B1, B2, B3 Revision

1. B1, B2, B3 Revision RN

2. R.Narasimhan BP: measured in mmHg Systolic pressure: maximum pressure the heart produces Diastolic pressure: blood pressure between heart beats Aerobic respiration: Glucose + oxygen  Carbon dioxide + water + energy Exercise creates an oxygen debt Measuring fitness: Strength, flexibility, stamina, agility, speed • Anaerobic respiration: • Glucose  Lactic acid + energy • Much less energy released than aerobic respiration • You breathe heavily to replace oxygen • Heart beats faster so blood carries lactic acid away to liver to be broken down BMI= mass (Kg) height (m)2 RDA: Recommended daily allowance Carbohydrase (produced in the mouth, pancreas and small intestine) breaks _______ (a carbohydrate) down into glucose: B1 Understanding ourselves Types of cancer: Benign tumours are slow to divide, harmless and do not spread Malignant tumours are cancerous, divide out of control and spread throughout the body RDA(g) = 0.75X body mass (Kg) Protease (produced in the stomach, pancreas and small intestine) breaks _______ down into amino acids: Protein deficiency - Kwashiorkor Inheritance- Parents who are both carriers of the Cystic fibrosis allele (c). Parents Cc x Cc Gametes C or c x C or c (egg/sperm) C c Possible Outcomes C 75% Normal c 25% sufferers Lipase (produced in the pancreas and small intestine) breaks fats (_____) down into fatty acids and glycerol: Words – blood, lipids, proteins, digestion, starch, smaller

3. Glucose rises (eat food) Cystic Fibrosis Caused by recessive allele (so two copies of allele are needed). A thick sticky mucus is produced affecting air passages and digestive systems Controlling Blood Sugar Controlled by the pancreas, diabetics do not produce enough insulin Treatments Injections or monitoring diet Insulin produced by the pancreas causes glucose to change to glycogen Normal blood glucose level Normal blood glucose level. Glucagon released and glycogen converted back to glucose Producing antibodies Glucose falls (exercise) Temperature Monitored by thermoregulatory centre in brain and receptors in skin. Too Hot -hair lies flat -blood vessels dilate so heat lost through skin -sweat produced Too Cold -goosebumps & hairs trap air -blood vessels constrict -no sweat -shiver, respiration releases heat Step 2: The cell produces antibodies to “fit” the pathogen Step 1: The lymphocyte “sees” the pathogen (microbe) Reflex action: Stimulus receptor  sensory neurone  relay neuron in spinal cord  motor neurone  response Concave lens and convex lens corrects refraction of light rays so the image lands on the retina Step 4: The pathogens are “eaten” by the white blood cells Step 3: The antibodies fit onto the pathogens and cause them to “clump”

4. DNA with bases Damaged cilia in a smoker’s air way Hormones of the menstrual cycle Lobed ears are dominant over ears with no lobes Vasoconstriction and Vasodilation Human male chromosomes

5. EVIDENCE OF EVOLUTION What evidence is there that evolution is happening? • HUMAN EVOLUTION • How are human beings different from apes? • bigger b_____ • w_____ upright NATURAL SELECTION D______ proposed the theory of e______ to explain how species change over time. There is v_______ between individuals, those that are better a_______ are more likely to s________ and r________, passing on favorable characteristics. • Fossil record is incomplete because: • Some body part decay quickly • Fossilisation is rare • There may still be fossils we have not found NATURAL ECOSYSTEM Ocean, dessert, grass land, rain forest ARTIFICIAL ECOSYSTEM Farm land, Aquarium, green house The up and down pattern of predator and prey population is called cyclic fluctuations LAMARCK Believed that acquired characteristics can be inherited Photosynthesis happens only during day but respiration happens both during day and night B2 Understanding the environment The presence or absence of an indicator species is used to estimate levels of pollution Example: Lichens • CHARLES DARWIN: Developed theory of natural selection based on survival of fittest • Genes pass on the successful characteristics to the next generation • COMPETITION • What resources are plants and animals in competition for? • Space • Food • Mate • EXTINCTION • Causes of extinction: • increased c_______ • New p________ • e_________ change • new d_________ Adaptation: features which help a plant or animal survive in an extreme environment,. Example: Polar bear, Camel and cactus Sustainable development is taking things from the environment but leaving enough behind to ensure a supply for the future and prevent damage PHOTOSYNTHESIS : Carbon dioxide + water ------ glucose + oxygen LINCOLN INDEX: Population = Number of animals number of animals Caught 1st time X caught 2nd time number of marked animals caught second time MUTUALISM: When both Organisms benefit, example: Pea plant and nitrogen – fixing bacteria

