IGCSE Biology (0610) Practical Opportunities Opportunities for Practical Activities

Transcription

1 IGCSE Bilgy (0610) Practical Opprtunities Opprtunities fr Practical Activities Syllabus reference Sectin1: characteristics and classificatin f living rganisms (5% teaching time) 1. Characteristics f living rganisms List and describe the characteristics f living rganisms Define the terms: nutritin; excretin; respiratin; sensitivity; reprductin; grwth; mvement Paper cards t match terms and definitins. Psters. Use f letters MRS GREN t remember terms 2.1 Cncept and use f a classificatry system Define and describe the binmial system f naming species as a system in which the scientific name f an rganism is made up f tw parts shwing the genus and species List the main features f the fllwing vertebrates: bny fish, amphibians, reptiles, birds and mammals Quick check right r wrng cards. Cards f animals - vertebrate phtgraphs. Visit t lcal z r nature reserve. Knw that there are ther classificatin systems e.g. cladistics (based n RNA/ DNA sequencing data) List the main features used in the classificatin f the fllwing grups: viruses, bacteria and fungi, and their adaptatin t the envirnment, as apprpriate Shw examples f spiled fruit, leaves Psters. size / measurement exercise frm phtmicrgraphs

2 2.2 Adaptatins f rganisms t their envirnment List the main features used in the classificatin f the fllwing grups: flwering plants (mnctyledns and eudictyledns (dictyledns)), arthrpds (insects, crustaceans, arachnids and myriapds), annelids, nematdes and mlluscs Identificatin f lcal plants which are available living specimens. Quiz t identify and classify animals frm preserved and /r specimens r illustratins 3. Simple keys Use simple dichtmus keys based n easily identifiable features Specimens f leaves r shells t prepare a simple key and t practise using keys frm past exam papers.

3 Sectin 11: Organisatin and maintenance f the rganism. (50% teaching time) 1. Cell structure and rganisatin State that living rganisms are made f cells Identify and describe the structure f a plant cell (palisade cell) and an animal cell (liver cell), as seen under a light micrscpe Describe the differences in structure between typical animal and plant cells Psters; if pssible use f micrscpe r biviewers t lk at palisade cells, liver cells. Phtmicrgraphs. Websites eg Paper cards t match structure and functin. Drawings f rganelles fr psters. Relate the structures seen under the light micrscpe in the plant cell and in the animal cell t their functins

4 2. Levels f rganisatin Relate the structure f the fllwing t their functins: Use f psters; ciliated cells in respiratry tract images frm websites; rt hair cells absrptin biviewers, xylem vessels cnductin and supprt muscle cells cntractin red bld cells transprt use f light micrscpe t view specimens. Define: tissue; rgan; rgan system. 3. Size f specimens Calculate magnificatin and size f bilgical specimens using millimetres as units Opprtunity in previus sectin t practice calculating magnificatin and t be aware f size f cells and measurement in millimetres. T be aware that sme illustratins may be reduced in size. Triangular diagram D/A/M; magnificatin = drawing size actual size use f x fr times withut unit

5 4. Mvement in and ut f cells 4.1 Diffusin Define diffusin. Describe the imprtance f diffusin f gases and slutes and f water as a slvent Diffusin f alkaline [ammnia] r acidic gases alng clsed glass tubes using apprpriate clured litmus paper. Diffusin f clured liquids in gel / agar. Ptassium permanganate crystals disslving in water. 4.2 Active Transprt Define active transprt. Discuss the imprtance f active transprt. 4.3 Osmsis Define smsis. Describe the imprtance f smsis in the uptake f water by plants, and its effects n plant and animal tissues Describe and explain the imprtance f a water ptential gradient in the uptake f water by plants [1] Plant tissue eg ptat r ther tissue in salt / sugar slutins f different cncentratin measure mass r length f pieces; [2] Destructin f membranes by leakage f clured plant sap eg beetrt sectins. Observe plasmlysis in red nin cells if micrscpe available r n vide. Use f visking tubing t represent cell membrane.

6 5. Enzymes Define the term catalyst. Define enzymes as prteins that functin as bilgical catalysts Investigate and describe the effect f changes in temperature and ph n enzyme activity Explain enzyme actin in terms f the lck and key mdel Explain the effect f changes in temperature and ph n enzyme activity Describe the rle f enzymes in the germinatin f seeds, and their uses in bilgical washing prducts and in the fd industry (including pectinase and fruit juice) Outline the use f micrrganisms and fermenters t manufacture the antibitic penicillin and enzymes fr use in bilgical washing pwders Use f cardbard mdels jigsaw pieces t fit tgether. Experimental investigatin n [i] temperature; [ii] ph using buffers n catalase [ frm fresh plant f animal tissue] / amylase [diastase] / prtease eg trypsin / lipase/ rennin / pectinase / r ther available enzyme. Prvide a set f results t wrk n if shrt f time. Imprtant that planning f an enzyme investigatin is carried ut s hw t cntrl variables and safety factrs are fully realised. Practical germinatin f seeds shwing activity f enzymes frm seeds breaking dwn starch in agar plates; r extracting enzymes frm ctyledns and breaking dwn starch in slutins; Pectinase n fruit pulp and filtering juice + and enzyme; Washing pwder activity n prtein stains eg egg ylk [ care needed] Large flasks can be used t shw simple labratry fermenters. Describe the rle f the fungus Penicillium in the prductin f antibitic penicillin

