contract.

SE: 309-310

A.1 Causes and consequences of lung cancer.

SE: 313

A.2 Causes and consequences of emphysema.

SE: 313

A.3 External and internal intercostal muscles, and diaphragm and abdominal muscles as examples of antagonistic muscle action.

SE: 310 (Key Fact)

S.1 Monitoring of ventilation in humans at rest and after mild and vigorous exercise. (Practical 6)


6.5 Neurons and Synapses Essential Idea: Neurons transmit the message, synapses modulate the message. U.1 Neurons transmit electrical impulses. SE: 315

U.2 The myelination of nerve fibres

allows for salutatory conduction. SE: 315-316 (Figure 6.16)

U.3 Neurons pump sodium and potassium ions across their membranes to generate a resting potential.

SE: 316-317 (Figure 6.17)

U.4 An action potential consists of depolarization and repolarization of the neuron.

SE: 316-317, 318 (Figure 6.18)

U.5 Nerve impulses are action potentials propagated along the axons f neurons.

SE: 316-318

U.6 Propagation of nerve impulses is the result of local currents that cause each successive part of the axon to reach the threshold potential.

SE: 319-320

U.7 Synapses are junctions between neurons and between neurons and receptors or effector cells.

SE: 320-321





U.8 When presynaptic neurons are depolarized they release a neurotransmitter into the synapse.

SE: 320-321 (Figure 6.21)

U.9 A nerve impulse is only initiated if the threshold potential is reached.

SE: 317 (Interesting Fact)

A.1 Secretion and reabsorption of acetylcholine by neurons at synapses.

SE: 321

A.2 Blocking of synaptic transmission at cholinergic synapses in insects by binding of neonicotinoid pesticides to acetylcholine receptors.

SE: 322

S.1 Analysis of oscilloscope traces showing resting potentials and action potentials.

SE: 320 (#5)

6.6 Hormones, Homeostasis and Reproduction Essential Idea: Hormones are used when signals need to be widely distributed. U.1 Insulin and glucagon are secreted by

beta and alpha cells of the pancreas respectively to control blood glucose concentrations.

SE: 326-327 (Figure 6.23)

U.2 Thyroxin is secreted by the thyroid gland to regulate the metabolic rate and help control body temperature.

SE: 325 (Interesting Fact)

U.3 Leptin is secreted by cells in adipose tissue and acts on the hypothalamus of the brain to inhibit appetite.

SE: 325

U.4 Melatonin is secreted by the pineal gland to control circadian rhythms.

SE: 325-326

U.5 A gene on the Y chromosomes causes embryonic gonads to develop as testes and secretes testosterone.

SE: 331

U.6 Testosterone causes pre-natal development of male genitalia and both sperm production and development of male secondary sexual characteristics during puberty.

SE: 328-329, 331-332

U.7 Estrogen and progesterone cause pre-natal development of female reproductive organs and female secondary sexual characteristics during puberty.

SE: 331-332





U.8 The menstrual cycle is controlled by negative and positive feedback mechanisms involving ovarian and pituitary hormones.

SE: 324, 332-334

A.1 Causes and treatment of Type I and Type II diabetes.

SE: 328

A.2 Testing of leptin on patients with clinical obesity and reasons for the failure to control the disease.

SE: 325

A.3 Causes of jet lag and use of melatonin to alleviate it.

SE: 325-326

A.4 The use of IVF of drugs to suspend the normal secretion of hormones, followed by the use of artificial doses of hormones to induce superovulation and establish a pregnancy.

SE: 334-335

A.5 William Harvey’s investigation of sexual reproduction in deer.


S.1 Annotate diagrams of the male and female reproductive system to show names of structures and their functions.

SE: 329-330

Option A: Neurobiology and behavior Essential idea: Modification of neurons starts in the earliest stages of embryogenesis

and continues to the final years of life. A.1 Neural development U.1 The neural tube of embryonic

chordates is formed by infolding of ectoderm followed by elongation of the tube.

SE: 340-343 (Interesting Fact)

U.2 Neurons are initially produced by differentiation in the neural tube.

SE: 343

U.3 Immature neurons migrate to a final location.

SE: 343

U.4 An axon grows from each immature neuron in response to chemical stimuli.

SE: 344 (Key Fact)

U.5 Some axons extend beyond the neural tube to reach other parts of the body.

SE: 344-345 (Figure 7.5; Key Fact)

U.6 A developing neuron forms multiple synapses.

