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Detects changes in the Brain environment Coordination Pancreas centres Receptors detect changes in Receptor temperature, Control systems Spinal cord glucose Coordination concentrations centre sends and water levels instructions to the effectors Body temperature Effectors Blood glucose Controls... 5.1 HOMEOSTASIS concentration Water levels Homeostasis maintains Bring about responses to stimuli temperature, glucose concentrations and water Muscles levels Glands Maintenance of a constant internal environment in order to ensure optimum conditions for enzyme and cellular function AQA https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc

Muscles Transmits impulse Transmits signal from Detects stimulus Detect stimulus Effectors Glands to effector sensory to motor neurone Allow reaction to surroundings and the Motor synapse Relay synapse Sensory Carry out a Spinal cord neurone neurone neurone coordination of response actions Receptors Central Coordinator Nervous System Brain Function Transmission Membranes prevent some drugs from Subconscious Reflex arc reaching the brain Via neurones Complex Delicate Importance 5.2 HUMAN NERVOUS SYSTEM PART 1 Protection Fast, Difficulties automatic Cerebellum Brain Investigation + Electrical Structure Treatment stimulation Balance Cerebral Methods cortex Medulla Studying patients with brain damage Coordination Muscle movement MRI (comparison of KEY Conscious Non-voluntary symptoms) thought movement ‘Higher tier only’ AQA written in orange. Heart rate ‘Biology only’ Personality Breathing rate written in clouds. Language https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc

Allows light into Shivering Sweating the eye to focus on stops Carries impulses the retina from the eye to Vasoconstriction the brain Vasodilation Receptors in skin Cornea Sweating Detects blood increases temperature Tough outer layer, protects Optic nerve Light sensitive Too low Coordinator layer at the back internal Too high structures of the eye Contracts/ relaxes to Temperature Retina control the amount of light entering the eye Sclera Iris Structure Control the 5.2 HUMAN NERVOUS SYSTEM shape of the PART 2 lens Stronger Suspensory The eye Replacement refraction ligaments + lenses ciliary muscles Accommodation Treatment Ciliary muscles Disorders Glasses contract, suspensory Close object Focusing Hyperopia ligaments loosen, lens thickens Myopia Laser eye surgery KEY Distant object Lens too flat Ciliary muscles Weaker refraction Lens too Contact ‘Biology only’ relax, suspensory curved Light focused lenses written in clouds. ligaments contract, behind the Light focused in retina lens thins front of the retina AQA https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc

Pancreas releases insulin → Stored in liver Body cells do Exercise regime glucose moved back into cells and muscles as not respond to glycogen Insulin injections insulin Pancreas secretes Too low Type 1 Type 2 Carbohydrate glucagon so glycogen controlled diet Diabetes is converted to Too high Obesity is a glucose and released risk factor Insufficient Fight-or- Controlled by the insulin is Adrenaline flight pancreas Thyroxine produced by the response pancreas -ve feedback Blood glucose Lungs during Increases basal exhalation metabolic rate Absorbs more 5.3 HORMONAL COORDINATION IN HUMANS Sweat through skin water into the blood PART 1 Loss of water Advantages: ADH is released by the Filtration of Excess removed Reduced urea, blood pituitary gland when blood by kidneys glucose level same, water level is too low water and ion balance Acts on regulated Water Excess amino acids balance deaminated in liver, Urea diffuses out converted to urea Disadvantages: Time consuming, Excreted in KEY restrictive diet, cannot be Disease Kidneys AQA used indefinitely Dialysis Selective reabsorption of ‘Higher tier only’ Blood is drawn into Transplant glucose, ions, written in orange. machine, flows next to dialysis fluid, separated water ‘Biology only’ written in clouds. by a membrane https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc

