IB Diploma Biology SL specification checklist

All 328 spec points that our notes cover, topic by topic. Rate each one red, amber or green as you revise, and follow the link to the note when you need it.

IB Diploma Biology SL specification checklistclockitwithsci.com

How to use: tick one box for each spec point as you revise. Go back to the “Not yet” rows first, and keep going until every row is “Confident”.

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The numbers are IB's own spec references. Teachers: you are welcome to print this checklist and share it with your classes.

A1Molecules (Unity and diversity)

Water · A1.1

Spec	What to know (the note)	Not yet	Nearly	Confident
A1.1.1	Water as the medium for life and hydrogen bonding
A1.1.2	Water as the medium for life and hydrogen bonding
A1.1.3	Cohesion and adhesion
A1.1.4	Cohesion and adhesion
A1.1.5	Solvent properties of water
A1.1.6	Physical properties of water and aquatic animals

Nucleic acids · A1.2

Spec	What to know (the note)	Not yet	Nearly	Confident
A1.2.1	DNA as the genetic material and nucleotides
A1.2.2	DNA as the genetic material and nucleotides
A1.2.3	DNA as the genetic material and nucleotides
A1.2.4	DNA as the genetic material and nucleotides
A1.2.5	RNA polymers and the DNA double helix
A1.2.6	RNA polymers and the DNA double helix
A1.2.7	Differences between DNA and RNA
A1.2.8	Base pairing, information storage and the genetic code
A1.2.9	Base pairing, information storage and the genetic code
A1.2.10	Base pairing, information storage and the genetic code

A2Cells (Unity and diversity)

Cell structure · A2.2

Spec	What to know (the note)	Not yet	Nearly	Confident
A2.2.1	Cell theory and structures common to all cells
A2.2.2	Microscopy skills
A2.2.3	Developments in microscopy
A2.2.4	Cell theory and structures common to all cells
A2.2.5	Prokaryote and eukaryote cell structure
A2.2.6	Prokaryote and eukaryote cell structure
A2.2.7	Processes of life in unicellular organisms
A2.2.8	Animal, fungal and plant cells, and atypical cells
A2.2.9	Animal, fungal and plant cells, and atypical cells
A2.2.10	Micrographs, drawing and annotation
A2.2.11	Micrographs, drawing and annotation

A3Organisms (Unity and diversity)

Diversity of organisms · A3.1

Spec	What to know (the note)	Not yet	Nearly	Confident
A3.1.1	Variation, species and binomial names
A3.1.2	Variation, species and binomial names
A3.1.3	Variation, species and binomial names
A3.1.4	The biological species concept and speciation
A3.1.5	The biological species concept and speciation
A3.1.6	Chromosome numbers and karyograms
A3.1.7	Chromosome numbers and karyograms
A3.1.8	Unity and diversity of genomes
A3.1.9	Unity and diversity of genomes
A3.1.10	Unity and diversity of genomes
A3.1.11	Whole genome sequencing

A4Ecosystems (Unity and diversity)

Evolution and speciation · A4.1

Spec	What to know (the note)	Not yet	Nearly	Confident
A4.1.1	Evolution as change in heritable characteristics
A4.1.2	Evidence from sequences and selective breeding
A4.1.3	Evidence from sequences and selective breeding
A4.1.4	Homologous and analogous structures
A4.1.5	Homologous and analogous structures
A4.1.6	Speciation, reproductive isolation and differential selection
A4.1.7	Speciation, reproductive isolation and differential selection

Conservation of biodiversity · A4.2

Spec	What to know (the note)	Not yet	Nearly	Confident
A4.2.1	Biodiversity and the number of species
A4.2.2	Biodiversity and the number of species
A4.2.3	Anthropogenic species extinction and ecosystem loss
A4.2.4	Anthropogenic species extinction and ecosystem loss
A4.2.5	Evidence for and causes of the biodiversity crisis
A4.2.6	Evidence for and causes of the biodiversity crisis
A4.2.7	Approaches to conservation and the EDGE of Existence programme
A4.2.8	Approaches to conservation and the EDGE of Existence programme