SE: 345





U.7 Synapses that are not used do not persist.

SE: 345

U.8 Neural pruning involves the loss of unused neurons.


U.9 The plasticity of the nervous system allows it to change with experience.


A.1 Incomplete closure of the embryonic neural tube can cause spina bifida.

SE: 342 (Figure 7.3), 343

A.2 Events such as strokes may promote reorganization of brain function.

SE: 347-348

S.1 Annotation of a diagram of embryonic tissues in Xenopus, used as an animal model, during neurulation.

SE: 341 (#1)

G.1 Terminology relating to embryonic brain areas or nervous system divisions is not required.

SE: 340-341

Essential idea: The parts of the brain specialize in different functions. A.2 The human brain U.1 The anterior part of the neural tube

expands to form the brain. SE: 350

U.2 Different parts of the brain have specific roles.

SE: 350-352, 351 (Figure 7.7), 352 (Table 7.3)

U.3 The autonomic nervous system controls involuntary processes in the body using centres located mainly in the brain stem.

SE: 356-358, 359 (Figure 7.13)

U.4 The cerebral cortex forms a larger proportion of the brain and is more highly developed in humans than other animals.

SE: 360

U.5 The human cerebral cortex has become enlarged principally by an increase in total area with extensive folding to accommodate it within the cranium.

SE: 362-363

U.6 The cerebral hemispheres are responsible for higher order functions.

SE: 363-364 (Table 7.8)





U.7 The left cerebral hemisphere receives sensory input from sensory receptors in the right side of the body and the right side of the visual field in both eyes and vice versa for the right hemisphere.


U.8 The left cerebral hemisphere controls muscle contraction in the right side of the body and vice versa for the right hemisphere.

SE: 364-365

U.9 Brain metabolism requires large energy inputs.

SE: 365

A.1 Visual cortex, Broca’s area, nucleus accumbens as areas of the brain with specific functions.


A.2 Swallowing, breathing and heart rate as examples of activities coordinated by the medulla.

SE: 351-352, 352 (Figure 7.3)

A.3 Use of the pupil reflex to evaluate brain damage.

SE: 358-360

A.4 Use of animal experiments, autopsy, lesions and fMRI to identify the role of different brain parts.

SE: 352-356 (Table 7.4)

S.1 Identification of parts of the brain in a photograph, diagram or scan of the brain.

SE: 351 (Figure 7.7), 352, 353-354, 356 (Figure 7.4)

S.2 Analysis of correlations between body size and brain size in different animals.

SE: 361

G.1 Image of the brain should include the medulla oblongata, cerebellum, hypothalamus, pituitary gland and cerebral hemispheres.

SE: 351 (#2)

G.2 Although specific functions can be attributed to certain areas, brain imagery shows that some activities are spread in many areas and that the brain can even reorganize itself following a disturbance such as a stroke.

SE: 347-348





Essential idea: Living organisms are able to detect changes in the environment A.3 Perception of stimuli U.1 Receptors detect changes in the

environment. SE: 367, 368-369 (Table 7.9)

U.2 Rods and cones are photoreceptors located in the retina.

SE: 370 (Figure 7.23), 371

U.3 Rods and cones differ in their sensitivities to light intensities and wavelengths.

SE: 371-372 (Table 7.11)

U.4 Bipolar cells send the impulses from rods and cones to ganglion cells.

SE: 371

U.5 Ganglion cells send messages to the brain via the optic nerve.

SE: 370 (Figure 7.24), 371

U.6 The information from the right field of vision from both eyes is sent to the left part of the visual cortex and vice versa.

SE: 365 (Figure 7.20)

U.7 Structures in the middle ear transmit and amplify sound.

SE: 372-373 (Figure 7.26)

U.8 Sensory hairs of the cochlea detect sounds of specific wavelengths.

SE: 373-374 (Figure 7.27)

U.9 Impulses caused by sound perception are transmitted to the brain via the auditory nerve.

SE: 373-374

U.10 Hair cells in the semicircular canals detect movement of the head.

SE: 374

A.1 Red-green colour-blindness as a variant of normal trichromatic vision.

SE: 372

A.2 Detection of chemicals in the air by the many different olfactory receptors.

SE: 368-369 (Figure 7.21)

A.3 Use of cochlear implants in deaf patients.

SE: 374

S.1. Labelling a diagram of the structure of the human eye.

