This document compares the specification learning outcomes from the legacy GCSE Twenty century Biology qualification to the new GCSE (9-1) in Twenty first century Biology. It shows where the statements in the old specification are covered in the new spec, indicates where they are no longer assessed and highlights where new content has been added. Spec Ref Original spec statement (21C current spec) Spec Ref Spec statement equivalent (reformed 21C spec) tick if no longer covered B1.1.1 recall that instructions to control how an organism develops and functions are in the nucleus of its cells and are called genes B1.1.1 B1.1.5 a) explain how the nucleus and genetic material of eukaryotic cells (plants and animals) and the genetic material, including plasmids, of prokaryotic cells are related to cell functions b) describe how to use a light microscope to observe a variety of plant and animal cells explain the terms chromosome, gene, allele, variant, genotype and phenotype B1.1.2 recall that are instructions for a cell that describe how to make proteins B1.1.6 explain the importance of amino acids in the synthesis of proteins, including the genome as instructions for the polymerisation of amino acids to make proteins B1.1.3 recall that proteins may be structural (e.g. collagen) or functional (e.g. enzymes such as amylase) B1.1.6 explain the importance of amino acids in the synthesis of proteins, including the genome as instructions for the polymerisation of amino acids to make proteins B1.1.4 recall that genes are sections of very long DNA molecules that make up chromosomes in the nuclei of cells B1.1.5 explain the chromosome, gene, allele, variant, genotype and phenotype
B1.1.5 understand that some characteristics are determined by genes (e.g. dimples), some are determined by environmental factors (e.g. scars), and some are determined by a combination of genes and the environment (e.g. weight) B1.1.2 B1.1.4 describe the genome as the entire genetic material of an organism describe simply how the genome and its interaction with the environment influence the development of the phenotype of an organism, including the idea that most characteristics depend on instructions in the genome and are modified by interaction of the organism with its environment. B1.1.6 understand that many characteristics are determined by several genes working together (e.g. eye colour) B1.2.6 recall that most phenotypic features are the result of multiple rather than single gene inheritance NOTE: learners are not expected to describe epistasis and its effects B1.2.1 recall that body cells contain pairs of chromosomes and that sex cells contain only one chromosome from each pair B1.2.8 describe sex determination in humans B1.2.2 understand that chromosomes in a pair carry the same genes in the same place, but that there may be different versions of genes called alleles B1.1.5 explain the chromosome, gene, allele, variant, genotype and phenotype B1.2.3 recall that an individual usually has two alleles for each gene B1.2.2 explain single gene inheritance, including dominant and recessive alleles and use of genetic diagrams B1.2.4 recall that in an individual the two alleles of each gene can be the same (homozygous) or different (heterozygous) B1.2.1 explain the terms gamete, homozygous, heterozygous, dominant and recessive B1.2.5 understand that during sexual reproduction genes from both parents come together and produce variation in the offspring NA NA  B1.2.6 understand that offspring have some similarities to parents because of the combination of maternal and paternal alleles in the fertilised egg B1.2.2 explain single gene inheritance, including dominant and recessive alleles and use of genetic diagrams B1.2.7 understand that different offspring from the same parents can differ from each other because they inherit a different combination of maternal and paternal alleles B1.2.3 predict the results of single gene crosses
B1.2.8 understand that an allele can be dominant or recessive, and that: a. an individual with one or both dominant alleles (in a pair of alleles) will show the associated dominant characteristic b. an individual with one recessive allele (in a pair of alleles) will not show the associated recessive characteristic c. an individual with both recessive alleles (in a pair of alleles) will show the associated recessive characteristic B1.2.2 B1.2.4 B1.2.5 B1.2.6 explain single gene inheritance, including dominant and recessive alleles and use of genetic diagrams use direct proportions and simple ratios in genetic crosses use the concept of probability in predicting the outcome of genetic crosses recall that most phenotypic features are the result of multiple genes rather than single gene inheritance B1.2.9 recall that human males have XY sex chromosomes and females have XX sex