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AS and A Level Biology A (Salters-Nuffield)

AS SCHEME OF WORK (CONCEPT) Scheme of work – AS Biology A (Concept)

Pearson Edexcel AS Biology A

Scheme of Work – AS Biology A (Concept)

This is an example and may be adapted.

Student Spec. Book Week Topic Content of lessons Teaching suggestions reference pages

1 Lifestyle, Health ● Understand the importance of water as a solvent in Use model beads to construct 1.2, 1.12 and Risk transport, including its dipole nature. water and carbohydrate ● Know the difference between monosaccharides, molecules. disaccharides and polysaccharides, including glycogen Use paper shapes to construct and starch (amylose and amylopectin). carbohydrate molecules. ● Be able to relate the structures of monosaccharides, disaccharides and polysaccharides to their roles in providing and storing energy (β-glucose and cellulose are not required in this topic).

2 Lifestyle, Health ● Know how monosaccharides join to form disaccharides Use immobilised lactase to 1.3, 1.4 and Risk (sucrose, lactose and maltose) and polysaccharides show hydrolysis of the (glycogen and amylose) through condensation reactions disaccharide lactose into the forming glycosidic bonds, and how these can be split monosaccharides glucose and through hydrolysis reactions. galactose. ● Know how a triglyceride is synthesised by the formation Use model beads or paper of ester bonds during condensation reactions between shapes to construct lipids. glycerol and three fatty acids. ● Know the differences between saturated and unsaturated lipids.

2 © Pearson Education Ltd 2015. Copying permitted for purchasing institution only. This material is not copyright free. Scheme of work – AS Biology A (Concept)

3 Lifestyle, Health ● Understand why many animals have a heart and Dissect sheep heart. 1.1, 1.4 and Risk circulation (mass transport to overcome limitations of Show animations of heart diffusion in meeting the requirements of organisms). action. ● Know the cardiac cycle (atrial systole, ventricular systole Look at a model heart. and cardiac diastole) and relate the structure and operation of the mammalian heart, including the major Show major blood vessels on blood vessels, to its function. model body. ● Know how the relationship between heart structure and function can be investigated practically.

4 Lifestyle, Health ● Understand how the structures of blood vessels Look at prepared slides 1.3, 1.6, and Risk (capillaries, arteries and veins) relate to their functions. showing an artery and a vein. 1.17 ● CORE PRACTICAL 1: Investigate the effect of caffeine Demonstrate elastic recoil by on heart rate in daphnia. suspending a ring of artery ● Discuss the potential ethical issues regarding the use of and vein from a hook on a invertebrates in research. clamp stand and record the length with a 10 g mass ● Understand the blood-clotting process (thromboplastin attached to the free end. release, conversion of prothrombin to thrombin and fibrinogen to fibrin) and its role in cardiovascular disease CORE PRACTICAL 1: Hold a (CVD). debate on ethics. Look at prepared microscope slides showing blood cells, including platelets.

5 Lifestyle, Health ● Understand the course of events that leads to Use ECG traces to calculate 1.5, 1.7, and Risk atherosclerosis (endothelial dysfunction, inflammatory heart rate. 1.18 response, plaque formation, raised blood pressure Look at research linking ● Know how factors such as genetic, diet, age, gender, factors to CVD and its high blood pressure, smoking and inactivity increase the treatments. risk of cardiovascular disease (CVD). ● Know the benefits and risks of treatments for cardiovascular disease (CVD) (antihypertensives, statins, anticoagulants and platelet inhibitors).

6 Lifestyle, Health ● Be able to analyse and interpret data on the possible Analyse data from research 1.15, 1.16 and Risk significance for health of blood cholesterol levels and on blood cholesterol and CVD. levels of high-density lipoproteins (HDLs) and low- Plot correlations between density lipoproteins (LDLs). cholesterol levels and CVD. ● Know the evidence for a causal relationship between Calculate coefficients. blood cholesterol levels (total cholesterol and LDL cholesterol) and cardiovascular disease (CVD). Plan a health campaign using information on lifestyle ● Understand how people use scientific knowledge about factors and coronary heart the effects of diet including obesity indicators body mass disease. index and waist-to-hip ratio, exercise and smoking to reduce their risk of coronary heart disease.

7 Lifestyle, Health ● CORE PRACTICAL 2: Investigate the vitamin C content CORE PRACTICAL 2: Look at 1.8, 1.11 and Risk of food and drink. evidence, including causality ● Be able to analyse and interpret quantitative data on versus correlations, of illness and mortality rates to determine health risks research into weight gain and (including distinguishing between correlation and loss and health risks. causation and recognising conflicting evidence). Debate and devise a plan to ● Be able to analyse data on energy budgets and diet. improve the health of the nation. ● Understand the consequences of energy imbalance, including weight loss, weight gain, and development of obesity.