SE: 369 (Figure 7.22), 370 (#10)

S.2 Annotation of a diagram of the retina to show the cell types and the direction in which light moves.

SE: 370 (Figures 7.23, 7.24), 371 (#11)

S.3 Labelling a diagram of the structure of the human ear.

SE: 372 (Figure 7.25), 373 (#12)





G.1 Humans’ sensory receptors should include mechanoreceptors, chemoreceptors, thermoreceptors and photoreceptors.

SE: 368-369 (Table 7.9)

G.2 Diagram of human eye should include the sclera, cornea, conjunctiva, eyelid, choroid, aqueous humour, pupil, lens, iris, vitreous humour, retina, fovea, optic nerve and blind spot.

SE: 369 (Figure 7.22), 370 (#10)

G.3 Diagram of retina should include rod and cone cells, bipolar neurons and ganglion cells.

SE: 370 (Figures 7.23, 7.24), 371 (#11)

G.4 Diagram of ear should include pinna, eardrum, bones of the middle ear, oval window, round window, semicircular canals, auditory nerve and cochlea.

SE: 372 (Figure 7.25), 373 (#12)

Option B: Biotechnology and bioinformatics Essential idea: Microorganisms can be used and modified to perform industrial

processes. B.1 Microbiology: organisms in industry U.1 Microorganisms are metabolically

diverse. SE: 384-385 (Table 8.1)

U.2 Microorganisms are used in industry because they are small and have a fast growth rate.

SE: 384-385

U.3 Pathway engineering optimizes genetic and regulatory processes within microorganisms.

SE: 385-386

U.4 Pathway engineering is used industrially to produce metabolites of interest.

SE: 385-387

U.5 Fermenters allow large-scale production of metabolites by microorganisms.

SE: 388-391

U.6 Fermentation is carried out by batch or continuous culture.

SE: 388-391

U.7 Microorganisms in fermenters become limited by their own waste products.

SE: 391

U.8 Probes are used to monitor conditions within fermenters.

SE: 389-391





U.9 Conditions are maintained at optimal levels for the growth of the microorganisms being cultured.

SE: 390

A.1 Deep-tank batch fermentation in the mass production of penicillin.

SE: 389-390

A.2 Production of citric acid in a continuous fermenter by Aspergillus niger and its use as a preservative and flavouring.

SE: 391, 392 (#2-4)

A.3 Biogas is produced by bacteria and archaeans from organic matter in fermenters.

SE: 393-394

S.1 Gram staining of Gram-positive and Gram-negative bacteria.

SE: 394-395 (Figure 8.7)

S.2 Experiments showing zone of inhibition of bacterial growth by bactericides in sterile bacterial cultures.

SE: 306, 394-396

S.3 Production of biogas in a small-scale fermenter.

SE: 393-394

Essential idea: Crops can be modified to increase yields and to obtain novel products. B.2 Biotechnology in agriculture U.1 Transgenic organisms produce

proteins that were not previously part of their species’ proteome.

SE: 398

U.2 Genetic modification can be used to overcome environmental resistance to increase crop yields.

SE: 399

U.3 Genetically modified crop plants can be used to produce novel products.


U.4 Bioinformatics plays a role in identifying target genes.

SE: 407-409

U.5 The target gene is linked to other sequences that control its expression.

SE: 407-409

U.6 An open reading frame is a significant length of DNA from a start codon to a stop codon.

SE: 407-409

U.7 Marker genes are used to indicate successful uptake.

SE: 408-409





U.8 Recombinant DNA must be inserted into the plant cell and taken up by its chromosome or chloroplast DNA.

SE: 408-409

U.9 Recombinant DNA can be introduced into whole plants, leaf discs or protoplasts.

SE: 409

U.10 Recombinant DNA can be introduced by direct physical and chemical methods or indirectly by vectors.

SE: 404-407

A.1 Use of tumour-inducing (Ti) plasmid of Agrobacterium tumefaciens to introduce glyphosate resistance into soybean crops.

SE: 398-401, 407-409

A.2 Genetic modification of tobacco mosaic virus to allow bulk production of Hepatitis B vaccine in tobacco plants.

SE: 401

A.3 Production of Amflora potato (Solanum tuberosum) for paper and adhesive industries.

SE: 402

S.1 Evaluation of data on the environmental impact of glyphosate-tolerant soybeans.

