Biology B

    Pearson Edexcel
    A-Level

    Specification: 9BI0

    The PEARSON-EDEXCEL A-Level Biology B specification covers 11 topics with 78 learning objectives (9BI0). Use the topic browser below to explore subtopics, exam tips, common mistakes, and key terminology for each area of the course.

    Starting Pearson Edexcel A-Level Biology B this term? The whole specification is below, unit by unit.

    This subject will help you develop key knowledge and skills required for exam success.

    11

    Topics

    78

    Objectives

    0

    Exam Tips

    0

    Pitfalls

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    Key Features

    • Master key concepts
    • Develop exam technique
    • Apply knowledge effectively

    About Pearson Edexcel A-Level Biology B

    Pearson Edexcel A-Level Biology B is a concept-led course that explores the fundamental principles of biology through a systems-based approach. You will study topics ranging from the molecular building blocks of life to the complex interactions within ecosystems, with a strong emphasis on how biological processes work together to maintain life. The specification is structured into ten topics, each building on core themes such as energy transfer, information flow, and homeostasis.

    The course encourages you to think like a scientist, developing your ability to design experiments, analyse data, and evaluate evidence. Practical skills are integrated throughout, and you will complete a minimum of twelve core practical activities that prepare you for the written exams and a practical endorsement. The specification also highlights the relevance of biology to modern society, including applications in medicine, biotechnology, and environmental management.

    Assessment Structure

    This qualification is assessed through three written exam papers, all taken at the end of the two-year course. Paper 1 covers topics 1-5 and includes a mix of multiple-choice, short-answer, and extended-writing questions, worth 90 marks and 31% of the total. Paper 2 covers topics 6-10 and follows the same format, also worth 90 marks and 31%. Paper 3 is a synoptic paper that tests content from all topics and includes a pre-released scientific article, worth 120 marks and 38% of the total. There is no coursework; however, students must complete a minimum of twelve core practicals to achieve the Practical Endorsement, which is reported separately.

    Why Choose Pearson Edexcel?

    • Edexcel Biology B offers a clear, logical structure that helps students see the bigger picture of biology, making it easier to connect ideas across different topics.
    • The course includes a synoptic paper with a pre-released article, which develops critical reading and analysis skills highly valued by universities.
    • Edexcel provides a wide range of support materials, including past papers, mark schemes, and exemplar answers, giving students ample opportunity to practice and refine exam technique.

    Frequently Asked Questions

    Specification Topics

    11 topics

    Topic 7: Modern Genetics

    7.1 Using gene sequencing i Understand what is meant by the term genome. ii Understand how PCR can be used to amplify DNA samples, and how these samples can be used: ● to predict the amino acid sequence of proteins and possible links to genetically determined conditions, using gene sequencing. ● in forensic science, to identify criminals and to test paternity, using DNA profiling., 7.2 Factors affecting gene expression i Know that transcription factors are proteins that bind to DNA. ii Understand the role of transcription factors in regulating gene expression. iii Understand how post–transcription modification of mRNA in eukaryotic cells (RNA splicing) can result in different products from a single gene. iv Understand that gene expression can be changed by epigenetic modification, including non-coding RNA, histone modification and DNA methylation. v Know that epigenetic modification is important in ensuring cell differentiation., 7.4 Gene technology i Understand how recombinant DNA can be produced, including the role of restriction endonucleases and DNA ligase. ii Understand how recombinant DNA can be inserted into other cells, and the use of various vectors such as viruses and gene guns. iii Understand how antibiotic resistance marker genes and replica plating are used to identify recombinant cells. iv Understand how ‘knockout’ mice can be used as a valuable animal model to investigate gene function. v Understand the process of genetic modification of soya beans and how it has been used to improve production, including altering the balance of fatty acids to prevent oxidation of soya products. vi Understand why the widespread use of genetic modification of major commercial crops and other transgenic processes have caused public debate of their advantages and disadvantages. +2 more