chromosomes B1.2.8 describe sex determination in humans B1.2.10 understand that the gene on the Y chromosome triggers the development of testes, and that in the absence of a Y chromosome ovaries develop B1.2.8 describe sex determination in humans B1.2.11 use and interpret genetic diagrams (family trees and Punnett squares) showing: a. the inheritance of single gene characteristics with a dominant and recessive allele b. the inheritance of sex chromosomes B1.2.2 explain single gene inheritance, including dominant and recessive alleles and use of genetic diagrams B1.2.12 understand that the term genotype describes the genetic make-up of an organism (the combination of alleles), and the term phenotype describes the observable characteristics that the organism has B1.1.5 explain the terms chromosome, gene, allele, variant, genotype and phenotype B1.3.1 understand that a small number of disorders are caused by faulty alleles of a single gene, including Huntington’s disease and cystic fibrosis B1.3.1 discuss the potential importance for medicine of our increasing understanding of the human genome, including the discovery of alleles associated with diseases and the genetic testing of individuals to inform family planning and healthcare B1.3.2 recall that disorders may be caused by dominant alleles (e.g. Huntington’s disease) or recessive alleles (e.g. cystic fibrosis) NA NA 
B1.4.1 understand that bacteria, plants and some animals can reproduce asexually to form clones (individuals with identical genes) NA NA  B1.4.2 understand that any differences between clones are likely to be due only to environmental factors NA NA  B1.4.3 understand that clones of plants occur naturally when plants produce bulbs or runners NA NA  B1.4.4 understand that clones of animals occur: a. naturally, when cells of an embryo separate (identical twins) b. artificially, when the nucleus from an adult body cell is transferred to an empty unfertilised egg cell NA NA  B1.4.5 understand that there are different types of stem cells: a. adult stem cells which are unspecialised cells that can develop into many, but not all, types of cells b. embryonic stem cells which are unspecialised cells that can develop into any type of cell B4.3.4 describe the function of stem in embryonic and adult animals and meristems in plants B1.4.6 understand that, as a result of being unspecialised, stem cells from embryos and adults offer the potential to treat some illnesses B4.3.5 explain the importance of cell differentiation, in which cells become specialised by switching genes off and on to form tissues with particular functions B1.4.7 understand that the majority of cells of multicellular organisms become specialised during the early development of the organism B4.3.5 explain the importance of cell differentiation, in which cells become specialised by switching genes off and on to form tissues with particular functions B2.1.1 understand that symptoms of an infectious disease are caused by damage done to cells by microorganisms or the poisons (toxins) they produce NA B2.1.2 understand why, in suitable conditions such as those inside a human body, microorganisms (e.g. bacteria and viruses) can reproduce rapidly to produce very large numbers NA B2.1.3 calculate the population growth of microorganisms appropriate data B2.4.3 calculate cross-sectional areas of bacterial cultures and of clear zones around antibiotic discs on agar jelly using πr2 M5c PAG7
B3.1.15 understand how carbon is recycled through the environment to include the processes of combustion, respiration, photosynthesis and decomposition B3.3.9, B3.3.10 recall that many different substances cycle through the abiotic and biotic components of an ecosystem, including carbon and water explain the importance of the carbon cycle and the water cycle to living organisms B3.1.16 understand the importance of the role of microorganisms in the carbon cycle B3.3.11 explain the role of microorganisms in the cycling of substances through an ecosystem B3.1.17 understand how nitrogen is recycled through the environment in the processes of: a. nitrogen fixation to form nitrogen compounds including nitrates b. conversion of nitrogen compounds to protein in plants and animals c. transfer of nitrogen compounds through food chains d. excretion, death and decay of plants and animals resulting in release of nitrates into the soil e. uptake of nitrates by plants f. denitrification i Foundation tier candidates are not expected to recall details of conversion of atmospheric nitrogen to nitrates, or nitrates to atmospheric nitrogen B3.3.9 NA B3.1.18 understand the importance of the role of microorganisms in the nitrogen cycle, including decomposition, nitrogen fixation and denitrification B3.3.11 explain the role of microorganisms in the cycling of substances through an ecosystem B3.1.19 interpret simple diagrams of the carbon cycle and nitrogen cycle i Foundation tier candidates are not expected to recall nitrogen fixation or denitrification NA NA  B3.1.20 understand how environmental change can be measured using non-living indicators, including nitrate levels, temperature and carbon dioxide levels NA NA  B3.1.21 understand how climate and environmental change can be measured living indicators, including phytoplankton, lichens and aquatic river organisms such as mayfly nymphs NA NA  B3.1.22 interpret data obtained from living and non-living indicators to investigate environmental change. NA NA 