B1Molecules (Form and function)

Carbohydrates and lipids · B1.1

Spec	What to know (the note)	Not yet	Nearly	Confident
B1.1.1	Carbon atoms and the diversity of carbon compounds
B1.1.2	Condensation and hydrolysis reactions
B1.1.3	Condensation and hydrolysis reactions
B1.1.4	Monosaccharides: form and function
B1.1.5	Starch, glycogen and cellulose
B1.1.6	Starch, glycogen and cellulose
B1.1.7	Glycoproteins and cell–cell recognition
B1.1.8	Lipids: hydrophobic properties, triglycerides and phospholipids
B1.1.9	Lipids: hydrophobic properties, triglycerides and phospholipids
B1.1.10	Fatty acids, energy storage and insulation
B1.1.11	Fatty acids, energy storage and insulation
B1.1.12	Phospholipid bilayers and steroids
B1.1.13	Phospholipid bilayers and steroids

Proteins · B1.2

Spec	What to know (the note)	Not yet	Nearly	Confident
B1.2.1	Amino acids and peptide bonds
B1.2.2	Amino acids and peptide bonds
B1.2.3	Dietary amino acids and the variety of peptide chains
B1.2.4	Dietary amino acids and the variety of peptide chains
B1.2.5	Effect of pH and temperature on protein structure

B2Cells (Form and function)

Membranes and membrane transport · B2.1

Spec	What to know (the note)	Not yet	Nearly	Confident
B2.1.1–B2.1.3	Lipid bilayers, barriers and simple diffusion
B2.1.4	Membrane proteins, glycoproteins and the fluid mosaic model
B2.1.5–B2.1.8	Osmosis, channel proteins and pump proteins
B2.1.9	Membrane proteins, glycoproteins and the fluid mosaic model
B2.1.10	Membrane proteins, glycoproteins and the fluid mosaic model

Organelles and compartmentalization · B2.2

Spec	What to know (the note)	Not yet	Nearly	Confident
B2.2.1–B2.2.3	Organelles, the nucleus and compartments

Cell specialization · B2.3

B3Organisms (Form and function)

Gas exchange · B3.1

Spec	What to know (the note)	Not yet	Nearly	Confident
B3.1.1	Gas exchange and exchange surfaces
B3.1.2	Gas exchange and exchange surfaces
B3.1.3	Gas exchange and exchange surfaces
B3.1.4	Adaptations of mammalian lungs
B3.1.5	Ventilation and lung volumes
B3.1.6	Ventilation and lung volumes
B3.1.7	Gas exchange in leaves
B3.1.8	Gas exchange in leaves
B3.1.9	Transpiration and stomatal density
B3.1.10	Transpiration and stomatal density

Transport · B3.2

Spec	What to know (the note)	Not yet	Nearly	Confident
B3.2.1	Adaptations of capillaries
B3.2.2	Structure and adaptations of arteries and veins
B3.2.3	Structure and adaptations of arteries and veins
B3.2.4	Pulse rates and occlusion of the coronary arteries
B3.2.5	Structure and adaptations of arteries and veins
B3.2.6	Pulse rates and occlusion of the coronary arteries
B3.2.7	Water transport in xylem
B3.2.8	Water transport in xylem
B3.2.9	Tissues in dicotyledonous stems and roots
B3.2.10	Tissues in dicotyledonous stems and roots

B4Ecosystems (Form and function)

Adaptation to environment · B4.1

Spec	What to know (the note)	Not yet	Nearly	Confident
B4.1.1	Habitats and adaptations to the abiotic environment
B4.1.2	Habitats and adaptations to the abiotic environment
B4.1.3	Abiotic variables and range of tolerance
B4.1.4	Abiotic variables and range of tolerance
B4.1.5	Conditions required for coral reef formation
B4.1.6	Terrestrial biomes
B4.1.7	Terrestrial biomes
B4.1.8	Adaptations to hot deserts and tropical rainforest