    5 objectives5 subtopics

    Topic 4: Exchange and Transport

    4.2 Cell transport mechanisms i Know the structure of the cell surface membrane with reference to the fluid mosaic model. ii Understand how passive transport is brought about by: ● diffusion ● facilitated diffusion (through carrier proteins and protein channels) ● osmosis. iii Understand how the properties of molecules affects how they are transported, including solubility, size and charge. iv Know that large molecules can be transported into and out of cells through the formation of vesicles, in the processes of endocytosis and exocytosis., CORE PRACTICAL 7: Dissect an insect to show the structure of the gas exchange system, taking into account the safe and ethical use of organisms. ii Understand gas exchange in flowering plants, including the role of stomata, gas exchange surfaces in the leaf and lenticels., CORE PRACTICAL 6: Determine the water potential of plant cells. Water potential = turgor pressure + osmotic potential ψ = P + π +8 more

    11 objectives11 subtopics

    Topic 5: Energy for Biological Processes

    5.1 Aerobic respiration i Know that cellular respiration yields ATP which is used as a source of energy for metabolic reactions, and the process also generates heat. ii Know the different stages in aerobic respiration, including: ● glycolysis in the cytoplasm ● link reaction ● Krebs cycle ● oxidative phosphorylation in mitochondria., 5.5 Anaerobic respiration i Know that anaerobic respiration is the partial breakdown of hexoses to produce a limited yield of ATP in the absence of oxygen. ii Understand the difference in ATP yields from one molecule of hexose sugar in aerobic conditions compared with anaerobic conditions. iii Understand how lactate as a by-product of anaerobic respiration affects mammalian muscle contraction. iv Understand how anaerobic respiration in plants results in ethanol formation., 5.6 Photosynthetic pigments i Understand what is meant by absorption and action spectra. +7 more

    10 objectives10 subtopics

    Topic 2: Cells, Viruses and Reproduction of Living Things

    2.4 Sexual reproduction in mammals i Understand the processes of oogenesis and spermatogenesis. ii Understand the events of fertilisation from the first contact between the gametes to the fusion of nuclei. iii Understand the early development of the embryo to blastocyst stage., 2.3 Eukaryotic cell cycle and division i Know that the cell cycle is a regulated process in which cells divide into two identical daughter cells, and that this process consists of three main stages: interphase, mitosis and cytokinesis. ii Understand what happens to genetic material during the cell cycle, including the stages of mitosis. iii Understand how mitosis contributes to growth, repair and asexual reproduction., 2.1 Eukaryotic and prokaryotic cell structure and function i Understand that cell theory is a unifying concept that states that cells are a fundamental unit of structure, function and organisation in all living organisms. ii Understand that in complex organisms, cells are organised into tissues, organs, and organ systems. iii Know the ultrastructure of prokaryotic cells and the structure of organelles, including: nucleoid, plasmids, 70S ribosomes and cell wall. iv Be able to distinguish between Gram positive and Gram negative bacterial cell walls and understand why each type reacts differently to some antibiotics. v Know the ultrastructure of eukaryotic cells and the functions of organelles, including: nucleus, nucleolus, 80S ribosomes, rough and smooth endoplasmic reticulum, mitochondria, centrioles, lysosomes, Golgi apparatus, cell wall, chloroplasts, vacuole and tonoplast. vi Know how magnification and resolution can be achieved using light and electron microscopy. vii Understand the importance of staining specimens in microscopy. +5 more