7 6. Nutritin 6.1 Nutrients List the chemical elements that make up: carbhydrates Making mlecular mdels; link up t make plymers Psters giving examples f cmmn fds fats prteins Describe the synthesis f large mlecules frm smaller basic units simple sugars t starch and glycgen amin acids t prteins fatty acids and glycerl t fats and ils Describe tests fr: starch (idine slutin) T carry ut the tests n pure substances and n different fds. It is imprtant t be able t prepare the crushed r extracted fd materials fr cmparative testing. Stress safety aspects f handling the reagents. Explain use f dip sticks Clinistix and Albustix. used in health clinic testing f urine. Estimatin f vitamin C with clured slutins eg DCPIP cmpare ascrbic acid with fruit juices. reducing sugars (Benedict s slutin) prtein (biuret test) fats (ethanl) Prepare yghurt using a starter btained cmmercially. Cllect fd labels. Discuss purpse f labelling. Discuss hazards details n labels re nut allergy, phenylalanine, etc List the principal surces f, and describe the imprtance f: carbhydrates; fats; prteins; vitamins (C and D nly); mineral salts T separate by water chrmatgraphy the different cmpnent clurs in cmmn fd clurings

8 (calcium and irn nly); fibre (rughage); water. Describe the deficiency symptms fr: vitamins (C and D nly) mineral salts (calcium and irn nly Describe the use f micrrganisms in the fd industry, with reference t yghurt and single cell prtein Describe the uses, benefits and health hazards assciated with fd additives, including clurings

9 6.2 Plant nutritin Phtsynthesis Define phtsynthesis as the fundamental prcess by which plants manufacture carbhydrates frm raw materials using energy frm light State the wrd equatin fr the prductin f simple sugars and xygen Investigate the necessity fr chlrphyll, light and carbn dixide fr phtsynthesis, using apprpriate cntrls Describe the intake f carbn dixide and water by plants T use a simple apparatus eg inverted filter funnel t demnstrate and cllect xygen bubbles frm water weed. Mdify t shw effect f clur f light using cellulid filters; the intensity by mving a lamp clser and a heat shield; carbn dixide by adding salts t water. T carry ut a starch test n a leaf using a green leaf and a variegated leaf. Keep the leaf in the dark fr 12 hurs t destarch. T find the effect f lack f light n frmatin f starch by masking an area. Use f hydrgencarbnate indicatr bserve change frm red t purple by phtsynthesising plant. Explain that chlrphyll traps light energy and cnverts it int chemical energy fr the frmatin f carbhydrates and their subsequent strage State the balanced equatin fr phtsynthesis in symbls Investigate and state the effect f varying light intensity, carbn dixide cncentratin and temperature n the rate f phtsynthesis (e.g. in submerged aquatic plants) Define the term limiting factr. Opprtunity t visit lcal plant nursery.

10 Explain the cncept f limiting factrs in phtsynthesis Explain the use f carbn dixide enrichment, ptimum light and ptimum temperatures in glasshuse systems Leaf structure Identify and label the cuticle, cellular and tissue structure f a dictylednus leaf, as seen in crss-sectin under the light micrscpe, and describe the significance f these features in terms f functins, t include:. T prepare surface views f epidermis t shw distributin f stmata stmatal index. Use f biviewers r micrscpes t bserve sectins f leaves Lk at images n web sites r bks. Psters distributin f chlrplasts phtsynthesis stmata and mesphyll cells gas exchange vascular bundles (xylem and phlem) transprt and supprt

11 6.2.3 Mineral requirements Describe the imprtance f: nitrate ins fr prtein synthesis Set up a simple mineral nutritin experiment with cntrls t grw cereal seedlings fr a few weeks magnesium ins fr chlrphyll synthesis Describe the uses, and the dangers f veruse, f nitrgen fertilisers Explain the effects f nitrate in and magnesium in deficiency n plant grwth 6.3 Animal nutritin Diet State what is meant by the term balanced diet and describe a balanced diet related t age, sex and activity f an individual Describe the effects f malnutritin in relatin t starvatin, crnary heart disease, cnstipatin and besity Energy cntent f fd.- simple calrimetry. Cmpare with calrimeter illustratin. Pster wrk. Refer t certain case studies re malnutritin. Cmpare energy cntent f different fds. Data can be fund n fd labels.

12 6.3.2 Fd supply Discuss ways in which the use f mdern technlgy has resulted in increased fd prductin. Map surce f fd available in area and mark n wrld map. Refer t air miles. Discuss the prblems f wrld fd supplies Discuss the prblems which cntribute t famine Human alimentary canal Define ingestin. Define egestin. Identify the main regins f the alimentary canal and assciated rgans. Describe the functins f the regins f the alimentary canal. Paper cards t identify regins n large wall sized diagram f alimentary canal r mdel trs. Paper dmines t match regin and functin.

13 6.3.4 Mechanical and physical digestin Define digestin. Identify the types f human teeth and describetheir structure and functins State the causes f dental decay and describe the prper care f teeth Describe the prcess f chewing Describe the rle f lngitudinal and circular muscles in peristalsis Use mirrrs t check wn teeth, cmpare with the ideal set. Mdels r diagrams t explain structure f teeth. Swabs f teeth and saliva tested with indicatr t shw ph. [safety disinfectant t dispse f used equipment] Observe diagrams r specimens f different animals teeth. [museum visit] Observe data n use f fluride. Lk at additins t different tthpastes which are available. Pster wrk. Use f mdel trs. Demnstratin f blus [ ball] passing thrugh tubing rubber tubing r sck r stcking. Outline the rle f bile in emulsifying fats. Describe hw fluride reduces tth decay and explain arguments fr and against the additin f fluride t public water supplies

14 6.3.5 Chemical digestin State the significance f chemical digestin in the alimentary canal in prducing small, sluble mlecules that can be absrbed State where, in the alimentary canal, amylase, prtease and lipase enzymes are secreted State the functins f a typical amylase, a prtease and a lipase, listing the substrate and end-prducts Paper mdels f mlecules cut apart int mnmers. Amylase breakdwn f starch using Idine test. Link with mdel gut using visking tubing. Prtease with milk breakdwn f casein in milk r gelatine n phtgraphic film r fresh meat Breakdwn f fats t frm acids with help f bile salts litmus r ph indicatr Absrptin Define absrptin as mvement f digested fd mlecules thrugh the wall f the intestine int the bld r lymph Identify the small intestine as the regin fr the absrptin f digested fd Biviewers and micrscpe t study wall f small intestine. Psters t reinfrce uptake int bld r lymph. Describe the significance f villi in increasing the internal surface area f the small intestine Describe the structure f a villus. State the rle f the hepatic prtal vein in the transprt f absrbed fd t the liver Use f data t prvide pprtunity t reinfrce understanding f vlumes invlved.

