Save my exams biology a level notes. DCPIP and methylene blue are redox indicators.

Save my exams biology a level notes Author: Phil Expertise: Biology Content Creator Phil has a BSc in Biochemistry from the University of Birmingham, followed by an MBA from Manchester Business School. the scene at which a dead body is found; Determining the time of Author: Naomi Holyoak Expertise: Biology Naomi graduated from the University of Oxford with a degree in Biological Sciences. The distribution of a species describes how it is spread throughout the ecosystem. During those years she taught three different GCSE exam boards and two A-Level exam boards, gaining a Author: Phil Expertise: Biology Content Creator Phil has a BSc in Biochemistry from the University of Birmingham, followed by an MBA from Manchester Business School. Antibodies are globular glycoproteins called immunoglobulins. Save My Exams-Probably the Revision notes on Eukaryotic Cell Structures & Functions for the Cambridge (CIE) A Level Biology syllabus, written by the Biology experts at Save My Exams. Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the Author: Cara Head Expertise: Biology Content Creator Cara graduated from the University of Exeter in 2005 with a degree in Biological Sciences. You can also find resources, memes, and friends on r/alevel. If the grass field is 200 m² in size, then the biomass of the whole field must be RNA nucleotides. If the osmoreceptors detect a decrease in Proteins: Structures & Functions. Preparing a slide using a liquid specimen:. Make sure you learn the three levels of potency of stem cells described above, and what range of cell types these stem cells can differentiate into. Bioinformatics is a field of biology that involves the storage, retrieval, and analysis of data from biological studies; These studies may generate data on DNA sequences, RNA sequences, and protein sequences, as well as on the relationship between genotype and phenotype; High-power computers are required to create databases; The large Meiosis in Animal & Plant Cells. The amount of glucose that gets absorbed into the blood from the products of Our Revision Notes are exam board specific, so you’ll never revise anything you don’t need to. Synaptic transmission. 2. The cut portion is inverted 180° then rejoined to the same Author: Cara Head Expertise: Biology Content Creator Cara graduated from the University of Exeter in 2005 with a degree in Biological Sciences. 2 Levels of Organisation of Cells for the Edexcel International A Level Biology syllabus, written by the Biology experts at Save My Exams. After completing a PGCE (Postgraduate certificate in education) in 2003 she taught high school Biology for over 10 years at various schools across South Africa before returning to Stellenbosch University in Photosynthesis is a series of chemical reactions that occurs in producers such as plants and algae . Amylopectin (70 - 90% of starch) 1,4 glycosidic bonds between α-glucose molecules but also 1,6 glycosidic bonds form between glucose molecules creating a branched molecule. From the outside most cells look almost identical with the same DNA in their nucleus. She has fifteen years of experience teaching the Sciences at KS3 to KS5, and Psychology at A-Level. Electrical impulses cannot ‘jump’ across synapses. Critical to the enzyme's function is the active site where the substrate binds. Passive immunity. You may notice that this process bears a strong resemblance to PCR, but with The B lymphocyte Response B-lymphocytes and the humoral immune response. The neurotransmitters diffuse across the synaptic cleft and temporarily bind with Evolution. 2 kg per square metre). The inside of the axon Author: Lucy Kirkham Expertise: Head of STEM Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels. Summary of the light-dependent stage Reduced NADP is produced when hydrogen ions combine with the carrier molecule NADP using electrons from The location and structure of a nephron. Within each division there are the following stages: prophase, Author: Lucy Kirkham Expertise: Head of STEM Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels. They’re written by teachers and tutors, who specialise in each subject, and are regularly updated to match the latest syllabus. 3 Photosynthesis: Light-Dependent Stage for the Edexcel International A Level Biology syllabus, written by the Biology experts at Save My Exams. Having genetically different offspring can be advantageous for natural selction. HIV avoids being recognised and destroyed by lymphocytes by Osmosis and the partially permeable membrane. All the course specific revision resources you need to ace your A Level exams. The genetic code is universal, meaning that almost every organism uses the same four nitrogenous bases – A, T, C & G. It allows us to make sense of our surroundings and respond to them and to coordinate and regulate body functions. Method. Don’t forget, while still classed as stem cells (as they can divide any number of times), only a limited range of specialised cells can be formed from adult stem cells as they have already partially Recombinant DNA Technology Recombinant DNA. For example, the F8 gene codes for the protein Factor VIII involved in blood clotting; Regulatory genes code for proteins (or various forms of RNA) that control the expression of structural genes Tools designed specifically for the Edexcel A (SNAB) A Level Biology syllabus, to help you ace your exams, including: past papers, revision notes, and exam-style questions, created by our expert team of teachers and examiners Replication of HIV. Start studying; Search. Image showing the structure of the tracheal system of an insect. For example, this can be used to test for prostate cancer:. ATP Synthesis. 