    8 objectives8 subtopics

    Topic 1: Biological Molecules

    1.1 Carbohydrates i Know the difference between monosaccharides, disaccharides and polysaccharides. ii Know the structure of the hexose glucose (alpha and beta) and the pentose ribose. iii Understand how monosaccharides (glucose, fructose, galactose) join to form disaccharides (sucrose, lactose and maltose) and polysaccharides (starch formed from amylose and amylopectin; glycogen) through condensation reactions forming glycosidic bonds, and how these can be split through hydrolysis reactions. iv Understand how the structure of glucose, starch, glycogen and cellulose relates to their function., 1.5 Enzymes i Know the structure of enzymes as globular proteins. ii Understand the concepts of specificity and the induced fit hypothesis. iii Understand that enzymes are catalysts that reduce activation energy. iv Understand how temperature, pH, substrate and enzyme concentration affect the rate of enzyme activity., 1.4 DNA and protein synthesis i Know the structure of DNA, including the structure of the nucleotides (purines and pyrimidines), base pairing, the two sugar-phosphate backbones, phosphodiester bonds and hydrogen bonds. ii Understand how DNA is replicated semi-conservatively, including the role of DNA helicase, polymerase and ligase. iii Know that a gene is a sequence of bases on a DNA molecule coding for a sequence of amino acids in a polypeptide chain. iv Know the structure of mRNA including nucleotides, the sugar phosphate backbone and the role of hydrogen bonds. v Know the structure of tRNA, including nucleotides, the role of hydrogen bonds and the anticodon. vi Understand the processes of transcription in the nucleus and translation at the ribosome, including the role of sense and anti-sense DNA, mRNA, tRNA and the ribosomes. vii Understand the nature of the genetic code, including triplets coding for amino acids, start and stop codons, degenerate and non-overlapping nature, and that not all the genome codes for proteins. viii Understand the term gene mutation as illustrated by base deletions, insertions and substitutions. ix Understand the effect of point mutations on amino acid sequences, as illustrated by sickle cell anaemia in humans. +5 more

    8 objectives8 subtopics

    Topic 10: Ecosystems

    10.1 The nature of ecosystems i Understand what is meant by the term ecosystem and that they range in size. ii Understand what is meant by trophic levels. iii Understand the advantages and disadvantages of pyramids of numbers, biomass (dry) and energy as useful representations of ecosystem structure and how biomass and energy are transferred within them. iv Know the ecological techniques used to assess abundance and distribution of organisms in a natural habitat, including types of quadrat, transects, ACFOR scales, percentage cover and individual counts. v Be able to select appropriate ecological techniques according to the ecosystem and organisms to be studied., 10.3 Changes in ecosystems i Understand how ecosystems can develop over time, including use of the terms colonisation and succession and types of climax communities. ii Understand the effects of biotic and abiotic factors on population size., CORE PRACTICAL 15: Investigate the effect of different sampling methods on estimates of the size of a population taking into account the safe and ethical use of organisms. vi Be able to use statistical tests to analyse data, including t-test and Spearman rank correlation coefficient. +3 more

    6 objectives6 subtopics

    Topic 6: Microbiology and Pathogens

    6.3 Action of antibiotics i Understand the action of bactericidal and bacteriostatic antibiotics, as illustrated by penicillin and tetracycline., 6.7 Response to infection i Know the mode of action of macrophages, neutrophils and lymphocytes. ii Understand the development of the humoral immune response, including the role of: ● antigen presenting T cells ● T helper cells and cytokines ● B cells ● clonal selection ● plasma cells ● antibodies. iii Understand the development of the cell-mediated immune response including the role of: ● antigen presenting cells ● T helper cells and cytokines ● T killer cells., 6.6 Problems of controlling endemic diseases i Understand the social and economic and ethical implications of different control methods for endemic malaria and the role of the scientific community in validating these methods. +7 more