15 Identify the rle f the small intestine and cln in absrptin f water Assimilatin Define assimilatin. Describe the rle f the liver in the metablism f glucse (glucse glycgen) and amin acids (amin acids prteins and destructin f excess amin acids) Describe the rle f fat as an energy strage substance Trs r large diagram t demnstrate psitin and size f liver. [link back cell structure]. Pster wrk t summarise digestin. Define deaminatin. State that the liver is the site f breakdwn f alchl and ther txins Mlecular mdels r paper mdels t demnstrate deaminatin.

16 7. Transprtatin 7.1 Transprt in plants State the functins f xylem and phlem Identify the psitins f xylem and phlem tissues as seen in transverse sectins f unthickened, herbaceus, dictylednus rts, stems and leaves Examine whle yung herbaceus dictylednus plants t bserve rts and aerial parts. Grw frm seed in pts [ link with later sectins n grwth and germinatin]. Use f biviewers r micrscpes with prepared slides. Phtmicrgraphs Water uptake Identify rt hair cells, as seen under the light micrscpe, and state their functins State the pathway taken by water thrugh rt, stem and leaf (rt hair, rt crtex cells, xylem, mesphyll cells) Investigate, using a suitable stain, the pathway f water thrugh the abve-grund parts f a plant Observe rt hairs n plants and use hand lens. View under micrscpe r in phtmicrgraphs. Pster wrk. Test the uptake f dyes such as methylene blue r esin in freshly cut petiles f celery r pale clured stems r germinated seedlings eg mung beans. Relate the structure and functins f rt hairs t their surface area and t water and in uptake

17 7.1.2 Transpiratin Define transpiratin Describe hw water vapur lss is related t cell surfaces, air spaces and stmata Describe the effects f variatin f temperature, humidity and light intensity n transpiratin rate Describe hw wilting ccurs Explain the mechanism f water uptake and mvement in terms f transpiratin prducing a tensin ( pull ) frm abve, creating a water ptential gradient in the xylem, drawing chesive water mlecules up the plant. Use f biviewers r micrscpes t bserve TS sectin f leaf. Phtmicrgraphs. Pster wrk t fllw pathway. Preparatin f epidermis t shw surface view f stmata wax impressin, r peel f nail varnish layer. Sme leaves are easier than thers t tear in rder t btain a separate epidermis t study. Trandescantia, [has different clured guard cells cmpared with epidermis;] Pepernia. Leave cut sht withut water fr wilting. Use f ptmeter r flasks n tp pan balance t shw water lss in mass under different cnditins. Use f capillarity tubing ptmeter t measure rate f water uptake t quantify this rate f water uptake. Observe leaves f succulents, water weeds. Discuss the adaptatins f the leaf, stem and rt t three cntrasting envirnments, t include pnd, garden and desert, with emphasis n lcal examples (where apprpriate) and the factrs described in the cre

18 7.1.3 Translcatin Define translcatin in terms f the mvement f sucrse and amin acids in phlem; frm regins f prductin t regins f strage OR t regins f utilisatin in respiratin r grwth Pster wrk.use f biviewers r micrscpes t study phlem. Cut bark f tree n ne side t bserve sap escaping. Analyse sap fr sugars r test stickiness. Describe translcatin thrughut the plant f applied chemicals, including systemic pesticides Cmpare the rle f transpiratin and translcatin in the transprt f materials frm surces t sinks, within plants at different seasns 7.2 Transprt in humans Describe the circulatry system as a system f tubes with a pump and valves t ensure ne-way flw f bld Describe the duble circulatin in terms f a lw pressure circulatin t the lungs and a high pressure circulatin t the bdy tissues and relate these differences t the different functins f the tw circuits Large diagram f circulatin f bld system. Mdel trs t demnstrate. Use f vide.

19 7.2.1 Heart Describe the structure f the heart. Describe the functin f the heart in terms f muscular cntractin and the wrking f the valves Investigate, state and explain the effect f physical activity n pulse rate Describe crnary heart disease Arteries, veins and capillaries Name the main bld vessels t and frm the heart, lungs, liver and kidney Describe the structure and functins f arteries, veins and capillaries Large diagrams t label and clur. Mdels f heart. Obtain a fresh heart frm a legal apprved surce t demnstrate external and internal structures especially thickness f the atrial and ventricular walls, the nature f the valves and crnary bld vessels. Measure pulse rate at wrist. Plan investigatin n effect f exercise n pulse rate. Mdel trs r large diagram t lcate, identify and name the main bld vessels. Biviewers f micrscpe slides f TS artery and vein t see the thickness f walls. Nte the arteries and veins seen previusly when lking at a fresh heart structure. Explain hw structure and functin are related in arteries, veins and capillaries Describe the transfer f materials betweencapillaries and tissue fluid