6. “Species” means “a group of similar organisms” which are capable of interbreeding to produce fertile offspring, e.g. dogs Hybrids: Hybrids are the result of breeding two animals form different species, they cannot reproduce and are sterile. Example: Tiger +Lion = Tigon Classifying organisms Organism Reproduction between species Labrador Poodle Labradoodle Plants Animals Mule Liger + = Have backbone No backbone Vertebrates Invertebrates Used to make cellulose for plant cell walls Used as energy Stored as starch Used to make plant proteins for plant growth Stored as fats and oils Amphibians Birds Reptiles Fish Mammals glucose Photosynthesis Zebroid Geep Oxygen Ecological niche: The role of an organism in an ecosystem is called its ecological niche. Example: Native red and American grey squirrels. In Britain, there are 2 types of squirrels which occupy same ecological niche and there is a competition leading to decline in number of red squirrels. Used in respiration Released into air Direct products of photosynthesis

7. Cytoplasm: chemical reactions take place Cell membrane: Controls movement into and out of the cell Nucleus: contains genetic information Mitochondria: Respiration takes place providing energy Nitrogen bases: Adenine pairs with Thymine Guanine pairs with cytosine DNA is a double helix Genetic instructions are in the form of a code made up of 4 bases Protein synthesis: Each gene codes for a particular protein B3 Living and growing

8. 1) 2) 3) Haemoglobin + oxygen  Oxyhaemoglobin Platelets: are tiny pieces of cell, which have no nucleus. Important for clotting Plasma: straw coloured liquid which transports carbon dioxide, glucose, waste products, hormones and antibodies White blood cells: protect body against disease Red blood cells: transport oxygen from lungs to the tissues, disc shaped and no nucleus Enzymes have an optimum temperature and pH. Changes in pH/temp can denature the enzyme so its shape changes and the substrate can’t bind to the active site Uses of Enzymes -Biological washing powders -In baby foods -In slimming foods- fructose is made using isomerases. Fructose is sweeter than glucose so less is needed. Enzymes –biological catalysts that speed up reactions e.g. respiration in the mitochondria 1) Enzyme and substrate 2)Substrate binds to active site 3) Substrate is broken down Mitosis-used for normal cell growth 1) Parent cell 2) Chromosomes make identical copies of themselves 3)They line up along the centre 4) They move apart 5)Two daughter cells form each with 46 identical chromosomes to the parent cell Meiosis –used to make the sex cells (gametes) -the chromosomes are copied -cell divides twice to give four cells Heart pumps blood around the body Arteries transport blood away from the heart Veins transport blood into the heart Capillaries exchange materials with tissues Enzymes and digestion Large molecules are broken down so they can be absorbed. -Amylase breaks down starch into sugars in the mouth and small intestine. -Proteases breakdown proteins into amino acids in the stomach and small intestine. -Lipases breakdown fats into fatty acids and glycerol in the small intestine.

9. Cytoplasm Chloroplast Vacuole Nucleus Cell Membrane Cell Wall Used in lungs O2 diffuses into the blood and CO2 diffuses into lungs Photosynthesis Carbon dioxide + Water Glucose + Oxygen Cell growth Light and chlorophyll are also needed Cell division 3 Limiting factors -light -temperature -CO2 At first as CO2 increases so does photosynthesis but only up to a certain point Here light or temperature is the limiting factor. Cell expansion Cell differentiation