Example: bachelor of science

State the definition of diffusion What is meant by a

Page 1 State the definition of diffusion What is meant by a concentration gradient? What is the definition of osmosis? What is meant by a partially

Tags:

  State, What, Diffusion, Definition, State the definition of diffusion what

Information

Domain:

Source:

Link to this page:

Please notify us if you found a problem with this document:

Other abuse

Text of State the definition of diffusion What is meant by a

Page 1 State the definition of diffusionWhat is meant by a concentration gradient?What is the definition of osmosis?What is meant by a partially permeable membrane?Describe what happens when an animal cell is placed in pure what happens when a plant cell is placed in pure what happens when an animal cell is placed in a concentrated solution (eg a high concentration of sugar).Why do sports drinks contain sugars?What happens if the ions and water lost during exercise are not replaced?Why do sports drinks contain ions and water?What is meant by active transport?Why is active transport important in living organisms?Page 2 A concentration gradient is a difference in the concentration of a substance between one region and another. A steep concentration gradient = a large difference in is the random movement of particles from a region of high concentration to a region of lower concentration (ie down a concentration gradient).A partially permeable membrane allows water molecules through but not other is the diffusion of water from a dilute solution (ie high concentration of water) to a more concentrated solution (ie low concentration of water) through a partially permeable water has a higher concentration of water than the cytoplasm of a cell. Water would enter the cell by osmosis. The plant cell wall prevents the cell from water has a higher concentration of water than the cytoplasm of a cell. Therefore water enters the cell by osmosis. An animal cell would swell and could drinks contain sugars to replace the sugar used in energy release (by respiration) during highly concentrated solution of sugar will contain a lower concentration of water than the cell cytoplasm. Water will move out of the cell by osmosis and the cell will drinks contain ions and water to replace the ions and water lost during sweating in the ions and water lost during exercise are not replaced, the concentration of fluids in the body becomes unbalanced and the cells do not work transport allows cells to absorb ions from a dilute solution (for example root hair cells absorb mineral ions from the soil by active transport).Active transport is the movement of substances from a low concentration to a high concentration (against the concentration gradient) using energy from 3 State four ways that organs are specialised for exchanging substances (eg by diffusion).State two ways that human organ systems are adapted for transport (eg diffusion) with an increased surface are soluble food molecules absorbed by villi in the small intestine? State two ways that villi in the small intestine are adapted to absorb the products of do scientists call the upper part of the body, where the lungs are found?How are the lungs protected?What do scientists call the lower part of the body, where the small intestines are found?How is the upper part of the body (the thorax) separated from the lower part of the body (the abdomen)?State the pathways of diffusion of oxygen and carbon dioxide in and out of the do we call the small muscles located between the ribs?What do we call the movement of air into and out of the lungs? Describe how the muscles in the breathing system cause inhalation (air to enter the lungs).Page 4 Alveoli increase the surface area of the increase the surface area of the small are specialised for exchanging substances (eg by diffusion) by: Having a large surface area Being thin to provide a short diffusion path Have an efficient blood supply (in animals) Being ventilated (in animals for exchanging gases).The villi are adapted to absorb the products of digestion by: having a large surface area having an extensive network of blood capillaries to rapidly remove the products of digestion. This ensures a steep concentration food molecules are absorbed by villi in the small intestine by diffusion and active lungs are protected by the upper part of the body, where the lungs are found is called the upper part of the body (the thorax) is separated from the lower part of the body (the abdomen) by the lower part of the body, where the small intestines are found is called the small muscles located between the ribs are called the intercostal from the air diffuses into the bloodstream and carbon dioxide from the bloodstream diffuses into the air. The intercostal muscles between the ribs contract, causing the ribcage to move out and up. The diaphragm contracts and becomes flatter. The volume of the lungs increases, the pressure of the lungs falls and air moves into the movement of air into and out of the lungs is called 5 Describe how the muscles in the breathing system cause exhalation (air to leave the lungs).How does carbon dioxide enter the leaves of plants?How do water and mineral ions enter are leaves adapted to increase the diffusion of carbon dioxide into the is the role of stomata in leaves?How do plants lose water vapour?State three conditions that increase the evaporation of water from the surface of happens when plants lose water faster than it can be replaced by the roots?What do scientists call the cells which surround stomata?What name is given to the system that transports substances around the body?What is the main type of tissue in the heart?What do scientists call the upper chambers of the heart?Page 6 Carbon dioxide enters the leaves of plants by diffusion. The concentration inside the leaves is low as the cells use it in photosynthesis. The intercostal muscles between the ribs relax, causing the ribcage to move in and down. The diaphragm relaxes and lifts up. The volume of the lungs decreases, the pressure of the lungs increases and air moves out of the are adapted by Flattened shape means a short distance for diffusion. Internal air enters the roots by osmosis. Mineral ions enter the roots by active mainly lose water vapour