3. Microarrays are laboratory tools used to detect the expression of thousands of genes at the same time and to identify the genes present in an organism’s genome. A Level and AS Level Exam Dates 2024; Animal Cells Explained | Definition, Functions & Diagram With Save My Exams, your revision resources are The chain termination method in action. Active transport is the movement of molecules and ions through a cell membrane from a region of lower concentration to a region of higher concentration using energy from respiration. This gene codes for the production of chloride ion channels required for secretion of sweat, mucus and digestive juices Situated above each kidney is a gland known as the adrenal gland. The oxygen diffuses from the alveoli and into Revision notes on 15. Largest part of the brain in humans (accounts for about 80% of the total mass of the brain); Carries out a large variety of functions involved with conscious activities, including:. The most well-known carbohydrate monomer is glucose. Choose your A Level Exam Board. This causes them to have very pale skin, very pale hair and pale blue or pink irises in the eyes Author: Lucy Kirkham Expertise: Head of STEM Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels. 2 kg m⁻² (this means 0. 3. As the person’s immune system has not been activated, there are no memory cells that can produce antibodies in a secondary response. A structural gene codes for a protein that has a function within a cell (e. Before a (parent) cell divides, it needs to copy the DNA contained within it. On average humans use more than 50 kg of ATP in a day but only have a maximum of ~ 200g of ATP in their body at any given time. Inorganic ions occur in solution in the Gene control: oestrogen. Meiosis: Sources of Genetic Variation. Variation exists within a species' population. This is why DNA is the storage molecule and RNA is the Expertise: Biology Lead Lára graduated from Oxford University in Biological Sciences and has now been a science tutor working in the UK for several years. This is so that the two new (daughter) cells produced will both receive the full copies of the parental DNA. biomass) of 0. uk-Another really good website for A-Level specific notes. Problems with the mean occur when there are one or two unusually high (or low) values in the data (outliers) which can make the mean too high (or too low) to reflect any patterns in the dataThe mean is sometimes Gas Exchange Processes. DCPIP and methylene blue are redox indicators. Designed by the teachers at Exam Tip It is a good idea to learn the Krebs cycle in detail. In this investigation, the rate of product formation is used to measure the rate of an enzyme The lac operon Structural genes in prokaryotes can form an operon: a group or a cluster of genes that are controlled by the same promoter; The lac operon found in some bacteria is one of the most well-known of these; The lac operon controls the production of the enzyme lactase (also called β-galactosidase) and two other structural proteins; Lactase breaks down Revision notes for the Edexcel International AS Biology syllabus, written by the Biology experts at Save My Exams. An ion that has a -ve charge is known as an anion. Sensory neurones carry impulses from receptors to the CNS (brain or spinal cord); Relay (intermediate) neurones are found entirely within the CNS and connect sensory and motor neurones; Motor neurones carry impulses from the CNS to effectors (muscles or glands); Each type of neurone Author: Phil Expertise: Biology Content Creator Phil has a BSc in Biochemistry from the University of Birmingham, followed by an MBA from Manchester Business School. After completing a PGCE (Postgraduate certificate in education) in 2003 she taught high school Biology for over 10 years at various schools across South Africa before returning to Stellenbosch University in Examiner Tips and Tricks. An ion is an atom (or sometimes a group of atoms) that has an electrical charge. The capillaries of the glomerulus rejoin to form an efferent Revision notes for the Cambridge O Level Biology syllabus, written by the Biology experts at Save My Exams. 