20 7.2.3 Bld Identify red and white bld cells as seen under the light micrscpe n prepared slides, and in diagrams and phtmicrgraphs List the cmpnents f bld as red bld cells, white bld cells, platelets and plasma Use f phtmicrgraphs f bld smears t identify bld cells. Vide Use f biviewers r micrscpes and prepared slides. Safety n use f bld in class. State the functins f bld cmpnents. Describe the immune system in terms f antibdy prductin, tissue rejectin and phagcytsis Pster wrk. Vide. Link with vaccinatin in discussin. Describe the functin f the lymphatic system in circulatin f bdy fluids, and the prductin f lymphcytes Describe the prcess f cltting (fibringen t fibrin nly)

21 8. Respiratin Define respiratin as the chemical reactins that break dwn nutrient mlecules in living cells t release energy State the uses f energy in the bdy f humans: Paper cards fr wrds and symbls t arrange in rder fr the equatins. Pster wrk fr listing all f the uses. muscle cntractin, prtein synthesis, cell divisin, active transprt, grwth, the passage f nerve impulses and the maintenance f a cnstant bdy temperature 8.1 Aerbic respiratin Define aerbic respiratin as the release f a relatively large amunt f energy in cells by the breakdwn f fd substances in the presence f xygen State the wrd equatin fr aerbic respiratin State the equatin fr aerbic respiratin using symbls (C6H12O6 + 6O2 6CO2 + 6H2O)

22 8.2 Anaerbic respiratin Define anaerbic respiratin State the wrd equatin fr anaerbic respiratin in muscles during hard exercise (glucse lactic acid) and the micrrganism yeast (glucse alchl + carbn dixide) Describe the rle f anaerbic respiratin in yeast during brewing and bread-making Cmpare aerbic respiratin and anaerbic respiratin in terms f relative amunts f energy released State the balanced equatin fr anaerbic respiratin in muscles (C6H12O6 2C3H6O3) and the micrrganism yeast (C6H12O6 2C2H5OH + 2CO2), using symbls Prepare culture f yeast in sugar slutin. Observe prductin f CO 2 by bubbling int water. Research bread making and flur imprvers. Investigatin t shw cmparative rising f dugh in iled measuring cylinders in warm water bath. Research brewing f wines and beer. Visit industrial sites fr bakery f vineyard. Describe the effect f lactic acid in muscles during exercise (include xygen debt in utline nly).

23 8.3 Gas exchange List the features f gas exchange surfaces in animals Identify n diagrams and name the larynx, trachea, brnchi, brnchiles, alveli and assciated capillaries State the differences in cmpsitin between inspired and expired air Use lime water as a test fr carbn dixide t investigate the differences in cmpsitin between inspired and expired air Investigate and describe the effects f physical activity n rate and depth f breathing Pssible t btain a set f lungs frm legal surce t pump air int lungs [ car tyre pump] t bserve rise and fall. Mdel trs r large diagram fr structure. Demnstrate indicatr clur changes limewater and hydrgencarbnate. Cmpare inhaled and exhaled air using simple apparatus [ huff- puff apparatus muthpiece with tubing]. Describe the rle f the ribs, the internal and external intercstal muscles and the diaphragm in prducing vlume and pressure changes leading t the ventilatin f the lungs Use f bell jar apparatus with rubber sheet fr diaphragm. Rib mdel t illustrate muscles. Explain the rle f mucus and cilia in prtecting the gas exchange system frm pathgens and particles Explain the link between physical activity and rate and depth f breathing in terms f changes in the rate at which tissues respire and therefre f carbn dixide cncentratin and ph in tissues and in the bld Use f spirmeter and recrding r use large diagram t shw apparatus. Vital capacity use inverted plastic cntainer f bell jar with measurements t determine vital capacity

24 9. Excretin in humans Define excretin. Substances shuld include carbn dixide, urea and salts Describe the functin f the kidney in terms f the remval f urea and excess water and the reabsrptin f glucse and sme salts (details f kidney structure and nephrn are nt required) State the relative psitins f ureters, bladder and urethra in the bdy State that urea is frmed in the liver frm excess amin acids State that alchl, drugs and hrmnes are brken dwn in the liver Outline the structure f a kidney and utlinethe structure and functining f a kidney tubule including: Demnstratin using the trs r use f large diagrams Vide fr demnstratin Pster wrk Large diagrams f kidney and kidney tubule t label fr functins. Revise transprt acrss membranes and filtratin. Dissectin f animal kidney t shw difference between crtex and medulla. [ t btain frm lcal butcher r abattir in fat / suet t preserve the ureter and bld vessels] Diagrams t cmpare cmpsitin f filtrate t urine alng the length f kidney tubule. Vide. rle f renal capsule in filtratin frm bld f water, glucse, urea and salts rle f tubule in reabsrptin f glucse, mst f the water and sme salts back int the bld, leading t cncentratin f urea in the urine as well as lss f excess water and salts Explain dialysis in terms f maintenance f glucse and prtein cncentratin in bld and diffusin f urea frm bld t dialysis Use f visking tubing t demnstrate diffusin. Samples f clured water cntaining sugar, prtein use diluted cld tea t

25 fluid Discuss the applicatin f dialysis in kidney machines prvide clur] Simple fd test r clinistix t identify samples. Discuss the advantages and disadvantages f kidney transplants, cmpared with dialysis