by diffusion through the stomata on the leaves. Stomata are pores on the surfaces of leaves. The stomata allow carbon dioxide to diffuse into the leaf and oxygen to diffuse plants lose water faster than it can be replaced by the roots, the stomata close to prevent conditions that increase the evaporation of water from leaves: Hot conditions Dry conditions Windy conditionsThe circulatory system transports substances around the are surrounded by cells called guard cells. These control the size of upper chambers of the heart are called the left and right main type of tissue in the heart is muscle 7 What do scientists call the lower chambers of the heart?Describe the flow of blood through the right side of the the flow of blood through the left side of the is the function of arteries?What is the function of veins?What is the role of the coronary artery?How can we treat narrowing arteries (especially the coronary artery)?What name do we give blood vessels in the is the role of capillaries?What do scientists call the liquid part of the blood?What is transported in the blood plasma?What is the role of red blood cells?Page 8 Deoxygenated blood from the body enters the right atrium through the vena cava. The atrium contracts and the blood enters the right ventricle. The ventricle contracts and the blood passes out of the pulmonary artery to the lower chambers of the heart are called the left and right carry high pressure blood from the heart. Arteries have thick walls and elastic fibres to deal with the high blood from the lungs enters the left atrium through the pulmonary vein. The atrium contracts and the blood enters the left ventricle. The ventricle contracts and the blood passes out of the aorta to the coronary artery branches throughout the heart, providing oxygen to the heart carry low pressure blood back to the heart. Veins have thinner walls than arteries. Veins often have valves to prevent blood flowing flows through the organs in blood vessels called capillaries. These are narrow and have very thin can treat narrowing arteries (especially the coronary artery) using a tube called a stent which is placed in the artery and keeps it liquid part of the blood is called the blood blood flows through capillaries, useful molecules such as oxygen and glucose leave the blood to the cells. Waste molecules (such as carbon dioxide) pass from the cells to the blood cells transport oxygen from the lungs to the blood plasma transports: Carbon dioxide from the organs to the lungs Digestion products from the small intestines to other organs Urea from the liver to the kidneysPage 9 State two adaptations of red blood is the role of haemoglobin?State one way that white blood cells are different from red blood is the role of white blood cells?What are platelets and what is their job?What is the role of xylem tissue in plants?What is meant by the transpiration stream?What is the role of phloem tissue in plants?What are the advantages and disadvantages of treating kidney failure by dialysis?What are the advantages and disadvantages of treating kidney failure by kidney transplant?Describe two waste products that have to be removed from the body?Describe how the kidney removes urea from the 10 In the lungs, haemoglobin combines with oxygen, forming oxyhaemoglobin. In the organs, oxyhaemoglobin splits into haemoglobin and blood cells are packed with the oxygen-carrying pigment haemoglobin. Red blood cells have no nucleus, allowing more room for blood cells are part of the immune blood cells have a nucleus. Red blood cells do not have a plants, xylem tissue carries water and mineral ions from the roots to the stem and are tiny fragments of cells and have no nucleus. They help blood to tissue carries dissolved sugars from the leaves to the growing regions of plants (eg shoots) and storage organs (eg vegetables such as potato).The transpiration stream is the movement of water from the roots, through the xylem and out of the leaves through transplants allow patients to lead a normal life (eg normal diet) and are only expensive initially. However, there is a shortage of kidney donors and patients must take drugs to prevent the kidney being rejected for the rest of their machines are widely available. However, users must follow a strict diet to reduce salt intake and urea production. Dialysis is also expensive in the long term. First the blood is filtered, removing all the small molecules All the sugar (eg glucose) is then reabsorbed. Ions are reabsorbed (as much as the body requires) Water is reabsorbed (as much as the body requires) All urea, excess ions and excess water are released as urineCarbon dioxide is produced by respiration and is breathed out via the lungs. Urea is produced in the liver when amino acids are broken down. It is removed by the kidneys as urine and stored in the bladder until 11 Describe how a kidney dialysis machine works?Describe what happens when a transplanted kidney is two ways that doctors can prevent a transplanted kidney from being do we drink more on hot days?How is body temperature sensed?Describe what happens if the core body temperature is too what happens if the core body temperature is too organ monitors and controls the concentration of glucose in the blood?If the blood glucose concentration rises too much, how does the body respond to bring it back down to the normal range?If the blood glucose concentration falls too much, how does the body respond to bring it back up to the normal range?How is glucose stored in the human body?What happens in type 1 diabetes?Page 12 The surface of cells contain proteins (antigens). When a kidney is transplanted, the patient s antibodies can attack the antigens on the donated kidney as they do not recognise them as part of the patient s patient s blood is on one side of a partially permeable membrane and dialysis fluid is on the other side. The dialysis fluid contains useful molecules (eg glucose and ions) at the same concentration as the blood so these are not lost from the blood. Urea diffuses from the blood into the dialysis fluid and is cool down by sweating. On hot days, more water is lost by sweating, so we drink more to replace a kidney with a similar tissue-type to the the patient with drugs that suppress the activity of the