7. This process is known as evolution Author: Emma Archbold Expertise: Biology Prior to working at SME, Emma was a Biology teacher for 5 years. Lára has a particular interest in the area of infectious disease and epidemiology, and enjoys creating original educational materials that develop confidence and facilitate learning. Mean. After completing a PGCE (Postgraduate certificate in education) in 2003 she taught high school Biology for over 10 years at various schools across South Africa before returning to Stellenbosch University in Author: Marlene Expertise: Biology Marlene graduated from Stellenbosch University, South Africa, in 2002 with a degree in Biodiversity and Ecology. Oxygen and carbon dioxide are exchanged in a process of simple diffusion; (passive movement from high to low concentration). You may be asked to name the important molecules in the Krebs cycle like oxaloacetate. Mutations can occur spontaneously (i. Membranes, Proteins, DNA & Gene Expression. If all the offspring of every individual survived to adulthood and reproduced, the population would experience exponential growth. 2 Structure of the Mitochondrion for the OCR A Level Biology syllabus, written by the Biology experts at Save My Exams. Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the Structural and regulatory genes. Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the All the course specific revision resources you need to ace your A Level exams. He has 15 years of teaching and tutoring experience, teaching Biology in schools before becoming director of a growing tuition agency. One method of epigenetic control involves the methylation of DNA; Methyl groups (-CH 3) can be directly added to DNA to change the activity of a gene; DNA methylation commonly involves the direct addition of a methyl group to cytosine bases which can influence gene expression; Methylation of DNA suppresses The effective movement of the human body requires both muscle and an incompressible skeleton. FREE Biology revision notes on The Microscope in Cell Studies. Intrinsic proteins are embedded in the membrane with their arrangement The Universal Genetic Code. A gene mutation is a change in the sequence of base pairs in a DNA molecule that may result in an altered polypeptide; Mutations occur continuously. in agriculture to The different effects of environmental factors on the population growth of African lions in the wild. 1 Common Pathogens & Communicable Diseases for the OCR A Level Biology syllabus, written by the Biology experts at Save My Exams. Zoos. Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the Nucleus. B-lymphocytes (B cells) remain in the bone marrow until they are mature and then spread through the body, concentrating in lymph nodes and the spleen. Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the The structure of a fungus with its hyphae, mycelium and fruiting bodies. Adrenal glands are an example of endocrine glands; Both adrenal glands have the same structure and function, consisting of two main areas: a central medulla and an outer cortex; The cortex produces steroid hormones:. After completing a PGCE (Postgraduate certificate in education) in 2003 she taught high school Biology for over 10 years at various schools across South Africa before returning to Stellenbosch University in Revision notes on 3. Non-carbohydrates such as lipids, lactate and amino acids that have been converted to glucose. Kingdom Plantae. The allele frequencies (within the gene pool) of a population can change over time due to processes such as natural selection. 4 Measuring Species Richness & Species Evenness for the OCR A Level Biology syllabus, written by the Biology experts at Save My Exams. Metabolic pathways are controlled by enzymes in a Method. Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the Author: Phil Expertise: Biology Content Creator Phil has a BSc in Biochemistry from the University of Birmingham, followed by an MBA from Manchester Business School. Antibodies are not produced by the infected person. . enzymes, membrane carriers, hormones etc. These dyes can be added to a Non-reversible inhibitors. The oxygen dissociation curve shows the rate at which oxygen associates, and also dissociates, with haemoglobin at different partial pressures of oxygen (pO 2). 1 Classification of Species for the OCR A Level Biology syllabus, written by the Biology experts at Save My Exams. With Save My Exams, Assisted Reproduction. When the allele frequencies of a population change sufficiently over time, the characteristics of the species will also change. A mean value is what is usually meant when the term “average” is used in biology; Mean = sum of all measurements ÷ number of measurements. This means that some individuals within the population possess different phenotypes (due to genetic variation in the alleles they possess; remember, members of the same species will have the The primary and secondary response to the same antigen. s-cool -A-Level specific, good explanations. Nuclear pores are important channels for allowing mRNA and ribosomes to travel Membranes formed from phospholipid bilayers help to compartmentalise different regions of the cell. A large analysis of many studies on vitamin C and heart disease was carried out in 2016 . This process of protein synthesis occurs in two stages:. Humans with albinism lack the pigment melanin in their skin, hair and