Ecological niches · B4.2

Spec	What to know (the note)	Not yet	Nearly	Confident
B4.2.1	Ecological niche and tolerance of oxygen
B4.2.2	Ecological niche and tolerance of oxygen
B4.2.3	Photosynthesis and mixotrophic nutrition
B4.2.4	Holozoic and saprotrophic nutrition, and archaea
B4.2.5	Photosynthesis and mixotrophic nutrition
B4.2.6	Holozoic and saprotrophic nutrition, and archaea
B4.2.7	Holozoic and saprotrophic nutrition, and archaea
B4.2.8	Dentition and diet in the Hominidae
B4.2.9	Adaptations for herbivory and predation
B4.2.10	Adaptations for herbivory and predation
B4.2.11	Adaptations of plant form for harvesting light
B4.2.12	Fundamental and realized niches, and competitive exclusion
B4.2.13	Fundamental and realized niches, and competitive exclusion

C1Molecules (Interaction and interdependence)

Enzymes and metabolism · C1.1

Spec	What to know (the note)	Not yet	Nearly	Confident
C1.1.1	Enzymes as catalysts and their role in metabolism
C1.1.2	Enzymes as catalysts and their role in metabolism
C1.1.3	Enzymes as catalysts and their role in metabolism
C1.1.4	Active sites, induced fit, collisions and denaturation
C1.1.5	Active sites, induced fit, collisions and denaturation
C1.1.6	Active sites, induced fit, collisions and denaturation
C1.1.7	Active sites, induced fit, collisions and denaturation
C1.1.8	Effects of temperature, pH and substrate concentration
C1.1.9	Effects of temperature, pH and substrate concentration
C1.1.10	Effect of enzymes on activation energy

Cell respiration · C1.2

Spec	What to know (the note)	Not yet	Nearly	Confident
C1.2.1	ATP: the molecule that distributes energy
C1.2.2	ATP: the molecule that distributes energy
C1.2.3	ATP: the molecule that distributes energy
C1.2.4	Cell respiration: aerobic and anaerobic
C1.2.5	Cell respiration: aerobic and anaerobic
C1.2.6	Variables affecting the rate of cell respiration

Photosynthesis · C1.3

Spec	What to know (the note)	Not yet	Nearly	Confident
C1.3.1	Photosynthesis: energy, carbon dioxide, water and oxygen
C1.3.2	Photosynthesis: energy, carbon dioxide, water and oxygen
C1.3.3	Photosynthesis: energy, carbon dioxide, water and oxygen
C1.3.4	Separating photosynthetic pigments by chromatography
C1.3.5	Absorption of light, absorption spectra and action spectra
C1.3.6	Absorption of light, absorption spectra and action spectra
C1.3.7	Investigating limiting factors on photosynthesis
C1.3.8	Carbon dioxide enrichment experiments

C2Cells (Interaction and interdependence)

Neural signalling · C2.2

Spec	What to know (the note)	Not yet	Nearly	Confident
C2.2.1	Neurons and the resting potential
C2.2.2	Neurons and the resting potential
C2.2.3	Nerve impulses as action potentials
C2.2.4	Speed of nerve impulses
C2.2.5	Synapses and excitatory postsynaptic potentials
C2.2.6	Synapses and excitatory postsynaptic potentials
C2.2.7	Synapses and excitatory postsynaptic potentials
C2.2.11	Speed of nerve impulses

C3Organisms (Interaction and interdependence)