SE: 402-403 (#5-13)

S.2 Identification of an open reading frame (ORF).


G.1 A significant length of DNA for an open reading frame contains sufficient nucleotides to code for a polypeptide chain.


G.2 Limit the chemical methods of introducing genes into plants to calcium chloride and liposomes.

SE: 405-406 (Figure 8.14; Table 8.4)

G.3 Limit the physical methods of introducing genes into plants to electroporation, microinjection and biolistics (gunshot).

SE: 404-405 (Table 8.3)

G.4 Limit vectors to Agrobacterium tumefaciens and tobacco mosaic virus.

SE: 406-407 (Figure 8.15; Table 8.5)





Essential idea: Biotechnology can be used in the prevention and mitigation of contamination from industrial, agricultural and municipal wastes.

B.3 Environmental protection U.1 Responses to pollution incidents can

involve bioremediation combined with physical and chemical procedures.

SE: 411

U.2 Microorganisms are used in bioremediation.

SE: 411-413 (Table 8.6)

U.3 Some pollutants are metabolized by microorganisms.

SE: 385-386, 411-413

U.4 Cooperative aggregates of microorganisms can form biofilms.

SE: 414

U.5 Biofilms possess emergent properties.

SE: 414-416, 417 (Figure 8.23)

U.6 Microorganisms growing in a biofilm are highly resistant to antimicrobial agents.

SE: 416, 417 (Figure 8.23)

U.7 Microorganisms in biofilms cooperate through quorum sensing.

SE: 417

U.8 Bacteriophages are used in the disinfection of water systems.

SE: 419

A.1 Degradation of benzene by halophilic bacteria such as Marinobacter.

SE: 412 (Figure 8.19)

A.2 Degradation of oil by Pseudomonas. SE: 412, 413 (Figure 8.20) A.3 Conversion by Pseudomonas of

methyl mercury into elemental mercury.

SE: 413

A.4 Use of biofilms in trickle filter beds for sewage treatment.

SE: 417 (Figure 8.24)

S.1 Evaluation of data or media reports on environmental problems caused by biofilms.

SE: 418 (#20-23)

G.1 Examples of environmental problems caused by biofilms could include clogging and corrosion of pipes, transfer of microorganisms in ballast water or contamination of surfaces in food production.

SE: 414-416





Option C: Ecology and conservation Essential idea: Community structure is an emergent property of an ecosystem. C.1 Species and communities U.1 The distribution of species is affected

by limiting factors. SE: 423-429

U.2 Community structure can be strongly affected by keystone species.


U.3 Each species plays a unique role within a community because of the unique combination of its spatial habitat and interactions with other species.

SE: 431-434

U.4 Interactions between species in a community can be classified according to their effect.

SE: 432-434

U.5 Two species cannot survive indefinitely in the same habitat if their niches are identical.


A.1 Distribution of one animal and one plant species to illustrate limits of tolerance and zones of stress.

SE: 429 (Table 9.1)

A.2 Local examples to illustrate the range of ways in which species can interact within a community.


A.3 The symbiotic relationship between Zooxanthellae and reef-building coral reef species.

SE: 434

S.1 Analysis of a data set that illustrates the distinction between fundamental and realized niche.

SE: 436, 437-438 (#5-8)

S.2 Use of a transect to correlate the distribution of plant or animal species with an abiotic variable.

SE: 438-439 (Figure 9.10; Utilization)

Essential idea: Changes in community structure affect and are affected by organisms. C.2 Communities and ecosystems U.1 Most species occupy different trophic

levels in multiple food chains. SE: 447-448 (Worked Example)

U.2 A food web shows all the possible food chains in a community.

SE: 447 (Figure 9.14), 448

U.3 The percentage of ingested energy converted to biomass is dependent on the respiration rate.

SE: 444, 446, 447 (Worked Example)





U.4 The type of stable ecosystem that will emerge in an area is predictable based on climate.

SE: 452

U.5 In closed ecosystems energy but not matter is exchanged with the surroundings.

SE: 460

U.6 Disturbance influences the structure and rate of change within ecosystems.

SE: 461 (Figure 9.25)

A.1 Conversion ratio in sustainable food production practices.

SE: 449-450

A.2 Consideration of one example of how humans interfere with nutrient cycling.

SE: 459-460

S.1 Comparison of pyramids of energy from different ecosystems.

SE: 448-449 (Table 9.5; Figure 9.15)

S.2 Analysis of a climograph showing the relationship between temperature, rainfall and the type of ecosystem.