eyes. the living factors) and the abiotic conditions (i. Note that diffusion can also happen within a cellular compartment; the presence of a membrane is not essential; It can be defined as the net movement of a substance from a region of its higher concentration to a region of its lower concentration. The light-independent stage, which takes place in the stroma. Polysaccharides are insoluble so have less influence on the process of osmosis; Disaccharides and polysaccharides are formed when two hydroxyl (OH) groups on different monosaccharides Double fertilisation. Net movement refers to the overall Author: Lucy Kirkham Expertise: Head of STEM Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels. Business. The proteins can either be intrinsic (or integral) or extrinsic (peripheral). Pathology: comparison between healthy cells and diseased cells to find the characteristics of the disease Biotechnology (e. The phospholipid bilayers that make up cell membranes also contain proteins. Small populations are prone to inbreeding and inbreeding depression. the non-living factors) change over time. The branches result in many terminal glucose molecules that can be Required Practical: Investigating the Effect on the Rate of Respiration. Add a few drops of the sample to the slide using a pipette; Cover the liquid/smear with a coverslip and gently press down to remove air bubbles; Wear gloves to ensure there is no cross-contamination of foreign cells; Methods of preparing a microscope slide using a solid specimen:. Inorganic ions play an important role in many essential cellular processes. These changes can become so great that a new species forms. Vision; Hearing; Speech; Thinking; Memory; Consists of five lobes; Divided into two halves, known as the cerebral hemispheres. It enters the helper T cells by attaching to a receptor molecule on the host cell membrane; The capsid enters the helper T cell and releases the RNA it contains; The viral RNA is used as a Required Practical: Measuring Enzyme Activity. ATP is formed when ADP is combined with an Author: Lucy Kirkham Expertise: Head of STEM Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels. This line is known as the solvent front; The distance between the origin line Examiner Tips and Tricks. After pollination has occurred, the pollen grain begins to 'grow' or 'germinate' and a pollen tube grows from the pollen grain down the style to the ovary of the plant; As the pollen tube grows towards the ovary, two haploid male nuclei move down the tube These are known as the pollen tube nucleus and the generative nucleus; At some point, as it Author: Lucy Kirkham Expertise: Head of STEM Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels. for no reason) during DNA replication; The probability of a mutation occurring can increase with the presence of certain factors known as mutagens, e. Ecosystems are dynamic, meaning that they are constantly changing; Sometimes, ecosystems change from being very simple to being relatively complex. The process is called so because in each new A stem cell is a cell that can divide (by mitosis) an unlimited number of times; Each new cell (produced when a stem cell divides) has the potential to remain a stem cell or to develop into a specialised cell such as a blood cell or a muscle cell (by a process known as differentiation); This ability of stem cells to differentiate into more specialised cell types is known as potency Bioinformatics. A concentration gradient is created as oxygen is used by respiring tissues allowing more to move in through the spiracles by diffusion. A study that analyses the results of many existing studies is known as a meta-analysis; The 2016 study showed that there was no clear relationship between increased vitamin C intake and a reduced risk of heart disease; The study also suggested that Enzymes as Proteins. ADMIN MOD savemyexams biology 9700 a level notes . Structure of membranes. Very active, flying insects need a more rapid Revision notes on 5. If the dry mass of the grass from 1 m² of a field is found to be 0. Replication of HIV. Every individual within a species population has the potential to reproduce and have offspring which contribute to population growth. Concise resources for the Edexcel International A Level Biology course. Producers are also known as autotrophs; organisms that make their own organic compounds; Photosynthesis converts light energy into chemical energy which is then stored in the biomass of producers; The light energy is used to split strong bonds in water Author: Marlene Expertise: Biology Marlene graduated from Stellenbosch University, South Africa, in 2002 with a degree in Biodiversity and Ecology. Transcription – DNA is transcribed and an mRNA molecule is produced. Join and have fun! _shana. An inorganic ion is an ion that does not contain carbon. Water potential describes the tendency of water to move out of a solution. There are three main types of neurone: sensory, relay and motor. Author: Emma Archbold Expertise: Biology Prior to working at SME, Emma was a Biology teacher for 5 years. Polypeptide or