Integration of body systems · C3.1

Spec	What to know (the note)	Not yet	Nearly	Confident
C3.1.1	System integration and the hierarchy of subsystems
C3.1.2	System integration and the hierarchy of subsystems
C3.1.3	System integration and the hierarchy of subsystems
C3.1.4	The brain, spinal cord, neurons and nerves
C3.1.5	The brain, spinal cord, neurons and nerves
C3.1.6	The brain, spinal cord, neurons and nerves
C3.1.7	The brain, spinal cord, neurons and nerves
C3.1.8	The brain, spinal cord, neurons and nerves
C3.1.9	Pain reflex arcs and the cerebellum
C3.1.10	Pain reflex arcs and the cerebellum
C3.1.11	Melatonin, epinephrine and control by the hypothalamus and pituitary
C3.1.12	Melatonin, epinephrine and control by the hypothalamus and pituitary
C3.1.13	Melatonin, epinephrine and control by the hypothalamus and pituitary
C3.1.14	Feedback control of heart rate and ventilation rate
C3.1.15	Feedback control of heart rate and ventilation rate
C3.1.16	Control of peristalsis by the CNS and enteric nervous system

Defence against disease · C3.2

Spec	What to know (the note)	Not yet	Nearly	Confident
C3.2.1	Pathogens as the cause of infectious diseases
C3.2.2	Skin, mucous membranes and blood clotting
C3.2.3	Skin, mucous membranes and blood clotting
C3.2.4	Innate and adaptive immunity, and phagocytes
C3.2.5	Innate and adaptive immunity, and phagocytes
C3.2.6	Lymphocytes, antigens and antibody production
C3.2.7	Lymphocytes, antigens and antibody production
C3.2.8	Lymphocytes, antigens and antibody production
C3.2.9	Lymphocytes, antigens and antibody production
C3.2.10	Immunity, vaccines and herd immunity
C3.2.11	HIV transmission and AIDS
C3.2.12	HIV transmission and AIDS
C3.2.13	Antibiotics and antibiotic resistance
C3.2.14	Antibiotics and antibiotic resistance
C3.2.15	Zoonoses and evaluating COVID-19 data
C3.2.16	Immunity, vaccines and herd immunity
C3.2.17	Immunity, vaccines and herd immunity
C3.2.18	Zoonoses and evaluating COVID-19 data

C4Ecosystems (Interaction and interdependence)

Populations and communities · C4.1

Spec	What to know (the note)	Not yet	Nearly	Confident
C4.1.1	Populations and random sampling
C4.1.2	Populations and random sampling
C4.1.3	Populations and random sampling
C4.1.4	Capture–mark–release–recapture and the Lincoln index
C4.1.5	Carrying capacity and density-dependent factors
C4.1.6	Carrying capacity and density-dependent factors
C4.1.7	Population growth curves
C4.1.8	Population growth curves
C4.1.9	Intraspecific and interspecific relationships
C4.1.10	Intraspecific and interspecific relationships
C4.1.11	Intraspecific and interspecific relationships
C4.1.12	Mutualism
C4.1.13	Invasive species and testing for competition
C4.1.14	Invasive species and testing for competition
C4.1.15	Invasive species and testing for competition
C4.1.16	Predator–prey relationships and control of populations
C4.1.17	Predator–prey relationships and control of populations
C4.1.18	Allelopathy and secretion of antibiotics