26 10. Crdinatin and respnse 10.1 Nervus cntrl in humans Describe the human nervus system in terms f the central nervus system (brain and spinal crd as areas f crdinatin) and the peripheral nervus system which tgether serve t crdinate and regulate bdy functins Identify mtr (effectr), relay (cnnectr) and sensry neurnes frm diagrams Describe a simple reflex arc in terms f sensry, relay and mtr neurnes, and a reflex actin as a means f autmatically and rapidly integrating and crdinating stimuli with respnses State that muscles and glands can act as effectrs Describe the actin f antagnistic muscles t include the biceps and triceps at the elbw jint Define sense rgans as grups f receptr cells respnding t specific stimuli: light, sund, tuch, temperature and chemicals Describe the structure and functin f the eye, including accmmdatin and pupil reflex. Pster wrk. Vides. Simple examples f vluntary and invluntary actins linking the cntrl with the actin f muscles and glands. List the different steps in a learning activity t catch a ball. Use large diagrams and mdels f brain t demnstrate different parts f the brain and t shw the prtectin f the brain by the skull. Diagrams t label f spinal crd t shw grey matter and white matter. Demnstratins f size f neurnes biviewers r phtmicrgraphs. Demnstratins f reflex actins pupil / iris reflex, blinking etc. Plan an investigatin t find speed f reactin drpping the ruler r nline tests. Diagrams r mdels f muscles and bnes f frearm. Bnes n skeletn t identify types f jints and mvement. Demnstratins f sense f temperature and tuch by individuals. Paper clip tip tuch investigatin t shw sensitivity. Temperature receptin f differences nt actual temperatures cmpare with thermmeters. Mdel eye. Vides. Demnstratin with lenses t frm a sharp clear image.

27 Diagrams f rds and cnes t appreciate size and functin. Opprtunity t check clur visin with test charts f bks. Distinguish between vluntary and invluntary actins Distinguish between rds and cnes, in terms f functin and distributin 10.2 Hrmnes Define a hrmne as a chemical substance, prduced by a gland, carried by the bld, which alters the activity f ne r mre specific target rgans and is then destryed by the liver State the rle f the hrmne adrenaline in chemical cntrl f metablic activity, including increasing the bld glucse cncentratin and pulse rate Give examples f situatins in which adrenaline secretin increases Cmpare nervus and hrmnal cntrl systems. Large diagrams and trs t lcate endcrine glands. Paper based cards dmines t match hrmnes with glands and cntrl actins. Discussin f the adrenaline cntrl and when this hrmne maybe secreted. Vide and web sites fr industrial uses. If cmbined with site visits t farms r labratries r factries. Discuss the use f hrmnes in fd prductin

28 10.3 Trpic respnses Define and investigate getrpism (as a respnse in which a plant grws twards r away frm gravity) and phttrpism (as a respnse in which a plant grws twards r away frm the directin frm which light is cming). Explain the chemical cntrl f plant grwth by auxins including getrpism and phttrpism in terms f auxins regulating differential grwth, and the effects f synthetic plant hrmnes used as weedkillers Grw bean r cereal seedlings in gas jars t keep sht r cleptiles and rt systems straight. Turn nt side and pin nt bard t shw psitive getrpism f rts and negative getrpism f cleptiles. Pin sme germinating beans t clinstat r keep rtating grwth f seedlings. Grw cress / cabbage seedlings in pt t shw respnse t light frm ne side. If pssible use different grwth bxes with clured filters t experiment with differing wavelengths. Observe use f weedkillers by lking at parks / glf curses where areas have been sprayed. Grw seedlings f brad leaved plants and grasses tgether in trays and spray with weedkiller t shw differential killing f plants [ takes several weeks] Hmestasis Define hmestasis. Identify, n a diagram f the skin: hairs, sweat glands, temperature receptrs, bld vessels and fatty tissue Describe the maintenance f a cnstant bdy temperature in humans in terms f insulatin and the rle f temperature receptrs in the skin, sweating, shivering, vasdilatin and vascnstrictin f arteriles supplying skin surface capillaries and the crdinating rle f the brain. Vide. Magnifying glass t bserve wn skin. Observe the sweat pres n the finger tips and unique arrangement f ridges link with fingerprinting. Use dry cbalt chlride papers n sweaty palms t shw clur change. Nte the distributin f hairs n frnt and back f hands and n arms. Observe phtmicrgraphs. Use varius glass cntainers and cverings t investigate cling f ht water - effect f size [ mther v baby]; stature ; clthing layers v wet cvering; link with surface area vlume ratis. Chill factrs with varying wind speed.

29 Explain the cncept f cntrl by negative feedback Describe the cntrl f the glucse cntent f the bld by the liver, and by insulin and glucagn frm the pancreas Grup f test tubes t demnstrate the herding instinct f animals. Discussin f diabetes Drugs Define a drug as any substance taken int the bdy that mdifies r affects chemical reactins in the bdy Describe the medicinal use f antibitics fr the treatment f bacterial infectin Describe the effects f the abuse f herin: a pwerful depressant, prblems f addictin, severe withdrawal symptms and assciated prblems such as crime and infectin e.g. HIV/AIDS Describe the effects f excessive cnsumptin f alchl: reduced self-cntrl, depressant, effect n reactin times, damage t liver and scial implicatins Describe the effects f tbacc smke and its majr txic cmpnents (tar, nictine, carbn mnxide, smke particles) n the gas exchange System. Investigate the effect f caffeine n heart rate f micrscpic invertebrate aquatic animal eg Daphnia. Effects f antibitic disks n grwth f bacteria n agar plate [ use nly recmmended permitted bacterial strains frm reliable surces] r phtgraphs. Pster wrk based n vides. Alchl intake measured in units and link with vehicle driving and rad accidents. Vides t warn f the dangers f smking. Smking in fume cupbard f cigarette attached t water pump and cllect tar n cttn wl. Explain why antibitics kill bacteria but nt viruses