protein molecules can have anywhere from 3 amino acids (Glutathione) to more than 34,000 amino acids (Titan) bonded together in chains Revision notes on 5. A Level Past Papers; O Level Past Papers; AP Past Papers; Join now for free; Log in; Learning hub; About us; Help and support; An example of a substitution mutation. The control of the water potential of body fluids is known as osmoregulation. When the virus enters the bloodstream it infects helper T cells, a type of white blood cell that is normally responsible for activating antibody-producing B cells. Home. The portion of the septum which separates the left and Author: Emma Archbold Expertise: Biology Prior to working at SME, Emma was a Biology teacher for 5 years. Open comment sort Author: Lucy Kirkham Expertise: Head of STEM Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels. If a person is reinfected they would The human heart has four chambers and is separated into two halves by the septum. ). Translation – mRNA (messenger RNA) is Step 1: Rank each set of data (rank 1 being the smallest data figure) Step 2: Find the difference in rank between the two species, D Step 3: Square the difference in rank, D 2 (= 6) Step 4: Substitute the appropriate numbers into the equation (remember n = 10). 16 Calculation of Mitotic Index for the Edexcel International A Level Biology syllabus, written by the Biology experts at Save My Exams. Millions of types of B-lymphocyte cells are produced within us because as they mature the genes coding for antibodies are changed to Diffusion is a type of transport that can occur across a cell membrane. Forming a glycosidic bond: condensation reaction. co. Endangered mammals tend to have small and isolated populations. Possess chloroplasts that Revision notes on 1. Translation. Revision notes on 4. Crossing over. The human nervous system consists of the following: Central nervous system (CNS) – the brain and the spinal cord. Measuring the rate of disappearance of a substrate using amylase. . 5. Investigating catalase activity. The branches result in many terminal glucose molecules that can be It is a place to ask, share, and learn about any A Level subject, exam, or plan. Amylose is one of the two polysaccharides that forms starch, the storage polysaccharide in plants. It has many similarities to mitosis however it has two divisions: meiosis I and meiosis II. The DNA nucleotide base code found within a gene is a three-letter, or triplet, code. There are four levels of structure in proteins, three are related to a single polypeptide chain and the fourth level relates to a protein that has two or more polypeptide chains. Ionising radiation The Process of Active Transport & Co-transport Active transport. 1 The Endocrine System for the CIE A Level Biology syllabus, written by the Biology experts at Save My Exams. All the course specific revision resources you need to ace your A Level Biology exams. When populations are isolated it can AS Biology Revision Notes for AQA, Cambridge (CIE), Edexcel A (SNAB), OCR. The distribution and abundance of a species in an area can be assessed using different practical methods: She has 8 years of classroom experience teaching Key Stage 3 up to A-Level biology, and is currently a tutor and A-Level examiner. It produces gametes in plants and animals that are used in sexual reproduction. Check their AP biology and MCAT tabs for the best resources. Within the Bowman’s capsule of each nephron is a structure known as the glomerulus. Information is sent through the nervous Structure of the HIV virus. It is also worth noting how the In your exam you may be asked to explain why RNA analysis is important with regards to gene expression. There is also a network of blood vessels associated with each nephron:. This can be dangerous as can cause the biological reaction the enzyme is catalysing The Purpose of Semi-Conservative Replication. It may seem strange that ATP is used and also produced during glycolysis. The DNA is copied via a process known as semi-conservative replication (semi = half). Since 2 ATP are used and 4 are produced during the process, there is a net gain of 2 ATP per glucose molecule. biology4alevel - Features notes according to the 2016 syllabus (still really useful). Hydrolysis of glycogen stores. The cell cycle has three phases: interphase. 2. 2 kg, we can say that the grass has a dry mass (i. Carbon dioxide produced by the respiring tissues moves out through the spiracles down a concentration gradient. Each polypeptide chain has a constant region and variable region. Revision notes for the Cambridge (CIE) AS Biology syllabus, written by the Biology experts at Save My Exams. Osmosis is the net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution), through a partially permeable membrane. The cell cycle is the regulated sequence of events that occurs between one cell division and the next. Temperature; Solvent concentration; Temperature. Make sure you learn the four stages of mitosis and what is happening to the DNA molecules (one chromatid contains one DNA molecule) at each stage – learn ‘PMAT’ (prophase, metaphase, anaphase, telophase) to help you remember the order of the stages!After interphase but before the parent cell undergoes mitosis, the human parent cell The oxygen dissociation curve. Another type of indirect ELISA test can be used to test whether a patient has specific antigens in their blood plasma. They are used to investigate the effects of temperature and substrate concentration on the rate of anaerobic respiration in yeast. The DNA of a single gene is cut in two places. Present in all eukaryotic cells (except red blood cells), the nucleus is relatively large and separated from the cytoplasm by a double membrane (the nuclear envelope) which has many pores; Nuclear pores are important channels for Osmoregulation. Biology (9700) Lectures, Notes, Topical Past Papers and Extra Resources are accessible here. The exchange of oxygen and carbon dioxide occurs between the alveoli and the capillaries in the lungs. 5. The hemispheres are joined together by a band A synapse. Zoos can also contribute to the conservation of endangered animal species; Captive breeding programmes can breed individuals of a species so their offspring can be released into the wild; Zoos are an invaluable resource for scientific research. The two top chambers are atria and the bottom two chambers are ventricles. Testing for Distribution & Abundance. Inversion within a gene section. Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the The Two Stages of Photosynthesis. Antibodies: Structure Structure. 1. Normally lymphocytes seek out and destroy pathogens that enter the body, producing antibodies that attach to pathogens and enhancing phagocytic activity. Plants are multicellular eukaryotic organisms. Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the Genes code for mRNA which gets translated into a polypeptide (protein) that affects the phenotype of the organism. Some inhibitors can form covalent bonds with enzymes, inhibiting them permanently. Past Papers WJEC Eduqas A Level Biology-Course Overview. Photosynthesis occurs in two distinct stages: The light-dependent stage, which takes place in the thylakoids. Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the Author: Marlene Expertise: Biology Marlene graduated from Stellenbosch University, South Africa, in 2002 with a degree in Biodiversity and Ecology. Active transport requires carrier proteins (each carrier protein being specific for a particular type of molecule or Transcription. Partial pressure of oxygen refers to the pressure exerted by oxygen within a mixture of gases; it is a measure of oxygen concentration; Haemoglobin is referred to as being Inorganic Ions. 1. Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the Examiner Tips and Tricks. Organisms cannot build up large stores of ATP and it rarely passes through the cell surface membrane. 1 Photosynthesis & Respiration for the OCR A Level Biology syllabus, written by the Biology experts at Save My Exams. Osmoregulation is a key part of homeostasis. A gene is a sequence of nucleotide bases in a DNA molecule that codes for the production of a specific sequence of amino acids, that in turn make up a specific polypeptide (protein). Glucose is the most common monosaccharide and is of central importance to most forms of life. Translation – mRNA (messenger RNA) is Amylose – one of the two polysaccharides that is used to form starch (the storage polysaccharide in plants) Amylopectin (70 - 90% of starch) 1,4 glycosidic bonds between α-glucose molecules but also 1,6 glycosidic bonds form between glucose molecules creating a branched molecule. There are different types of monosaccharide formed from molecules with varying numbers of carbon atom, for example: Author: Lucy Kirkham Expertise: Head of STEM Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels. Natural selection & survival. AQA. g. Passive immunity is acquired without an immune response. Take care when using sharp The Cell Cycle. Peripheral nervous system (PNS) – all of the nerves in the body. Microarrays are used in different ways, e. Author: Lucy Kirkham Expertise: Head of STEM Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels. Inconclusive evidence. Explore our International A Level Author: Lucy Kirkham Expertise: Head of STEM Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels. Stage 2: Depolarisation. This increased fluidity reduces the effectiveness of the cell Author: Lucy Kirkham Expertise: Head of STEM Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels. This type of growth only happens when there are no environmental factors or Author: Lucy Kirkham Expertise: Head of STEM Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels. There are a few exceptions. Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the Blood Glucose Concentration. The The permeability of cell membranes is affected by different factors or conditions, such as:. 