Transfers of energy and matter · C4.2

Spec	What to know (the note)	Not yet	Nearly	Confident
C4.2.1	Ecosystems as open systems and the source of energy
C4.2.2	Ecosystems as open systems and the source of energy
C4.2.3	Food chains, food webs and decomposers
C4.2.4	Food chains, food webs and decomposers
C4.2.5	Food chains, food webs and decomposers
C4.2.6	Autotrophs and heterotrophs
C4.2.7	Autotrophs and heterotrophs
C4.2.8	Autotrophs and heterotrophs
C4.2.9	Autotrophs and heterotrophs
C4.2.10	Trophic levels and energy pyramids
C4.2.11	Trophic levels and energy pyramids
C4.2.12	Energy losses between trophic levels
C4.2.13	Energy losses between trophic levels
C4.2.14	Energy losses between trophic levels
C4.2.15	Primary and secondary production
C4.2.16	Primary and secondary production
C4.2.17	The carbon cycle, carbon sinks and combustion
C4.2.18	The carbon cycle, carbon sinks and combustion
C4.2.19	The carbon cycle, carbon sinks and combustion
C4.2.20	The Keeling Curve
C4.2.21	Interdependence of autotrophs and heterotrophs and recycling of elements
C4.2.22	Interdependence of autotrophs and heterotrophs and recycling of elements

D1Molecules (Continuity and change)

DNA replication · D1.1

Spec	What to know (the note)	Not yet	Nearly	Confident
D1.1.1	Exact copies by semi-conservative replication
D1.1.2	Exact copies by semi-conservative replication
D1.1.3	Roles of helicase and DNA polymerase
D1.1.4	PCR and gel electrophoresis
D1.1.5	Applications of PCR and gel electrophoresis

Protein synthesis · D1.2

Spec	What to know (the note)	Not yet	Nearly	Confident
D1.2.1	Transcription and gene expression
D1.2.2	Transcription and gene expression
D1.2.3	Transcription and gene expression
D1.2.4	Transcription and gene expression
D1.2.5	Translation at the ribosome
D1.2.6	Translation at the ribosome
D1.2.7	Translation at the ribosome
D1.2.8	The genetic code
D1.2.9	The genetic code
D1.2.10	Translation at the ribosome
D1.2.11	Mutations that change protein structure

Mutation and gene editing · D1.3

Spec	What to know (the note)	Not yet	Nearly	Confident
D1.3.1	Substitutions, insertions and deletions
D1.3.2	Substitutions, insertions and deletions
D1.3.3	Substitutions, insertions and deletions
D1.3.4	Causes of mutation and randomness
D1.3.5	Causes of mutation and randomness
D1.3.6	Germ and somatic cells, and mutation as a source of variation
D1.3.7	Germ and somatic cells, and mutation as a source of variation

D2Cells (Continuity and change)

Cell and nuclear division · D2.1

Spec	What to know (the note)	Not yet	Nearly	Confident
D2.1.1	Cell division and cytokinesis
D2.1.2	Cell division and cytokinesis
D2.1.3	Cell division and cytokinesis
D2.1.4	Mitosis, meiosis and chromosome movement
D2.1.5	Mitosis, meiosis and chromosome movement
D2.1.6	Mitosis, meiosis and chromosome movement
D2.1.7	Phases of mitosis
D2.1.8	Phases of mitosis
D2.1.9	Meiosis, non-disjunction and variation
D2.1.10	Meiosis, non-disjunction and variation
D2.1.11	Meiosis, non-disjunction and variation

Water potential · D2.3

Spec	What to know (the note)	Not yet	Nearly	Confident
D2.3.1	Solvation and osmosis
D2.3.2	Solvation and osmosis
D2.3.3	Solvation and osmosis
D2.3.4	Osmosis in plant tissue: the practical
D2.3.5	Water movement in cells with and without walls
D2.3.6	Water movement in cells with and without walls
D2.3.7	Water movement in cells with and without walls

D3Organisms (Continuity and change)

Reproduction · D3.1

Spec	What to know (the note)	Not yet	Nearly	Confident
D3.1.1	Sexual and asexual reproduction
D3.1.2	Sexual and asexual reproduction
D3.1.3	Male and female sexes and human reproductive systems
D3.1.4	Male and female sexes and human reproductive systems
D3.1.5	Ovarian and uterine cycles and their hormones
D3.1.6	Fertilization in humans and hormones in IVF
D3.1.7	Fertilization in humans and hormones in IVF
D3.1.8	Sexual reproduction in flowering plants and insect-pollinated flowers
D3.1.9	Sexual reproduction in flowering plants and insect-pollinated flowers
D3.1.10	Cross-pollination and self-incompatibility
D3.1.11	Cross-pollination and self-incompatibility
D3.1.12	Seed dispersal and germination