8 Lifestyle, Health ● Be able to evaluate the design of studies used to Look at some original 1.9, 1.10 and Risk determine health risk factors including sample selection research using different and sample size used to collect data that is both valid designs and debate their and reliable. validity. ● Understand why people’s perceptions of risks are often Class discussion of risk different from the actual risks including underestimating perception and possible and overestimating the risks due to diet and other factors. lifestyle factors in the development of heart disease.

9 Genes and Health ● Know the structure and properties of cell membranes. Use plasticine to make 2.2, 2.3, 2.4 ● Understand how models such as the fluid mosaic model membrane models. of cell membranes are interpretations of data used to Show animations of cell develop scientific explanations of the structure and membrane structure. properties of cell membranes. Simple demonstrations of ● Understand what is meant by osmosis in terms of the osmosis using potatoes and movement of free water molecules through a partially visking tubing. permeable membrane (consideration of water potential Animations of active transport is not required). and diffusion. ● Understand what is meant by passive Simple demonstrations of transport(diffusion, facilitated diffusion), active transport passive transport e.g. (including the role of ATP as an immediate source of potassium permanganate energy), endocytosis and exocytosis. crystals in water. ● Understand the involvement of carrier and channel proteins in membrane transport.

10 Genes and Health ● Know the properties of gas exchange surfaces in living Calculate SA to V ratio for 2.1 organisms (large surface area to volume ratio, thickness different sized cubes. Use of surface, difference in concentration). different cube sizes of potato ● Understand how the rate of diffusion is dependent on to find out how SA:VOL ratio these properties and can be calculated using Fick’s Law affects percentage water of Diffusion. uptake. ● Understand how the structure of the mammalian lung is Calculate using Fick’s Law of adapted for rapid gaseous exchange. Diffusion. ● CORE PRACTICAL 3: Investigate membrane structure, Examine a mammalian lung including the effect of alcohol concentration or to show anatomy. temperature on membrane permeability. Show animations of gas exchange at lung surface.

11 Genes and Health ● Know the basic structure of an amino acid (structures of Use atomic models to 2.9 specific amino acids are not required). illustrate amino and ● Understand the formation of polypeptides and proteins carboxylic acid groups and (amino acid monomers linked by peptide bonds in some basic R groups; show condensation reactions). peptide bonds and formation of dipeptides. ● Understand the significance of a protein’s primary structure in determining its three-dimensional structure Demonstrate protein and properties (globular and fibrous proteins and the structures using wire. types of bonds involved in its three-dimensional structure). ● Know the molecular structure of a globular protein and a fibrous protein and understand how their structures relate to their functions (including haemoglobin and collagen).

12 Genes and Health ● Understand the mechanism of action and the specificity Demonstrate “lock and key” 2.10 of enzymes in terms of their three-dimensional using cardboard models and structure. animations. ● Understand that enzymes are biological catalysts that All students should carry out reduce activation energy. the core practicals. ● Know that there are intracellular enzymes catalysing reactions inside cells and extracellular enzymes produced by cells catalysing reactions outside of cells. ● CORE PRACTICAL 4: Investigate the effect of enzyme and substrate concentrations on the initial rates of reactions.

13 Genes and Health ● Know the basic structure of mononucleotides Use cardboard models of 2.5, 2.11 (deoxyribose or ribose linked to a phosphate and a base, basic units of DNA and RNA to including thymine, uracil, cytosine, adenine or guanine) show structure. and the structures of DNA and RNA (polynucleotides Display animations showing composed of mononucleotides linked through DNA structure and replication. condensation reactions). Use historical evidence from ● Know how complementary base pairing and the DNA research including hydrogen bonding between two complementary strands Meselson and Stahl’s classic are involved in the formation of the DNA double helix. experiment to formulate ● Describe DNA replication (including the role of DNA conclusion as to structure and polymerase) and how Meselson and Stahl’s classic replication of DNA. experiment provided new data which supported the accepted theory of replication of DNA and refuted competing theories. ● Understand the process of DNA replication, including the role of DNA polymerase. ● Understand how Meselson and Stahl’s classic experiment provided new data that supported the accepted theory of replication of DNA and refuted competing theories.