SE: 457 (Figure 9.21; #16-19)

S.3 Construction of Gersmehl diagrams to show the inter-relationships between nutrient stores and flows between taiga, desert and tropical rainforest.

SE: 457, 458-459 (Worked Example; #20)

S.4 Analysis of data showing primary succession.

SE: 453 (Figure 9.17), 454 (#11-15)

S.5 Investigation into the effect of an environmental disturbance on an ecosystem.

SE: 450, 451 (Table 9.7)

G.1 Examples of aspects to investigate in the ecosystem could be species diversity, nutrient cycling, water movement, erosion, leaf area index, among others.

SE: 457-459

Essential idea: Human activities impact on ecosystem function. C.3 Impacts of humans on ecosystems U.1 Introduced alien species can escape

into local ecosystems and become invasive.

SE: 463, 464 (Key Fact), 465

U.2 Competitive exclusion and the absence of predators can lead to reduction in the numbers of endemic species when alien species become invasive.

SE: 464-465





U.3 Pollutants become concentrated in the tissues of organisms at higher trophic levels by biomagnification.

SE: 465-468

U.4 Macroplastic and microplastic debris has accumulated in marine environments.

SE: 468-470

A.1 Study of the introduction of cane toads in Australia and one other local example of the introduction of an alien species.

SE: 463-465

A.2 Discussion of the trade-off between control of the malarial parasite and DDT pollution.

SE: 467, 468 (Worked Example)

A.3 Case study of the impact of marine plastic debris on Laysan albatrosses and one other named species.

SE: 468

S.1 Analysis of data illustrating the causes and consequences of biomagnification.

SE: 472, 473-475 (#22-26)

S.2 Evaluation of eradication programmes and biological control as measures to reduce the impact of alien species.

SE: 470-472 (#21)

Essential idea: Entire communities need to be conserved in order to preserve biodiversity.

C.4 Conservation of biodiversity U.1 An indicator species is an organism

used to assess a specific environmental condition.

SE: 477-478

U.2 Relative numbers of indicator species can be used to calculate the value of a biotic index.

SE: 478 (Figure 9.33)

U.3 In situ conservation may require active management of nature reserves or national parks.

SE: 483-484

U.4 Ex situ conservation is the preservation of species outside their natural habitats.

SE: 485-486

U.5 Biogeographic factors affect species diversity.

SE: 486-487

U.6 Richness and evenness are components of biodiversity.

SE: 479





A.1 Case study of the captive breeding and reintroduction of an endangered animal species.

SE: 485-486

A.2 Analysis of the impact of biogeographic factors on diversity limited to island size and edge effects.

SE: 486-489 (#27-29; (Worked Example), 490 (#30-32)

S.1 Analysis of the biodiversity of two local communities using Simpson’s reciprocal index of diversity.


G.1 The formula for Simpson’s reciprocal index of diversity is:

N(N-1) D= --------- Σn(n-1) D = diversity index, N = total

number of organisms of all species found and n = number of individuals of a particular species.

SE: 479-480, 481 (Worked Example)

Option D: Human Physiology D.1 Human Nutrition Essential Idea: A balanced diet is essential to human health. U.1 Essential nutrients cannot be

synthesized by the body; therefore they have to be included in the diet.

SE: 496

U.2 Dietary minerals are essential chemical elements.

SE: 496

U.3 Vitamins are chemically diverse carbon compounds that cannot be synthesized by the body.


U.4 Some fatty acids and some amino acids are essential.

SE: 498-499

U.5 Lack of essential amino acids affects the production of proteins.

SE: 498-499, 500 (Figure 10.2)

U.6 Malnutrition may be caused by a deficiency, imbalance or excess of nutrients in the diet.

SE: 502-503

U.7 Appetite is controlled by a centre in the hypothalamus.

SE: 500-501

U.8 Overweight individuals are more likely to suffer hypertension and type II diabetes.

SE: 501-502





U.9 Starvation can lead to breakdown of body tissue.

SE: 501 (Key Fact)

A.1 Production of ascorbic acid by some mammals, but not others that need a dietary supply.

SE: 497

A.2 Cause and treatment of phenylketonuria (PKU).

SE: 499

A.3 Lack of Vitamin D or calcium can affect bone mineralization and cause rickets or osteomalacia.