30 Sectin III: Develpment f the rganism and the cntinuity f life. (25% teaching time) Syllabus reference 1. Reprductin 1.1 Asexual reprductin Define asexual reprductin as the prcess resulting in the prductin f genetically identical ffspring frm ne parent Describe asexual reprductin in bacteria spre prductin in fungi and tuber frmatin in Ptates. Observe varius plant specimens, t include the ptat and ther tubers, runners. T bserve grwth f mulds and spre prductin can use blue-vein cheese if micrscpes are available. Discuss clning. Discuss the advantages and disadvantages t a species f asexual reprductin 1.2 Sexual reprductin Define sexual reprductin as the prcess invlving the fusin f haplid nuclei t frm a diplid zygte and the prductin f genetically dissimilar ffspring. Discuss the advantages and disadvantages t a species f sexual reprductin

31 1.2.1 Sexual reprductin in plants Identify and draw, using a hand lens if necessary, the sepals, petals, stamens, anthers, carpels, varies and stigmas f ne, lcally available, named, insect-pllinated, dictylednus flwer, and examine the pllen grains under a light micrscpe r in phtmicrgraphs Observe large, insect pllinated flwers frm a lcal surce. Use a hand lens t see detail f stigma, nectary, etc.. State the functins f the sepals, petals,anthers, stigmas and varies Define pllinatin as the transfer f pllen grains frm the male part f the plant (anther f stamen) t the female part f the plant (stigma) Name the agents f pllinatin Cmpare the different structural adaptatins f insect-pllinated and wind-pllinated flwers Describe the grwth f the pllen tube and its entry int the vule fllwed by fertilisatin (prductin f endsperm and details f develpment are nt required) Investigate and describe the structure f a nn-endspermic seed in terms f the embry (radicle, plumule and ctyledns) and testa, prtected by the fruit Outline the frmatin f a seed. State that seed and fruit dispersal by wind and by animals prvides Germinate pllen grains t view pllen tubes and bserving the micrscpic extensin [in a shrt time] in suitable medium n glass slides. Large diagrams psters t shw the rute taken by pllen tubes. Psters / charts t fllw the fate f different parts f the flwer when fertilisatin has taken place. Use a hand lens t identify and describe the anthers and stigmas f ne, lcally available, named, wind-pllinated flwer. Examine the pllen grains under a light micrscpe r in phtmicrgraphs. Candidates shuld expect t apply their understanding f the flwers they have studied t unfamiliar flwers.

32 a means f clnising new areas Describe, using named examples, seed and fruit dispersal by wind and by animals by wind and by animals. Distinguish between self-pllinatin and crsspllinatin Discuss the implicatins t a species f self pllinatin and crsspllinatin Observe large saked seeds eg beans t bserve ctyledns, plumule and radicle and grw sme seeds t shw bth hypgeal and epigeal types f germinatin.. Observe a range f fruits and discuss dispersal means. n Sexual reprductin in humans Identify n diagrams f the male reprductive system, the testes, scrtum, sperm ducts, prstate gland, urethra and penis, and state the functins f these parts Identify n diagrams f the female reprductive system, the varies, viducts, uterus, cervix and vagina, and state the functins f these parts Describe the menstrual cycle in terms f changes in the uterus and varies Outline sexual intercurse and describe fertilisatin. Outline early develpment f the zygte. Use f mdels r large diagrams.. vide Cnstruct charts t align events in the basic 28 day cycle - the hrmnes and changes in vary and thickening f the uterus wall prir t vulatin. Outline the develpment f the fetus Describe the functin f the placenta andumbilical crd. Describe the ante-natal care f pregnant wmen including special Mdels and cmpletin f fact sheets n fetal develpment

33 dietary needs and maintaining gd health Outline the prcesses invlved in labur and birth Vide Cmpare male and female gametes in terms f size, numbers and mbility Explain the rle f hrmnes in cntrlling the menstrual cycle (including FSH, LH, prgesterne and estrgen) Indicate the functins f the amnitic sac and amnitic fluid Describe the advantages and disadvantages f breast-feeding cmpared with bttle-feeding using frmula milk Cmparisn f different frmula milk available.

34 1.3 Sex hrmnes Describe the rles f teststerne and estrgen in the develpment and regulatin f secndary sexual characteristics at puberty. Describe the sites f prductin and the rles f estrgen and prgesterne in the menstrual cycle and in pregnancy (crss reference 1.2.2) 1.4 Methds f birth cntrl Outline the fllwing methds f birth cntrl: Pssible t arrange visit by lcal health adviser. natural (abstinence, rhythm methd) chemical (cntraceptive pill, spermicide) mechanical (cndm, diaphragm, femidm, IUD) surgical (vasectmy, female sterilisatin) Outline artificial inseminatin and the use f hrmnes in fertility drugs, and discuss their scial implicatins

35 1.5 Sexually transmissible diseases Describe the symptms, signs, effects and treatment f gnrrhea Describe the methds f transmissin f human immundeficiency virus (HIV), and the ways in which HIV/AIDS can be prevented frm spreading. Web sites fr data such as Wrld Health Organisatin. Outline hw HIV affects the immune system in a persn with HIV/AIDS 2. Grwth and develpment Define grwth in terms f a permanent increase in size and dry mass by an increase in cell number r cell size r bth Define develpment in terms f increase in cmplexity Investigate and state the envirnmental cnditins that affect germinatin f seeds: requirement fr water and xygen, suitable temperature Measuring grwth f plants eg increase in height with time and determine dry mass by drying in the sun r in an ven t cnstant mass. Observe examples f seed germinatin using different seeds. Germinate seeds in shallw trays r petri dishes, in different places differing in temperature. Germinate seeds in vacuum flasks with thermmeters t demnstrate rise in temperature. Seal seeds under il in water t test germinatin with suitable cntrls t shw need fr xygen / air.

36 3. Inheritance Define inheritance. 3.1 Chrmsmes Define the terms:chrmsme; gene as a length f DNA and cdes fr a specific prtein. allele as any f tw r mre alternative frms f a gene haplid nucleus as a nucleus cntaining a single set f unpaired chrmsmes (e.g. sperm and egg) diplid nucleus as a nucleus cntaining tw sets f chrmsmes (e.g. in bdy cells) Describe the inheritance f sex in humans (XX and XY chrmsmes) Build paper mdels f DNA and chrmsmes. Vide n the discvery f DNA. Lk at web sites, diagrams f the Human genme prject. Lk at diagrams f chrmsmes. T bserve images f human chrmsmes - karytypes. Identify the sex chrmsmes and discuss the genes lcated n these chrmsmes with the human genme prject details.

37 3.2 Mitsis Define mitsis as nuclear divisin giving rise t genetically identical cells in which the chrmsme number is maintained by the exact duplicatin f chrmsmes (details f stages are nt required) State the rle f mitsis in grwth, repair f damaged tissues, replacement f wrn ut cells and asexual reprductin Vide r link t website t shw this prcess f cell divisin animated. Observe phtmicrgraphs. Recgnise the sequence f stages in cell cycle and where DNA is cpied. Use f clured drinking straws t represent chrmsmes and chrmatids. Link with clning identical genetic material. 3.3 Meisis Define meisis as reductin divisin in which the chrmsme number is halved frm diplid t haplid (details f stages are nt required) State that gametes are the result f meisis State that meisis results in genetic variatin s the cells prduced are nt all genetically identical Pster wrk t shw meisis where this takes place. Use f clured drinking straws t represent chrmsmes pairing befre meisis. Vide t shw this type f divisin. Discuss haplid and diplid status and genetic variatin.

38 3.4 Mnhybrid inheritance Define the terms: gentype as genetic makeup f an rganism in terms f the alleles present (e.g. Tt r GG) phentype as the physical r ther features f an rganism due t bth its gentype and its envirnment (e.g. tall plant r green seed) Pster r bard wrk n inheritance f ne characteristic eg seed clur. Purchase seeds frm specific crsses t germinate eg Tbacc seeds, upn germinatin have ctyledns with and withut chlrphyll in 3:1 rati. hmzygus as having tw identical alleles f a particular gene (e.g. TT r gg). Tw identical hmzygus individuals that breed tgether will be pure-breeding heterzygus as having tw different alleles f a particular gene (e.g. Tt r Gg), nt pure-breeding dminant as an allele that is expressed if it is present (e.g. T r G) recessive as an allele that is nly expressed when there is n dminant allele f the gene present (e.g. t r g) Use Punnett squares t fllw inheritance. Discussin f back crssing and test crssing. Discuss hw it is easier t experiment with plants. Explain cnventin f circling gametes in inheritance diagrams. Calculate and predict the results f mnhybrid crsses invlving 1 : 1 and 3 : 1 ratis. Pster wrk and bard wrk t explain the inheritance f alleles which shw cdminance. Explain cdminance by reference t the inheritance f ABO bld grups, phentypes, A, B, AB and O bld grups and gentypes.

39 3.5 Variatin State that cntinuus variatin is influenced by genes and envirnment, resulting in a range f phentypes between tw extremes, e.g. height in humans State that discntinuus variatin is caused by genes alne and results in a limited number f distinct phentypes with n intermediates e.g. A, B, AB and O bld grups in humans Define mutatin as a change in a gene r chrmsme Describe mutatin as a surce f variatin, as shwn by Dwn s syndrme T shw cntinuus variatin in plants as well as humans, measure size f fruits r seeds, number f beans t be picked up in ne hand, height, hand span, etc. Wrk ut the frequency f large data sets and plt histgrams. T discuss inheritance f different characteristics in plants as well as humans t shw discntinuus variatin.eg tasters v nn tasters, lbed ears v attached ears. Observe human karytype t identify trismy [chrmsme 21] with Dwns Syndrme and t lk at the incidence thrugh data n web sites. Pster wrk n inheritance f sickle cell anaemia and incidence in the wrld. Outline the effects f inising radiatin and chemicals n the rate f mutatin Describe sickle cell anaemia, and explain its incidence in relatin t that f malaria

40 3.6 Selectin Describe the rle f artificial selectin in the prductin f varieties f animals and plants with increased ecnmic imprtance Define natural selectin as the greater chance f passing n f genes by the best adapted rganisms Opprtunity t visit lcal museum t bserve evlutin galleries. Diagram and discussin f sme plant and animal examples f artificial selectin eg bread wheat. Describe variatin and state that cmpetitin leads t differential survival f, and reprductin by, thse rganisms best fitted t the envirnment Assess the imprtance f natural selectin as a pssible mechanism fr evlutin Describe the develpment f strains f antibitic resistant bacteria as an example f natural selectin 3.7 Genetic Engineering Define genetic engineering as taking a gene frm ne species and putting it int anther species Pster wrk t shw stages in prcess in the develpment f humilin. Vide. Discuss examples f genetically engineered rganisms in many crp plants and the advantages f these. Explain why, and utline hw, human insulin genes were put int bacteria using genetic engineering