Oestrogen: Testosterone: HT: FSH: Stimulates ovulation Sperm production Oestrogen maturation stimulates of an egg in Oestrogen + the release the ovary LH: Progesterone: stimulates maintains uterine of LH release of an Secondary sexual lining egg characteristics at Reproduction Menstrual FSH stimulates the puberty Cycle release of oestrogen from a mature egg FSH + LH given to 5.3 HORMONAL COORDINATION IN HUMANS Oral contraception: stimulate maturation inhibits FSH of eggs, which are IVF PART 2 collected and fertilised Contraception Surgical Intrauterine device sterilisation Embryos are then injected into Disadvantages Barrier e.g. condom, Spermicidal prevent meeting of agents mother’s uterus Risk of multiple births sperm and egg AQA Stress Abstaining from sex Injection, implant, around ovulation patch of slow release KEY Low success rate progesterone ‘Higher tier only’ written in orange. https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc

Used to artificially Both controlled by Geotropism, aka end seed dormancy the hormone auxin gravitropism Initiate seed Used to promote Phototropism germination and end flowering Response to Control and coordination Response to seed dormancy. Used to increase light gravity Causes bolting in fruit size adult plants, leading to flower and seed production Control growth and coordination Gibberellins 5.4 PLANT HORMONES Used in rooting powders to promote (biology only) root growth Ethene Uses of plant hormones Auxins Can promote growth of tissue Controls cell Used to control Used as a weed killer - division and fruit ripening. Fruit is ripened makes weeds grow too cultures quickly, leading to plant ripening after transport to prevent spoiling death KEY ‘Higher tier only’ AQA written in orange. https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc

No mixing of Produces Allows selective Advantages Allows natural selection Mixing of genetic clones breeding by humans to increase the chances of genetic surviving environmental information information Mitosis to increase food production changes Creates variation Certain plants No fusion of One parent Sexual Pollen and and fungi gametes egg Flowering plants Types of Sperm and Asexual reproduction egg Both types 6.1 REPRODUCTION Fusion of male and Animals female gametes Malarial Produces a Advantages PART 1 Gametes Fertilisation = parasite large number produced by fusion of gametes of offspring Faster than No need for Sexual sexual mate meiosis Fertilisation reproduction in restores the full reproduction Time and energy Meiosis no. of chromosomes mosquitos, efficient asexual Halves the no. of Process chromosomes to reproduction in produce gametes humans KEY Gametes are Cell divides Cell divides by Genetic AQA genetically twice to produce mitosis then information ‘Biology only’ different differentiates written in clouds. 4 gametes is copied https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc

A to T, G to C Nucleotides XY XX Cystic fibrosis made of sugar, Polydactyly phosphate and Male Identification of genes linked to diseases Inherited base Sex Female disorders (A, T ,G, or C) Importance Tracing past human Organised into 2 strands form Contributes to migration patterns chromosomes a double helix the phenotype Polymer Structure Change in structure Four types of 6.1 REPRODUCTION may lead to a change repeated PART 2 in the protein nucleotides Altered shape Sequence of 3 DNA Non-coding Controls or function nucleotides codes DNA expression of gene for an amino acid in The entire genetic KEY material in an Genome Recessive a protein organism Dominant ‘Higher tier only’ Gene written in orange. Carriers bring Allele: amino acids to the different form ‘Biology only’ written in clouds. template in of a gene correct order Synthesised using A section of DNA that codes Genotype The alleles of AQA a template on for a sequence of amino an organism ribosomes acids to make a protein https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc

Change in inherited Phenotype determined by Mutations occur Breed organisms with characteristics over interaction between genotype continuously but most desirable qualities do not result in a new time and environment Mutations cause new phenotype characteristics Due to natural Continuous Selective breeding Genes from other selection organisms can be added process Evolution Variation Bacteria modified to produce insulin Involves modifying Can lead to an organism's genome Different habitats to give it desirable have different formation of new Genetic characteristics desirable qualities, so species engineering Risks: loss of natural selection biodiversity, GM crops occurs differently 6.2 VARIATION AND EVOLUTION are expensive, long- New species formed when term health impacts organisms can no longer unknown interbreed to produce fertile Produces offspring with identical genetic offspring GM crops are resistant to Benefits: improve crop yield, information to parent disease, can produce better produce materials for medicines, Cloning fruit and are frost resistant less waste Used to preserve rare Other cloning methods: Process: plants tissue culture/cuttings 1. Desirable gene isolated using enzymes 2. Gene inserted into vector (usually (plants), embryo bacterial plasmid/virus) transplants (animals) 3. Gene transferred to target organism KEY Cloning animals: early in development ‘Higher tier only’ 1. Remove nucleus from unfertilised egg cell AQA written in orange. 2. Replace with nucleus from adult body cell (e.g skin cell) ‘Biology only’ written in clouds. 3. Give egg cell an electric shock - stimulates cell division 4. When embryo develops, place in womb of adult to develop https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc

Compare ancient organisms to Proves that bacteria are evolving, e.g. current organisms MRSA Fossils Antibiotic resistance Complete course of antibiotics Now proof that characteristics are passed Evidence for Only prescribe where Parents pass characteristics onto offspring in genes evolution needed/restrict to offspring through ‘units’. agricultural use These are now known as genes Organisms with beneficial characteristics are more likely to survive and reproduce so Gregor Mendel: crossed pea pass them on to their offspring plants with different characteristics in order to study Charles Darwin: Theory of 6.3 GENETICS AND EVOLUTION how characteristics are inherited proposed theory of evolution (mid 19th century) evolution by natural Alfred Russel Not initially Wallace Genetics selection accepted due to religious beliefs Now widely accepted as true due to at the time Speciation Late 19th century: chromosomes improvements in technology finding new observed during cell division evidence, as well as the science behind Extinction Mid 20th century: DNA structure determined it being understood. Population splits and the KEY A new species is formed two groups become No remaining living Due to: habitat AQA when the groups can no isolated for a long time - individuals in a destruction, hunting, ‘Biology only’ species written in clouds. longer interbreed to evolve differently, climate change, produce fertile eventually form new pollution, competition offspring species https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc

You can remember this by ‘King Philip Cooks On Four Gas Stoves’ Kingdom → Phylum → Class → Order → Family → Genus → Species Includes protists, Linnaean system classified Not accurate - animals in the fungi, plants and organisms using structure same environment can evolve to look similar, despite being very animals and characteristics different genetically (e.g. rabbits Linnaean system and hares) Eukaryota Developed by 6.4 CLASSIFICATION Originally classified based on physical Carl Linnaeus OF LIVING ORGANISMS characteristics and behavioural similarities Bacteria Three domain system Primitive bacteria Developments in Developed by Archaea classification Carl Woese Live in extreme environments Developments in technology meant that internal cell structure could be seen and genome sequencing could occur, which makes classification much more accurate. Organisms are now grouped by how close their genomes are. AQA https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc

Different plants and animals are adapted to Stable when population size remains different habitats. If habitat conditions change constant. This happens when rapidly, organisms may be unable to adapt to the Non-living Competition- there is organisms and environmental factors changes and die. competition for food, are balanced resources, mates and space. factors Competition promotes Removing species evolution and natural leads to imbalance Light intensity, temperature, Abiotic factors selection If one species is removed it humidity, soil pH, wind, salinity, can affect other species in CO2/O2 levels etc. the community Biotic and abiotic factors interact in an Communities ecosystem Predation - organisms which 7.1 ADAPTATIONS, INTERDEPENDENCE Interdependence - different have lots of predators are AND COMPETITION species depend on each other e.g. more likely to be killed for food, shelter, or to spread seeds Competition between species - not Extremophiles are adapted to live in enough resources for all, results in extreme environments death of weaker organisms Biotic factors Disease - reduces population Adaptations size by killing organisms. In densely populated areas, Food availability - a large amount of Adaptations can Organisms adapt to be structural, new conditions disease can spread quickly food means that organisms can breed behavioural or through evolution and so a large proportion of the Living more successfully. Food shortages functional natural selection population is killed. factors lead to a high death rate which results AQA in a slow or negative population growth. https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc

Temperature Composition of Biomass is produced by atmospheric gas photosynthetic organisms Producers are eaten (producers) by consumers Changes affect Changes can be Sampling methods Levels of organisation Consumers are distribution of seasonal, geographic (quadrats, transects) eaten by show distribution and secondary species or human-related abundance of species consumers Water availability Environmental change Methane can be used as Food chains show direction of fuel in biogas generators transfer of biomass Materials cycle Without oxygen 7.2 ORGANISATION OF THE ECOSYSTEM through biotic and abiotic components of present, decomposers the ecosystem work anaerobically. This is slow and Carbon cycle releases methane gas Decomposition Warm temperatures = Material cycling which is bad for the faster decay (optimum temperatures for enzymes) environment (greenhouse gas) Water cycle Different factors may interact e.g. soil water levels directly affect the Decompositions returns materials to KEY volume of oxygen in the soil Microorganisms help return the environment materials to the soil ‘Higher tier only’ No water = slow decay, as (material ‘cycling’) written in orange. decomposers need water to survive. (minerals) and air (CO2) Too much water = less oxygen, so during decay AQA ‘Biology only’ written in clouds. anaerobic decomposition occurs https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc

Consequently less space for Habitat Breeding Reintroduction of other animal/plant habitats Burning/decay of peat protection programmes species releases a large Number of organisms and volume of CO2 variety of species in an area, as well as the Maintaining biodiversity Land used up by growing diversity of their genes infrastructure: homes, Habitats destroyed Large Biodiversity Reduction of Recycling farms, landfills, mining for resource biodiversity leads deforestation and waste harvesting: to a more stable and quarrying quarries, replanting Recycling ecosystem reduces waste Land use deforestation, peat Must manage in landfill and bogs for compost pollution of air, water and land lessens the Growing population 7.3 BIODIVERSITY AND THE EFFECT OF need to source = more space HUMAN INTERACTION ON ECOSYSTEMS new raw materials needed for Leads to soil erosion, Rising temperatures lead to Waste infrastructure extinction, flash flooding and extinction of species that management release of greenhouse gases cannot adapt e.g. coral reef Deforestation Growing population leads to more Major cause of Greenhouse waste and a higher demand for habitat gases are linked raw materials Make space for destruction to global crops and warming Global warming animals Leads to more Caused by increased release of natural disasters greenhouse gases, such as CO2 AQA and methane https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc

Shows the total The final trophic The trophic level of an Level one - producers, mass of organisms in level is made from organism refers to its position photosynthetic organisms each trophic level of apex predators which in the food chain, food web or a food chain. Level are carnivores with which use energy from one is at the bottom no predators e.g. pyramid of biomass light to produce biomass (about 1% of light is used) Pyramids of biomass humans Trophic levels Level two - primary Decomposers break down consumers, herbivores eat dead organisms using extracellular digestion plants/algae 7.4 TROPHIC LEVELS IN AN ECOSYSTEM Level three - secondary consumers, carnivores eat (biology only) herbivores Biomass is lost between trophic levels: Transfer of biomass ● Not all plant/animal material digested Level four - tertiary ● Biomass lost through excretion/decay Biomass is created by consumers, carnivores eat ● Biomass used in other processes e.g. producers and is passed movement and keeping warm secondary consumers along the food chain About 10% transferred to next level. through feeding AQA https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc

Fusarium produces Allows efficient food Introduce Control net mycoprotein production through fishing size microorganisms quotas Prevents extinction of fish species Genetic engineering/ Biotechnology and modification food production Bacteria can be Higher yield and Sustainable fisheries modified to produce less wastage of insulin for diabetes Ensures fish produce populations do not decline 7.5 FOOD PRODUCTION (biology only) Use of pesticides, herbicides and fertilisers Natural Increasing birth disasters and High cost of Farming techniques rate, decreasing climate change agricultural inputs High food demands death rate Factors affecting food security mean that efficiency Changing diets - increasing demand and yield must be for meat in Limit energy loss: restrict maximised developing countries movement, keep at optimum Pests and War and temperature, minimise Selective breeding and disease conflict disease genetic modification AQA https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc