AS Biology Topic 1 Summary

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Explain why many animals have a heart and circulation (mass transport to overcome limitations of diffusion in meeting the requirements of organisms). (Activity 1.2)
Small organisms can survive by oxygen and carbon dioxide etc. diffusing in and out of them. However, larger animals which have a low surface area to volume ratio will need a circulatory system to circulate these substances with in their body.
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Explain the importance of water as a solvent in transport, including its dipole nature. (Activity 1.5)
Water is a polar molecule. This is beneficial in many ways. Firstly, it means that water is a liquid at normal temperatures. Secondly, many chemicals dissolve easily in water making them easy to transport. Thirdly, the specific heat capacity is high,
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Explain how the structures of blood vessels (capillaries, arteries and veins) relate to their functions. (Activity 1.6)
Arteries carry blood away from the heart. This blood is under high pressure so the walls must be thick, with lots of muscle and elastic fibre, and the lumen must be narrow. Veins carry blood under low pressure to the heart. The Veins have a wide lume
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Describe the Cardiac cycle (atrial systole, ventricular systole and diastole). (Activity 1.7)
Firstly, blood is pumped out of the atrium and into the ventrical. During this step, there is high pressure in the atrium, thus the name Atrial Systole. Then the Ventricles contract pushing blood out into the body. At this step, there is high pressur
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Relate the structure and operation of the mammalian heart to its function, including the major blood vessels. (Activities 1.3 and 1.4)
The right side of the heart pumps blood to the lungs whilst the left side of the heart pumps blood to the rest of the body. If the blood starts by coming into the right atrium via the vena cava, it is deoxygenated. It is then pumped into the right ve
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Explain the course of events that leads to atherosclerosis (endothelial damage, inflammatory response, plaque formation, raised blood pressure). (Activity 1.8)
Firstly, there is damage to the endothelium. This causes an inflamatory response. White blood cells and cholesterol move into the wall of the blood vessel. This deposit is called an atheroma. Calcium salts and fibrous tissue build up causing the athe
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Describe the blood clotting process (thromboplastin release, conversion of prothrombin to thrombin and fibrinogen to fibrin) and its role in cardiovascular disease (CVD). (Activity 1.8)
When blood comes into contact with collagen, thromboplastin is released from the damaged tissue and platelets. This converst Prothrombin into Thrombin. Thrombin then converts soluble fibrinogen into insoluble fibrin. If there is already an atheroma i
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Analyse and interpret quantitative data on illness and mortality rates to determine health risks (including distinguishing between correlation and causation and recognising conflicting evidence). (Activity 1.9)
Correlation - when an increase in one thing is accompanied by an increase in another (positive). (e.g. the length of a TV programme and the percentage of the class asleep) Causation - a change in one variable is responsible for a change in the other.
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Explain why people's perceptions of risks are often different from the actual risks (including underestimating and overestimating the risks due to diet and other lifestyle factors in the development of heart disease). (Activity 1.9)
People tend to overestimate the risks if something is involuntary, not natural, unfamiliar, dreaded, unfair or very small. Sometimes if the risk is far off into the future - like a heart attack - one will underestimate the chance of it happening. For
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Evaluate design of studies used to determine health risk factors (including sample selection and sample size used to collect data that is both valid and reliable). (Activity 1.10)
Cohort studies - a group of people are followed over time to see who develops the disease. Case-control studies - a group of people who have the disease are compared with a group of people who do not have the disease. (the groups's history is observe
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Describe the factors that increase the risk of CVD (genetic, diet, age, gender, high blood pressure, smoking and inactivity). (Age and Gender Activity 1.11. Genetic Inheritance Activity 1.19. Blood Pressure Activities 1.12, 1.13 and 1.22. Diet Activi
The main factors which increase the risks of CVD are a high blood pressure - high pressure could cause a break in the epithelial cells, obesity - large amounts of cholesterol and high blood pressure, blood cholesterol and other dietary factors, smoki