14 Genes and Health ● Understand the process of protein synthesis Calculate the number of 2.6, 2.7, 2.8 (transcription) including the role of RNA polymerase, products/words possible with translation, messenger RNA, transfer RNA, ribosomes 1,2,3,4 bases/letters and and the role of start and stop codons. relate to the number of amino ● Understand the roles of the DNA template (antisense) acids that exist. strand in transcription, codons on messenger RNA and Examine evidence from the anticodons on transfer RNA. discovery of DNA structure in ● Understand the nature of the genetic code (triplet code, the 1950s. non-overlapping and degenerate). Students produce PowerPoints ● Know that a gene is a sequence of bases on a DNA or animations of protein molecule that codes for a sequence of amino acids in a synthesis. polypeptide chain.

15 Genes and Health ● Understand how errors in DNA replication can give rise Discuss examples of errors in 2.12, 2.13 to mutations. DNA and resultant problems, ● Understand how cystic fibrosis results from one of a including cystic fibrosis. number of possible gene mutations. Create glossary of terms. ● Know the meaning of the terms: gene, allele, genotype, Discuss genetic pedigrees phenotype, recessive, dominant, incomplete dominance, such as the royal family and homozygote and heterozygote. haemophilia. ● Understand patterns of inheritance, including the Discuss examples of interpretation of genetic pedigree diagrams, in the monohybrid inheritance. context of monohybrid inheritance.

16 Genes and Health ● Understand how the expression of a gene mutation in Examine case studies of cystic 2.14, 2.15, people with cystic fibrosis impairs the functioning of the fibrosis sufferers. 2.16 gaseous exchange, digestive and reproductive systems. Debate ethical implications of ● Understand the uses of genetic screening, including the prenatal screening etc. identification of carriers, pre-implantation genetic diagnosis (PGD) and prenatal testing, including amniocentesis and chorionic villus sampling. ● Understand the implications of prenatal genetic screening. ● Be able to identify and discuss the social and ethical issues related to genetic screening from a range of ethical viewpoints.

17 Genes and Health Recap and consolidation of Topic 2.

18 Voice of the ● Know that all living organisms are made of cells, sharing Use plasticine and other 3.1, 3.2, Genome some common features. modelling materials to make 3.3, 3.4, 3.5 ● Know the ultrastructure of eukaryotic cells, including different cell types. nucleus, nucleolus, ribosomes, rough and smooth Examine EM images of cells endoplasmic reticulum, mitochondria, centrioles, showing different organelles. lysosomes, and Golgi apparatus. ● Understand the role of the rough endoplasmic reticulum (rER) and the Golgi apparatus in protein transport within cells, including their role in the formation of extracellular enzymes. ● Know the ultrastructure of prokaryotic cells, including cell wall, capsule, plasmid, flagellum, pili, ribosomes, mesosomes and circular DNA. ● Be able to recognise the organelles in 3.2 from electron microscope (EM) images.

19 Voice of the ● Understand the role of mitosis and the cell cycle in Use PowerPoint/animations/ 3.10, 3.13 Genome producing identical daughter cells for growth and models/pipe cleaners in asexual reproduction. student presentations of ● Understand why the cells of multicellular organisms are mitosis. organised into tissues, tissues into organs and organs All students should carry out into systems. the core practicals. ● CORE PRACTICAL 5: Understand how to prepare and stain a root tip squash to observe the stages of mitosis.

20 Voice of the ● Understand how mammalian gametes are specialised for Show animations of 3.6, 3.7, Genome their functions (including the acrosome in sperm and the fertilisation. 3.8, 3.9 zona pellucida in the egg). Use PowerPoint/animations/ ● Know the process of fertilisation in mammals, including models/pipe cleaners in the acrosome reaction, the cortical reaction and the student presentations of fusion of nuclei. meiosis. ● Know that a locus (loci) is the location of genes on a chromosome. ● Understand the linkage of genes on a chromosome and sex linkage. ● Understand the role of meiosis in ensuring genetic variation through the production of non-identical gametes as a consequence of independent assortment of chromosomes and crossing over of alleles between chromatids (details of the stages of meiosis are not required).

21 Voice of the ● Understand what is meant by the terms ‘stem cell, Use a table to compare 3.11, 3.12 Genome pluripotency and totipotency’. pluripotency and totipotency. ● Be able to discuss the way society uses scientific Debate use of stem cells in knowledge to make decisions about the use of stem cells medical therapies. in medical therapies. ● Understand how cells become specialised through differential gene expression, producing active mRNA leading to synthesis of proteins, which in turn control cell processes or determine cell structure in animals and plants including lac operon.

22 Voice of the ● Understand how phenotype is the result of an interaction Look at case studies of 3.14, 3.15 Genome between genotype and the environment. phenotypes being affected by ● Know how epigenetic changes (including DNA the environment. methylation and histone modification) can modify the Show examples of multi allelic activation of certain genes. inheritance. ● Understand how epigenetic changes can be passed on following cell division. ● Understand how some phenotypes are affected by multiple alleles for the same gene at many loci (polygenic inheritance) as well as the environment and how this can give rise to phenotypes that show continuous variation.