patient s immune the core body temperature is too high: Blood vessels supplying the capillaries in the skin dilate (widen). More blood flows through the capillaries so more heat is lost. More sweat is released by sweat glands. As the sweat evaporates, the body cells in the thermoregulatory centre in the brain sense the temperature of the blood flowing through the brain. Receptors in the skin detect the skin temperature and send impulses to the pancreas monitors and controls the blood glucose the core body temperature is too low: Blood vessels supplying the capillaries in the skin constrict (narrow). Less blood flows through the capillaries so less heat is lost. Muscles can shiver. Contraction requires respiration, releasing energy to warm the the blood glucose concentration falls too much, the pancreas senses this and releases the hormone glucagon into the bloodstream. This causes glycogen to be converted into glucose which is released into the the blood glucose concentration rises too much, the pancreas senses this and releases the hormone insulin into the bloodstream. The insulin travels to target cells and allows glucose to move from the blood into the type 1 diabetes, the pancreas does not produce enough insulin. The patient s blood glucose concentration may rise to a high is stored in the human body as the molecule 13 Describe how type 1 diabetes can be controlled?Describe the types of pollution that can be produced from human do humans reduce the amount of land available for other animals and plants?What is meant by deforestation?State two negative effects of is meant by biodiversity and state the effect of deforestation on is deforestation carried out?Why are peat-free composts important?State five problems linked to global from photosynthesis, how can carbon dioxide be naturally removed from the atmosphere?How can biogas be made?Why must the temperature of a biogas generator be controlled?Page 14 Water can be polluted with sewage, fertiliser or toxic chemicals. Air can be polluted with smoke and with gases such as sulfur dioxide (sulfur dioxide causes acid rain). Land can be polluted with chemicals such as pesticides and herbicides. These can then be washed into 1 diabetes can be controlled by a careful diet, exercise and by injecting insulin (usually around a meal).Deforestation is when trees are cut down (eg for timber) or burned down (to provide land for agriculture).Humans reduce land available for other animals and plants by building (eg houses), quarrying, farming and is the variety of animals and plants in a habitat. Deforestation reduces biodiversity as it destroys habitats. Burning (and microorganisms carrying out decomposition) increase the release of carbon dioxide into the atmosphere. Reduces the rate at which carbon dioxide is removed from the atmosphere and trapped as can be used to make compost for gardens. Peat is extracted from peat bogs and this releases large amounts of carbon dioxide into the atmosphere. Peat-free composts are made without is carried out because: The land can be used to grow biofuels (based on ethanol). The land can be used to graze cattle and for rice fields. Both of these release methane into the atmosphere (leading to global warming).Atmospheric carbon dioxide can be absorbed into oceans, lakes and ponds. The Earth s climate may change (eg weather patterns). The sea level may rise. Biodiversity may reduce. Migration patterns (eg birds) may change. Species may change the biogas generator is too cold, the microorganisms will respire slowly and generate little gas. If the generator is too warm, the enzymes in the microorganisms can can be made by anaerobic (without oxygen) fermentation of plant material / waste material containing carbohydrates. The biogas is mainly 15 State the advantages and disadvantages of small-scale biogas the advantages and disadvantages of industrial-scale biogas are the advantages of burning biogas as a fuel?What can we say about energy and biomass along a food chain?State two ways that we can increase the efficiency of food production by factory is it important that we maintain fish stocks and how can we do this?Why is the fungus Fusarium useful in food production?Describe the conditions required by is the role of the valves between the atria and ventricles of the heart?Page 16 Provides a large amount of biogas Temperature can be controlled electronically so that the maximum amount of biogas can be generated. The generator can be run continuously, increasing production. The fuel (eg animal manure) may need to be transported to the generator. Transport vehicles burning fossil fuels will release carbon dioxide. Can provide cooking fuel for families that are not near other fuel sources. Raw materials (eg cow waste) may be very close to the generator Temperature may be hard to control. The generator can be placed underground to keep cool in hot countries. The generator needs cleaning out and refilled (batch process), reducing a food chain, there is always less energy and less biomass at each stage. To make food chains efficient, we should reduce the number of stages. Biogas is generated from plant-based material (indirectly, in the case of manure). When the plants grow, they remove carbon dioxide from the atmosphere. So when they are burned, no additional carbon dioxide is added to the atmosphere (carbon neutral). Biogas is mainly methane. If this was not burned, it would enter the atmosphere. Methane is a powerful greenhouse we overfish, the fish may not be able to breed sufficiently to maintain the population. The fish species may become extinct. We can protect fish stocks by limiting fishing (fishing quotas) and using nets with holes large enough to allow young fish through so they can mature and factory farming, animals are kept in very controlled conditions, to reduce energy loss by respiration. This involves limiting their movement and keeping the temperature constant (so they do not have to waste energy keeping warm).Fusarium fungus is grown on glucose syrup under aerobic conditions. The protein is harvested and produces mycoprotein which is rich in protein and can be eaten by between the atria and ventricles of the heart prevent the blood from flowing backwards when the ventricles 17

Related search queries