6 Evidence of Evolution for the OCR A Level Biology syllabus, written by the Biology experts at Save My Exams. Garlic or onion (Allium cepa) root tips are most commonly used (the bulbs can be encouraged to grow roots by suspending them over water for a week or two); Prepare a boiling tube of 1M hydrochloric acid and place in a water bath at 60 o C for 10 minutes; Remove the tips of the roots (about 1cm) and place in the warmed hydrochloric acid for 5 minutes DNA methylation causes the inactivation of genes. When an electrical impulse arrives at the end of the axon on the presynaptic neurone, chemical messengers called neurotransmitters are released from vesicles at the presynaptic membrane. Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the Revision notes on 5. After completing a PGCE (Postgraduate certificate in education) in 2003 she taught high school Biology for over 10 years at various schools across South Africa before returning to Stellenbosch University in The Nervous System. Four test tubes are prepared that contain the DNA to be sequenced (in the form of a single-stranded template), DNA polymerase, DNA primers, free nucleotides A, C, T, and G, and one of the four types of dideoxynucleotide; either A*, C*, T*, or G* . Primary succession is the process that Author: Lucy Kirkham Expertise: Head of STEM Lucy has been a passionate Maths teacher for over 12 years, teaching maths across the UK and abroad helping to engage, interest and develop confidence in the subject at all levels. Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the Revision notes on 4. Naomi especially enjoys creating resources that enable students to build a solid understanding of subject content, while also connecting their knowledge with biology’s exciting, real-world applications. e. Each glomerulus is supplied with blood by an afferent arteriole (which carries blood from the renal artery). Crossing over She has 8 years of classroom experience teaching Key Stage 3 up to A-Level biology, and is currently a tutor and A-Level examiner. Meiosis has several mechanisms that increase the genetic diversity of gametes produced. Author: Marlene Expertise: Biology Marlene graduated from Stellenbosch University, South Africa, in 2002 with a degree in Biodiversity and Ecology. Antibodies have a quaternary structure (which is represented as Y-shaped), with two ‘heavy’ (long) polypeptide chains bonded by disulfide bonds to two ‘light’ (short) polypeptide chains. Microarrays. After a chromatogram has been obtained the molecules present in the sample mixture can be identified by calculating their retardation factor (R f); In order to calculate R f values, a line must be drawn across the chromatogram to show how far the solvent travelled . Proteins and lipids (the major components in cell membranes) are both affected by temperature; As temperature increases, lipids become more fluid. Each sequence of three bases (in other words each triplet of bases) Natural Selection. An ion that has a +ve charge is known as a cation. He has 15 years of teaching and tutoring The cerebrum. This means the cells must make ATP as and when they need it. Scientists are able to closely study animal’s genetics, behaviours and habitat needs; There are some problems Calculating the R f value. Cystic fibrosis is a genetic disorder of cell membranes caused by a recessive allele of the CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) gene located on chromosome 7 . This term is used to avoid confusion Author: Emma Archbold Expertise: Biology Prior to working at SME, Emma was a Biology teacher for 5 years. To make monosaccharides more suitable for storage they are bonded together to form disaccharides and polysaccharides. The left and right sides of the heart are separated by a wall of muscular tissue, called the septum. Meiosis is a form of nuclear division that results in the production of haploid cells from diploid cells. Molecules, Transport & Health. The nucleus of a cell contains chromatin (a complex of DNA and histone proteins) which is the genetic material of the cell . Enzymes are also globular proteins. 10 Electrocardiograms (ECGs) for the OCR A Level Biology syllabus, written by the Biology experts at Save My Exams. The air in the alveoli contains a high concentration of oxygen. Possess large (and usually permanent) vacuoles that provide structural support Are able to differentiate into specialised cells to form tissues and organs. When the virus enters the bloodstream it infects a certain type of lymphocyte - helper T cells. Inbreeding depression is the reduction in fitness of a population due to breeding between closely related individuals and the resulting increased homozygosity. Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the Expertise: Biology Lead Lára graduated from Oxford University in Biological Sciences and has now been a science tutor working in the UK for several years. Present in all eukaryotic cells, the nucleus is relatively large and separated from the cytoplasm by a double membrane (the nuclear envelope) which has many pores. Plant cells: All have cell walls composed of cellulose. The heart is divided into four chambers. The abundance of a species is the number of individuals of that species. Cell Structure, Reproduction & Questions organised by topic, past papers, model answers, video solutions & revision notes. A redox indicator is a substance that changes colour when it is reduced or oxidised. 