    10 objectives10 subtopics

    Topic 9: Control Systems

    9.9 Osmoregulation and temperature regulation i Know the gross and microscopic structure of the mammalian kidney. ii Understand how urea is produced in the liver from excess amino acids (details of the ornithine cycle are not required) and how it is removed from the bloodstream by ultrafiltration. iii Understand how solutes are selectively reabsorbed in the proximal tubule and how the Loop of Henle acts as a counter-current multiplier to increase the reabsorption of water. iv Understand how the pituitary gland and osmoreceptors in the hypothalamus, combined with the action of antidiuretic hormone (ADH) bring about negative feedback control of mammalian plasma concentration. v Understand how the kidney of a kangaroo rat ( Dipodomys sp .) is adapted for life in a dry environment. vi Understand that an endotherm is able to produce heat through metabolic processes but an ectotherm must rely on the external environment. vii Understand how an endotherm is able to regulate its temperature through behaviour, and also physiologically through the autonomic nervous system, including the role of thermoreceptors, hypothalamus and the skin., 9.2 Chemical control in mammals i Understand the principles of mammalian hormone production by endocrine glands and their mode of action involving receptors on target cells. ii Know that there are two main modes of action in hormones: ● hormones attach to receptor sites and trigger the release of a second messenger that activates specific enzymes in the cell, including adrenaline ● hormones enter cells and bind directly to transcription factors, including oestrogen., 9.6 Effects of drugs on the nervous system i Understand how the effects of drugs can be caused by their influence on synaptic transmission, including: ● nicotine (mimicking effects of acetylcholine) ● lidocaine (blocking voltage gated Na + ion channels) ● cobra venom (blocking acetylcholine receptors). +7 more

    10 objectives10 subtopics

    Topic 3: Classification and Biodiversity

    3.3 Biodiversity i Know that biodiversity can be assessed at different scales: ● within a habitat at the species level using a formula to calculate an index of diversity: D = N(N - 1) / Σn(n - 1) ● within a species at the genetic level by looking at the variety of alleles in the gene pool of a population. ii Understand the ethical and economic reasons (ecosystem services) for the maintenance of biodiversity. iii Understand the principles of ex-situ (zoos and seed banks) and in-situ conservation (protected habitats), and the issues surrounding each method., 3.2 Natural selection i Understand how evolution can come about through natural selection acting on variation bringing about adaptations. ii Understand how organisms occupy niches according to physiological, behavioural and anatomical adaptations. iii Understand how reproductive isolation can lead to allopatric and sympatric speciation. iv Understand that there is an evolutionary race between pathogens and the development of medicines to treat the diseases they cause., 3.1 Classification i Know that the classification system consists of a hierarchy of domain, kingdom, phylum, class, order, family, genus and species. ii Understand the limitations of the definition of a species as a group of organisms with similar characteristics that interbreed to produce fertile offspring. iii Understand why it is often difficult to assign organisms to any one species or to identify new species. iv Understand how gel electrophoresis can be used to distinguish between species and determine evolutionary relationships. v Know that DNA sequencing and bioinformatics can be used to distinguish between species and determine evolutionary relationships. vi Understand the role of scientific journals, the peer review process and scientific conferences in validating new evidence supporting the accepted scientific theory of evolution. vii Understand the evidence for the three-domain model of classification as an alternative to the five-kingdom model and the role of the scientific community in validating this evidence.

    3 objectives3 subtopics

    Topic 8: Origins of Genetic Variation

    8.1 Origins of genetic variation i Understand that mutations are the source of new variations and that the processes of random assortment and crossing over during meiosis give rise to new combinations of alleles in gametes. ii Understand how random fertilisation during sexual reproduction brings about genetic variation., 8.3 Gene pools i Understand that selection pressures acting on the gene pool change allele frequencies in the population, including: ● stabilising selection maintaining continuity in a population ● disruptive selection leading to changes or speciation. ii Understand that sometimes changes in allele frequencies can be the result of chance and not selection, including genetic drift., 8.3 Gene pools continued iii Understand that allele frequencies can be influenced by: ● population bottlenecks ● founder effect. iv Understand how the Hardy-Weinberg equation can be used to monitor changes in the allele frequencies in a population. +1 more

    4 objectives4 subtopics

    Assessment Objectives

    AO2: Apply knowledge and understanding of scientific ideas, processes, techniques and procedures: in a theoretical context; in a practical context; when handling qualitative data; when handling quantitative data, AO1: Demonstrate knowledge and understanding of scientific ideas, processes, techniques and procedures, AO3: Analyse, interpret and evaluate scientific information, ideas and evidence, including in relation to issues, to: make judgements and reach conclusions; develop and refine practical design and procedures

    3 objectives3 subtopics

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