23 Voice of the Recap and consolidation of Topic 3. Genome

24 Biodiversity and ● Know the ultrastructure of plant cells (cell walls, Use prepared slides of plant 4.7, 4.8, 4.9 Natural chloroplasts, amyloplasts, vacuole, tonoplast, tissues and electron Resources plasmodesmata, pits and middle lamella) and be able to microscope (EM) images of compare it with animal cells. plant tissue to show different ● Be able to recognise the organelles in 4.7 from electron plant organelles. microscope (EM) images. Show diagrams of structure of ● Understand the structure and function of the cellulose vs starch illustrate polysaccharides starch and cellulose, including the role structure related to function. of hydrogen bonds between β-glucose molecules in the formation of cellulose microfibrils.

25 Biodiversity and ● Understand how the arrangement of cellulose microfibrils Use prepared slides of plant 4.10, 4.11 Natural and secondary thickening in plant cell walls contributes tissue to show xylem and Resources to the physical properties of xylem vessels and phloem etc. Examine different sclerenchyma fibres in plant fibres that can be exploited aged sections through plant by humans. stems. Illustrate ● Know the similarities and differences between the dendrochronology using structures, position in the stem and function of different aged stems of trees sclerenchyma fibres (support), xylem vessels (support etc. and transport of water and mineral ions) and phloem All students should carry out (translocation of organic solutes). the core practicals. ● CORE PRACTICAL 6: Identify sclerenchyma fibres, phloem sieve tubes and xylem vessels and their location within stems through a light microscope. ● CORE PRACTICAL 8: Determine the tensile strength of plant fibres practically.

26 Biodiversity and ● Understand the importance of water and inorganic ions Research and presentations 4.12, 4.15 Natural (nitrate, calcium ions and magnesium ions) to plants. by students on the use of Resources ● Understand how the uses of plant fibres and starch may plant-based products. contribute to sustainability, including plant-based All students should carry out products to replace oil-based plastics. the core practicals. ● CORE PRACTICAL 7: Understand how to investigate plant mineral deficiencies practically.

27 Biodiversity and ● Understand the development of drug testing from Look at historical descriptions 4.13, 4.14 Natural historic to contemporary protocols, including William of drug testing, including Resources Withering’s digitalis soup, double blind trials, placebo, William Withering’s work. three-phased testing. All students should carry out ● Understand the conditions required for bacterial growth. the core practicals. ● CORE PRACTICAL 9: Investigate the antimicrobial properties of plants, including aseptic techniques for the safe handling of bacteria.

28 Biodiversity and ● Know that over time the variety of life has become Examine historical studies of 4.1, 4.2 Natural extensive but is now being threatened by human life on earth. Resources activity. Use data to calculate the ● Understand the terms biodiversity and endemism. heterozygosity index and ● Know how biodiversity can be measured within a habitat Simpson’s index. using species richness and within a species using genetic diversity by calculating the heterozygosity index (H): number of heterozygotes H  number of individuals in the population ● Know how biodiversity can be compared in different habitats using Simpson’s diversity index (D): N(N  1) (D)   n(n  1)

29 Biodiversity and ● Understand the concept of niche and be able to discuss Look at examples of niche 4.3, 4.4, 4.5 Natural examples of adaptation of organisms to their e.g. bird feeding behaviours Resources environment (behavioural, physiological and and beak types. anatomical). Calculate using data and the ● Understand how natural selection can lead to adaptation Hardy-Weinberg equation. and evolution. Examine case studies of ● Understand how the Hardy-Weinberg equation can be isolation and speciation. used to see whether a change in allele frequency is occurring in a population over time. ● Understand that reproductive isolation can lead to accumulation of different genetic information in populations potentially leading to the formation of new species.

30 Biodiversity and ● Understand that classification is a means of organising Discuss examples of 4.6, 4.16 Natural the variety of life based on relationships between classification on the basis of Resources organisms using differences and similarities in genotype and phenotype. phenotypes and in genotypes, and is built around the Debate/discuss the three species concept. domain approach to ● Understand the process and importance of critical classification. evaluation of new data by the scientific community, Visit a zoo or seed bank to which leads to new taxonomic groupings, including the explore breeding three domains of life based on molecular phylogeny, programmes. which are Bacteria, Archaea, Eukaryota. ● Be able to evaluate the methods used by zoos and seed banks in the conservation of endangered species and their genetic diversity, including scientific research, captive breeding programmes, reintroduction programmes and education.