6. This process is known as succession; During succession, the biotic conditions (i. Sort by: Best. Enzymes are biological catalysts ‘Biological’ because they function in living systems ‘Catalysts’ because they speed up the rate of chemical reactions without being used up or changed. Some questions in the exam may ask you to explain why the variation in phenotype due to genetics is inherited but the variation in phenotype due to environmental factors is not. The progress of enzyme-catalysed reactions can be investigated by:. It involves the collection and analysis of evidence from a potential crime scene e. Measuring the rate of formation of a product using catalase. At the start ATP is used to make glucose more reactive (it is usually very stable) and to lower the activation energy of the reaction. 4. Working as a Head of Department and then Director of Maths, Lucy has advised schools and academy trusts in both Scotland and the An indirect ELISA test can be used to test whether a patient has antibodies to HIV. Usually occurs during crossing-over in meiosis. The Two Forms of Glucose. Example of an indirect ELISA test: testing for antigens. Glucose has the molecular formula C 6 H 12 O 6. alevelbiology. Mitosis is part of a precisely controlled process known as the cell cycle. 6. Biology if anyone has the pdf of these notes pls send 😭🙏 Share Add a Comment. In mammals, the hormone oestrogen is involved in controlling the oestrus cycle and also in sperm production; Oestrogen is a lipid-soluble molecule and can therefore diffuse through the plasma membrane of cells; It then moves to the nucleus and binds to an oestrogen receptor; These receptors are actually transcription factors that are able Forensics is the use of science in the investigation of criminal activities. Save time with clear, simple summaries that make revision quicker and easier. The components of an RNA nucleotide are: A ribose sugar with a hydroxyl (OH) group at the 2' position; A phosphate group; One of four nitrogenous bases - adenine (A), cytosine(C), guanine(G) or uracil (U); The presence of the 2' hydroxyl group makes RNA more susceptible to hydrolysis. nuclear division (mitosis) cell division (cytokinesis) The length of the cell cycle is very variable depending on environmental Author: Phil Expertise: Biology Content Creator Phil has a BSc in Biochemistry from the University of Birmingham, followed by an MBA from Manchester Business School. 1 Experimental Design for the OCR A Level Biology syllabus, written by the Biology experts at Save My Exams. Look for the 0. There are three ways in which glucose can enter the bloodstream: Absorption in the gut following carbohydrate digestion. 05 probability level with n = 10 The nucleus of a cell contains chromatin (a complex of DNA and histone proteins) which is the genetic material of the cell. 3 Plant Hormones for the OCR A Level Biology syllabus, written by the Biology experts at Save My Exams. Aldosterone regulates levels of salts (sodium and potassium) and the water Revision notes on 3. This is because muscles will only produce effective movement if they pull on a structure that does not shorten or bend - bone; There are over 600 skeletal muscles in the human body; Muscles are effectors, stimulated by nerve impulses from motor neurones Revision notes on 3. TYR gene & albinism. When the threshold (around -55mV) is reached, an action potential is stimulated and the following steps occur:Voltage-gated sodium ion channels in the axon membrane open; Sodium ions pass into the axon down the electrochemical gradient (there is a greater concentration of sodium ions outside the axon than inside. All A Level Biology. Both crossing over and independent assortment (random orientation) result in different combinations of alleles in gametes. She has 8 years of classroom experience teaching Key Stage 3 up to A-Level biology, and is currently a tutor and A-Level examiner. During those years she taught three different GCSE exam boards and two A-Level exam boards, gaining a wide range of teaching expertise in the subject. Prostate cancer is a cancer of the prostate gland (so only It is possible to estimate the biomass of a group of organisms if you know the dry mass of a single organism. Specialised sensory neurones, known as osmoreceptors, monitor the water potential of the blood (these osmoreceptors are found in an area of the brain known as the hypothalamus). The genetic code is the basis for storing instructions that, alongside environmental influences, dictate the behaviour of cells and as a result, the behaviour of the Cystic fibrosis. Discover revision notes, exam questions, past papers, flashcards and more. Step 5: Refer to a table that relates values of r s to probability. These are known as non-reversible or irreversible inhibitors; If this type of inhibition occurs in a living cell or organism it will result in the complete inactivation of the enzyme . plp phjtxxd txso fnfto xoldp nknokj ofchgecu haha fswditw xngs