Inheritance · D3.2

Spec	What to know (the note)	Not yet	Nearly	Confident
D3.2.1	Haploid gametes, diploid zygotes and genetic crosses in plants
D3.2.2	Haploid gametes, diploid zygotes and genetic crosses in plants
D3.2.3	Genotype, phenotype, dominance and phenotypic plasticity
D3.2.4	Genotype, phenotype, dominance and phenotypic plasticity
D3.2.5	Genotype, phenotype, dominance and phenotypic plasticity
D3.2.6	Genotype, phenotype, dominance and phenotypic plasticity
D3.2.7	Phenylketonuria, SNPs, multiple alleles and ABO blood groups
D3.2.8	Phenylketonuria, SNPs, multiple alleles and ABO blood groups
D3.2.9	Phenylketonuria, SNPs, multiple alleles and ABO blood groups
D3.2.10	Incomplete dominance and codominance
D3.2.11	Sex determination, sex linkage and haemophilia
D3.2.12	Sex determination, sex linkage and haemophilia
D3.2.13	Pedigree charts
D3.2.14	Continuous variation and box-and-whisker plots
D3.2.15	Continuous variation and box-and-whisker plots

Homeostasis · D3.3

Spec	What to know (the note)	Not yet	Nearly	Confident
D3.3.1	Homeostasis and negative feedback
D3.3.2	Homeostasis and negative feedback
D3.3.3	Regulation of blood glucose
D3.3.4	Type 1 and type 2 diabetes
D3.3.5	Thermoregulation
D3.3.6	Thermoregulation

D4Ecosystems (Continuity and change)

Natural selection · D4.1

Spec	What to know (the note)	Not yet	Nearly	Confident
D4.1.1	Natural selection as the mechanism of evolution
D4.1.2	Mutation and sexual reproduction as sources of variation
D4.1.3	Overproduction, competition and selection pressures
D4.1.4	Overproduction, competition and selection pressures
D4.1.5	Overproduction, competition and selection pressures
D4.1.6	Natural selection as the mechanism of evolution
D4.1.7	Sexual selection and Endler's guppies
D4.1.8	Sexual selection and Endler's guppies

Stability and change · D4.2

Spec	What to know (the note)	Not yet	Nearly	Confident
D4.2.1	Stability of natural ecosystems
D4.2.2	Stability of natural ecosystems
D4.2.3	Amazon deforestation as a possible tipping point
D4.2.4	Mesocosms and keystone species
D4.2.5	Mesocosms and keystone species
D4.2.6	Sustainable harvesting and agriculture
D4.2.7	Sustainable harvesting and agriculture
D4.2.8	Eutrophication
D4.2.9	Biomagnification of pollutants
D4.2.10	Microplastic and macroplastic pollution of the oceans
D4.2.11	Rewilding

Climate change · D4.3

Spec	What to know (the note)	Not yet	Nearly	Confident
D4.3.1	Anthropogenic causes and positive feedback
D4.3.2	Anthropogenic causes and positive feedback
D4.3.3	Boreal forest tipping point and polar habitat change
D4.3.4	Boreal forest tipping point and polar habitat change
D4.3.5	Nutrient upwelling and threats to coral reefs
D4.3.6	Poleward and upslope range shifts
D4.3.7	Nutrient upwelling and threats to coral reefs
D4.3.8	Afforestation, forest regeneration and peatland restoration

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Spec	What to know (the note)	Not yet	Nearly	Confident
B2.3.1–B2.3.4	Differentiation and stem cells
B2.3.5	Cell size and surface area-to-volume ratio
B2.3.6	Cell size and surface area-to-volume ratio