SE: 496-497 (Utilization)

A.4 Breakdown of heart muscle due to anorexia.

SE: 501 (Key Fact)

A.5 Cholesterol in blood as an indicator of the risk of coronary heart disease.

SE: 488 (Key Fact)

S.1 Determination of the energy content of food by combustion.

SE: 74, 502

S.2 Use of databases of nutritional content of foods and software to calculate intakes of essential nutrients from a daily diet.

Supporting content: SE: Human Nutrition, 495-503

D.2 Digestion Essential Idea: Digestion is controlled by nervous and hormonal mechanisms. U.1 Nervous and hormonal mechanisms

control the secretion of digestive juices.

SE: 504-506

U.2 Exocrine glands secrete to the surface of the body or the lumen of the gut.

SE: 504, 505 (Table 10.1)

U.3 The volume and content of gastric secretions are controlled by nervous and hormonal mechanisms.

SE: 506

U.4 Acid conditions in the stomach favour some hydrolysis reactions and help to control pathogens in ingested food.

SE: 506-507

U.5 The structure of cells of the epithelium of the villi is adapted to the absorption of food.

SE: 508-509

U.6 The rate of transit of materials through the large intestine is positively correlated with their fibre content.

SE: 511





U.7 Materials not absorbed are egested. SE: 510 A.1 The reduction of stomach acid

secretion by proton pump inhibitor drugs.

SE: 506 (Utilization)

A.2 Dehydration due to cholera toxin. SE: 509 (International Mindedness) A.3 Helicobacter pylori infection as a

cause of stomach ulcers. SE: 507-508

S.1 Identification of exocrine gland cells that secrete digestive juices and villus epithelium cells that absorb digested foods from electron micrographs.

SE: 506 (Figure 10.4), 509 (Figure 10.5)

G.1 Adaptations of villus epithelial cells include microvilli and mitochondria.

SE: 508-509

D.3 Functions of the Liver Essential Idea: The chemical composition of the blood is regulated by the liver. U.1 The liver removes toxins from the

blood and detoxifies them. SE: 513-514

U.2 Components of red blood cells are recycled by the liver.

SE: 515

U.3 The breakdown of erythrocytes starts with phagocytosis of red blood cells by Kupffer cells.

SE: 513-515

U.4 Iron is carried to the bone marrow to produce hemoglobin in new red blood cells.

SE: 515

U.5 Surplus cholesterol is converted to bile salts.


U.6 Endoplasmic reticulum and Golgi apparatus in hepatocytes produce plasma proteins.

SE: 516-517

U.7 The liver intercepts blood from the gut to regulate nutrient levels.

SE: 514-515

U.8 Some nutrients in excess can be stored in the liver.

SE: 514-515 (Table 10.2)

A.1 Causes and consequences of jaundice.

SE: 517

A.2 Dual blood supply to the liver and differences between sinusoids and capillaries.

SE: 512-513





D.4 The Heart Essential Idea: Internal and external factors influence heart function. U.1 Structure of cardiac muscle cells

allows propagation of stimuli through the heart wall.

SE: 518-519

U.2 Signals from the sinoatrial node that cause contraction cannot pass directly from atria to ventricles.

SE: 521-522

U.3 There is a delay between the arrival and passing on of a stimulus at the atrioventricular node.

SE: 522 (Figure 10.12), 523

U.4 This delay allows time for atrial systole before the atrioventricular valves close.

SE: 522 (Figure 10.12), 523

U.5 Conducting fibres ensure coordinated contraction of the entire ventricle wall.

SE: 522

U.6 Normal heart sounds are caused by the atrioventricular valves and semilunar valves closing causing changes in blood flow.

SE: 521

A.1 Use of artificial pacemakers to regulate the heart rate.

SE: 523-524

A.2 Use of defibrillation to treat life-threatening cardiac conditions.

SE: 524

A.3 Causes and consequences of hypertension and thrombosis.

SE: 524-525

S.1 Measurement and interpretation of the heart rate under different conditions.

SE: 525, 526 (Table 10.4)

S.2 Interpretation of systolic and diastolic blood pressure measurements.

SE: 526 (Table 10.4)

S.3 Mapping of the cardiac cycle to a normal ECG trace.

SE: 519-520, 523 (Figure 10.14)

S.4 Analysis of epidemiological data relating to the incidence of coronary heart disease.


G.1 Include branching and intercalated discs in structure of cardiac muscle.

SE: 518-519

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