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Distinguish between monosaccharides, disaccarides and polysaccharides (glycogen and starch - amylose and amylopectin) and relate their structures to their roles in providing and storing energy (alpha-glucose and cellulose are not required in this top
sugars and starch are composed of many single sugar units put together. One of these units is called a monosaccharide. Two are called a disaccharide. Three or more become a polysaccharide. Starch (found in plants) is made up of polysaccharides in two
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Describe how monosaccharides join to form disaccharides (sucrose, lactose and maltose) and polysaccharides (glycogen and amylose) through condensation reactions forming glycosidic bonds, and how these can be split through hydrolysis reactions. (Activ
Sucrose is formed from a glucose and fructose sugar. Maltose is formed from two glucose sugars. Lactose is formed from a galactose and glucose sugar. The bond in Maltose is a 1,4 glycosidic link. It is know by this because the bond is made at its fir
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Describe the synthesis of triglyceride by the formation of ester bonds during condensation reactions between glycerol and three fatty acids and recognise differences between saturated and unsaturated lipids. (Activity 1.16)
Three fatty acids and one glycerol molecule make up one triglyceride molecule. The molecules bond with an ester bond again a condensation reaction. The bond is between an oxygen and carbon atom (the carbon has a double bond between an oxygen). A satu
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Analyse data on energy budgets and diet so as to be able to discuss the consequences of energy imbalance, including weight loss, weight gain, and development of obesity. (Activity 1.17)
If energy input is equal with energy output a normal weight will be maintained. If your enery input is less than your energy output, you will lose weight and vice versa. Obesity would be the outcome if much more energy is continually consumed than th
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Analyse and interpret data on the possible significance for health of blood cholestorol levels and levels of high-density lipoproteins (HDLs) and low-density lipoproteins (LDLs). (Activity 1.18)
HDLs can be thought of as the good cholesterol as a higher amount of this is good, where as LDLs are the cholesterol which is bad for you. LDL is the major component of cholesterol risk for CVD.
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Describe the evidence for a causal relationship between blood cholesterol levels (total cholesterol and LDL cholesterol) and CVD. (Activity 1.18)
Lots of studies done etc...
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Describe how to investigate the Vit. C content of food and drink. (Activity 1.21)
Juices titraited into a DCPIP solution till colour changes. find amount of Vit. C needed to change colour of DCPIP then you can find the amount in each fruit juice...
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Describe how the effect of caffeine on heart rate in Daphnia can be investigated practically, and discuss whether there are ethical issues in the ues of invertebrates. (Activity 1.23)
Daphnia put under microscope in slide with cotton wool and cirtain conc. of caffeine solution, then heart beats counted...
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Discuss how people use scientific knowledge about the effects of diet (including obesity indicators), exercise and smoking to reduce their risk of coronary heart disease. (Activity 1.17 and 1.25)
If it is known that a bad diet and smoking increase the risk of CHD, then people can have a good diet and not smoke, thus decreasing their risk of CHD. If exercise is know to decrease the risk of CHD more people can do it to reduce their risk.
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Describe the benefits and risks of treatments for CVD (antihypertensives, plant statins, anticoagulants and platelet inhibitory drugs).
ACE inhibitors (antihypertensives) lower the blood pressure. Side effects - dizziness, dry cough, abnormal heart rhythms and a reduction in the function of the kidney. Calcium channel blockers (antihypertensives) block calcium channels in the muscles
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Other cards in this set

Card 2

Front

Explain the importance of water as a solvent in transport, including its dipole nature. (Activity 1.5)

Back

Water is a polar molecule. This is beneficial in many ways. Firstly, it means that water is a liquid at normal temperatures. Secondly, many chemicals dissolve easily in water making them easy to transport. Thirdly, the specific heat capacity is high,

Card 3

Front

Explain how the structures of blood vessels (capillaries, arteries and veins) relate to their functions. (Activity 1.6)

Back

Preview of the front of card 3

Card 4

Front

Describe the Cardiac cycle (atrial systole, ventricular systole and diastole). (Activity 1.7)

Back

Preview of the front of card 4

Card 5

Front

Relate the structure and operation of the mammalian heart to its function, including the major blood vessels. (Activities 1.3 and 1.4)

Back

Preview of the front of card 5
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