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Ocr Biology Higher, B1,B2,B3 exam 19th may Core science revision AQA GCSE Science Unit 1 ***OFFICIAL THREAD*** Reflex actions—BIOLOGY Neurones, CNS, PNS Help! I have included the comments from the examiners reports. “Tom made a big difference to my results and my Biology, and I hope he has the chance to do the same for many more - Lukas (Eton College)” Current A level Biology teacher 23 years of teaching just A level Biology Lots of experience with OCR A, AQA, Eduqas, CIE … take a further 5 and measure them but leave the tip on. (a) (i) On Fig. Preservation is keeping species and habitats as they are now and keeping things 'natural' with minimal human activity. The chemical energy stored in plant biomass after respiratory losses (R) to the environment have been taken into account. 1.2. origin solvent front Y X leucine Volcanos releasing carbon into the atmosphere from the mantle. plant produces abscisic acid and causes stomatal closure and reduced gaseous exchange, glucose - (ATP to ADP) > glucose phosphate - (ATP to ADP) > hexose bisphosphate -> 2 triose phosphate - (4ADP make 4ATP and 2NAD are reduced) > 2 pyruvate, transports pyruvate into the mitochondria, pyruvate - (2NAD become reduced, CO2 released) > acetyl CoA, what is produced per glucose in link reaction, what is produced per glucose in krebs cycle, 6 reduced NAD, 2 reduced FAD, 4 CO2 and 2 ATP, how much ATP is made during oxidative phosphorylation, 28, which means overall 32 is made as 2 are made in glycolysis and 2 in Krebs, why is the net gain of ATP for respiration not always 32, - some ATP is used to actively transport pyruvate into the mitochondrial matrix, pyruvate - (CO2 is released, catalysed by pyruvate decarboxylase) > ethanal - (reduced NAD makes NAD, catalysed by ethanal dehydrogenase) > ethanol, pyruvate - (reduced NAD makes NAD, catalysed by lactate dehydrogenase) > lactate, converted to pyruvate, glucose or glycogen, where are hydrogen ions pumped from and to through ATP synthase in oxidative phosphorylation, from the matrix, through the electron transport carriers into the intermembrane space, then through ATP synthase into the matrix again to form water, can differentiate into any cell type, embryo stem cells, stem cells that can become a limited number of types of tissues and cells in the body, adult stem cells. OCR A Level Biology Past Papers We have put together a comprehensive list of past papers for all of the OCR A-Level Biology exams. Candidates answer on the Question Paper OCR Supplied Materials: † Insert (inserted) Other Materials Required: ... neurones of different animal taxa. Biology A A Level. AS OCR A Level Chemistry Student book 2. In an expanding triple nucleotide increases at meiosis again and again from generation to generation. OCR A Level Biology Student book 2. 1.1 shows the structure of the amino acid leucine. Without grazing causing deflected succession, the environment would revert to a climax community of oak woodland. to the aleurone layer in the endosperm region to produce amylase, - detection of changes in the environment, two systems that oppose each others effects, stimulates release of ACTH (adrenocorticotropic hormone), Stimulates adrenal cortex to release glucocorticoids (cortisol) which regulate carbohydrate metabolism, stimulates release of TSH (thyroid-stimulating hormone), Stimulates thyroid gland to produce thyroxine which makes cells more sensitive to adrenaline, sensory input to the cardiovascular centre, longitudinal (causes wave-like contractions) and circular (causes segmentation contractions), made of myocytes and intercalated discs to allow free diffusion of ions between cells, a motor neuron and all the muscle cells it stimulates (it stimulates two or more), actin wrapped in tropomyosin with troponin receptors (binds to actin, tropomyosin and calcium when available), holds thin filaments, marks ends of sarcomere, 1. myosin head attaches to actin filament to create a cross bridge, a 60 amino acid sequence coded for my a homeobox gene which can binds to DNA regulating the transcription of genes, they are a type of transcription factor, 9:3:3:1 when organisms are heterozygous for two traits, characteristics for which there are three or more alleles in the populations gene pool. A Level Biology for OCR A Student Book Answers. But this allows a cell to differentiate. OCR. Mark Scheme. A Level Biology A H420/01 Biological processes Thursday 7 June 2018 – Morning Time allowed: 2 hours 15 minutes You must have: • the Insert (inserted) You may use: • a scientific or graphical calculator • a ruler (cm/mm) *6900816630* OCR is an exempt Charity *H42001* all cells express 'housekeeping' genes so these aren't switched off. Exam questions organised by topic, past papers and mark schemes for the NEW OCR A … 6 Ribulose bisphosphate + 6 CO2 -> 12 glycerate-3-phosphate - (12xATP make 12xADP and 12x reduced NADP make 12xNADP) > 12 triose phosphate (2 of which are the product, the rest are recycled) - (5xATP make 5x ADP) > 6 RuBP, effect of changing light intensity on the products of the Calvin cycle, GP cannot be reduced to TP so GP accumulates and TP and RuBP fall, effect of changing CO2 concentration on the products of the Calvin cycle, RuBP cannot accept it so it accumulates and GP cannot be made therefore TP cannot be made, effect of changing temperature on the Calvin cycle. Agricultural practices improve primary productivity by: Saprobionts convert organic matter like waste and dead organisms into ammonia by extracellular digestion, Atmospheric nitrogen is converted into ammonia by nitrogen fixing bacteria in the soil (Azotobacter) and root nodules (Rhizobium), Ammonia is converted into nitrites (Nitrosomonas) then nitrates (Nitrobacter), Conversion of nitrates into nitrogen gas, needs anaerobic conditions (e.g. This relationship can be described by the following equation: Net production of consumers (e.g. Images were taken from boundless.com. So if you’re revising Cell Division for OCR (A) A-Level Biology, you can find all of the Cell Division questions that have been ever asked by OCR in one single document - useful, no? Past papers, summary notes, factsheets and past exam questions by topic for AQA, CIE, Edexcel, OCR and WJEC Biology AS and A-Levels Ocr a level biology exam questions by topic