B5.3.9 understand that adult stem cells and embryonic stem cells have the potential to produce cells needed to replace damaged tissues B4.5.1 discuss potential benefits, risks and ethical issues associated with the use of stem cells in medicine B5.3.10 understand that ethical decisions need to be taken when using embryonic stem cells and that this work is subject to Government regulation B4.5.1 discuss potential benefits, risks and ethical issues associated with the use of stem cells in medicine B5.3.11 understand that, in carefully controlled conditions of mammalian cloning, it is possible to reactivate (switch on) inactive in the nucleus of a body cell to form cells of all tissue types B4.5.1 discuss potential benefits, risks and ethical issues associated with the use of stem cells in medicine B6.1.1 recall that a stimulus is a change in the environment of an organism NA NA  B6.1.2 understand that simple reflexes produce rapid involuntary responses to stimuli B5.2.3 a) explain how the structure of a reflex arc, including the relay neuron, is related to its function b) describe practical investigations into reflex actions B6.1.3 understand that the simplest animals rely on reflex actions for the majority of their behaviour NA NA  B6.1.4 understand that these reflex actions help to ensure that the simplest animals respond to a stimulus in a way that is most likely to result in their survival, to include finding food and sheltering from predators NA NA  B6.1.5 recall examples of simple reflexes in humans, to include newborn reflexes (e.g. stepping, grasping, sucking), reflex, knee jerk and dropping a hot object NA NA  B6.1.6 understand that nervous including simple reflexes, requires: a. receptors to detect stimuli b. processing centres to receive information and coordinate responses c. effectors to produce the response B5.2.1 explain how the components of the nervous system work together to enable it to function, including sensory receptors, sensory neurons, the CNS, motor neurons and effectors
B6.2.15 understand that Ecstasy (MDMA) blocks the sites in the brain’s synapses where the transmitter substance, serotonin, is removed NA NA  B6.2.16 understand that the effects of Ecstasy on the nervous system are due to the subsequent increase in serotonin concentration NA NA  B6.2.17 recall that the cerebral cortex is the part of our most concerned with intelligence, memory, language and consciousness B5.2.4 describe the structure and function of the brain and roles of the cerebral cortex (intelligence, memory, language and consciousness), cerebellum (conscious movement) and brain stem (regulation of heart and breathing rate) B6.2.18 understand that scientists can map the regions of the brain to particular functions (including studies of patients with brain damage, studies in which different parts of the brain are stimulated electrically, and brain scans such as MRI, showing brain structure and activity) B5.2.4 describe the structure and function of the brain and roles of the cerebral cortex (intelligence, memory, language and consciousness), cerebellum (conscious movement) and brain stem (regulation of heart and breathing rate) B6.3.1 understand that a reflex response to a new stimulus can be learned by introducing the secondary (new) stimulus in association with the primary stimulus, and that this is called conditioning NA NA  B6.3.2 describe and explain two examples of conditioning, including Pavlov’s dogs NA NA  B6.3.3 understand that in a conditioned reflex the final response (e.g. salivation) has no direct connection to the secondary stimulus (e.g. ringing of a bell) NA NA  B6.3.4 understand that conditioned reflexes are a form of simple learning that can increase an animal’s chance of survival NA NA  B6.3.5 recall that in some circumstances the brain can modify a reflex response via a neuron to the motor neuron of the reflex arc, for example keeping hold of a hot object B5.2.3 a) explain how the structure of a reflex arc, including the relay neuron, is related to its function b) describe practical investigations into reflex actions B6.4.1 understand that the evolution of a larger brain gave early humans a better chance of survival NA NA 