41 Sectin IV: Relatinships f rganisms with ne anther and with their envirnment. (20% teaching time) Syllabus reference 1. Energy flw State that the Sun is the principal surce f energy input t bilgical systems Describe the nn-cyclical nature f energy flw 2. Fd chains and fd webs (emphasis n examples ccurring lcally) Define the terms: fd chain as a chart shwing the flw f energy (fd) frm ne rganism t the next beginning with a prducer (e.g. mahgany tree caterpillar sng bird hawk) Opprtunity t g int a natural area lcally and identify the feeding relatinships f the rganisms which can be seen. If this is nt pssible nt then bring int the class rm - living plants eg nettles r leaf litter and identify the species and the feeding relatinships. Watch a vide and build up fd chains and fd webs, perhaps f a different ecsystem. fd web as a netwrk f intercnnected fd chains shwing the energy flw thrugh part f an ecsystem prducer as an rganism that makes its wn rganic nutrients, usually using energy frm sunlight, thrugh phtsynthesis cnsumer as an rganism that gets its energy by feeding n ther rganisms herbivre as an animal that gets its energy by eating plants carnivre as an animal that gets its energy by eating ther animals Visit a farm centre, library r a field centre t find ut mre examples. Talk abut energy and discuss units. Use a simple calrimeter t find energy cntent f seeds r fd items. When searching fr living specimens in leaf litter r n plants fr animals, identify [ recall use f keys t identify rganisms] and assign t trphic feeding levels. These can be weighed [fresh weight] r cunted t draw the trphic blcks in pyramid diagrams.

42 decmpser as an rganism that gets its energy frm dead r waste rganic matter ecsystem as a unit cntaining all f the rganisms and their envirnment, interacting tgether, in a given area e.g. decmpsing lg r a lake trphic level as the psitin f an rganism in a fd chain, fd web r pyramid f bimass, numbers r energy Describe energy lsses between trphic levels Draw, describe and interpret pyramids f bimass and numbers Have data available if unable t d this and build up diagrams. Cnsult tables fr dry bimass t preserve the specimens and return t the envirnment. Explain why fd chains usually have fewer than five trphic levels Explain why there is an increased efficiency in supplying green plants as human fd and that there is a relative inefficiency, in terms f energy lss, in feeding crp plants t animals

43 3. Nutrient cycles Describe the carbn and the water cycles Vides. Diagrams. Describe the nitrgen cycle in terms f: the rle f micrrganisms in prviding usable nitrgencntaining substances by decmpsitin and by nitrgen fixatin in rts the absrptin f these substances by plants and their cnversin t prtein fllwed by passage thrugh fd chains, death, decay nitrificatin and denitrificatin and the return f nitrgen t the sil r the atmsphere (names f individual bacteria are nt required) Observe plant rts f the pea and bean family. [legumes ] Lk fr the pink clratin as these are actively fixing nitrgen [ symbisis / mutualism explain term] Use f biviewers, micrscpes r phtmicrgraphs t bserve sectins thrugh ndules. Discuss the effects f the cmbustin f fssil fuels and the cutting dwn f frests n the xygen and carbn dixide cncentratins in the atmsphere

44 4. Ppulatin size Define ppulatin as a grup f rganisms f ne species, living in the same area at the same time State the factrs affecting the rate f ppulatin grwth fr a ppulatin f an rganism (limited t fd supply, predatin and disease), and describe their imprtance Identify the lag, expnential (lg), statinary and death phases in the sigmid ppulatin grwth curve fr a ppulatin grwing in an envirnment with limited resurces Describe the increase in human ppulatin size and its scial implicatins Interpret graphs and diagrams f human ppulatin grwth Grw a yeast culture in a flask with lw sugar cntent. Start with lw density f cells and bserve. Data handling f cunt numbers r test turbidity f yeast culture. Pster wrk / large diagrams f grwth curve perhaps handling data frm a published surce. Interpretatin f human ppulatin pyramids and diagrams available frm web sites r published data in jurnals. Wrk with published data t find areas where human ppulatins are highest and lwest and discuss the reasns fr this pattern f distributin. Explain the factrs that lead t the lag phase, expnential (lg) phase and statinary phase in the sigmid curve f ppulatin grwth making reference, where apprpriate, t the rle f limiting factrs

45 5. Human influences n the ecsystem Outline the effects f humans n ecsystems, with emphasis n examples f internatinal imprtance (trpical rain frests, ceans and imprtant rivers) 5.1 Agriculture List the undesirable effects f defrestatin (t include extinctin, lss f sil, flding, carbn dixide build up) Describe the undesirable effects f veruse f fertilisers (t include eutrphicatin f lakes and rivers) 5.2 Pllutin Describe the undesirable effects f pllutin t include: water pllutin by sewage and chemical waste air pllutin by sulfur dixide air pllutin by greenhuse gases (carbn dixide and methane) cntributing t glbal warming pllutin due t pesticides and herbicides Opprtunity t visit t sample lcal streams r rivers t find diversity f invertebrates t estimate Bilgical xygen demand and determine level f pllutin. Measure xygen cntent f water frm pnds using methylene blue tests r xygen meters if available. Observe safety at all times.

46 pllutin due t nuclear fall-ut Discuss the effects f nn-bidegradable plastics in the envirnment Pssible t shw bleaching effect f sulfur dixide in a fume cupbard n paper r msses. [effective at lw cncentratins] Discuss the causes and effects n the envirnment f acid rain, and the measures that might be taken t reduce its incidence Explain hw increases in greenhuse gases (carbn dixide and methane) are thught t cause glbal warming 5.3 Cnservatin Describe the need fr cnservatin f: species and their habitats natural resurces (limited t water and nn-renewable materials including fssil fuels) Explain hw limited and nn-renewable resurces can be recycled (including recycling f paper and treatment f sewage t make the water that it cntains safe t return t the envirnment r fr human use) Opprtunity t visit cnservatin sites r t watch vides r TV prgrams. Put up lcal nesting bxes fr birds. Keep an area f garden fr wildlife. Plant insect lving shrubs and flwering plants eg Buddleja. Opprtunity t visit sewage treatment plant and t refer t a simple flw chart t understand the prcesses. T understand lcal r cuntry wide legislatin fr sewage treatment discussin. Opprtunity t visit lcal industrial prcessing sites invlved with re-cycling f paper, aluminium r glass.