Transport and excretion

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(Biology 3) Flashcards on Transport and excretion, created by zolas_horses on 13/05/2013.
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Question Answer
Why may a kidney be rejected by the body? They have a different tissue type
How can the chance of rejection be minimized? Matching similar tissue type so a family member (close as possible)
What are the advantage of taking anti rejection drugs? You become susceptible or more prone to other infections.
What are the causes of kidney disease? Diabetes, High blood pressure, glomerulonephritis, polycystic kidney disease, scarring from kidney infection in childhood and obstruction
What would the effects of kidney disease be? You find proteins/ blood or sugar in the urine or too much water may be present in the blood
What are the two main types of treatment for kidney disease? Dialysis - Using a mechanical kidney to restore the concentrations of dissolved substances in the blood to normal level Transplant - Replacing the diseased kidney with a healthy one from a donor of a similar type to the recipient.
What are the advantages of a Xenotransplant? Freedom from dialysis, Increased energy, Fewer dietary requirements, Feeling better physically, A better quality of life, no longer see yourself as chronically ill.
What are the disadvantages of a Xenotransplant? The donor kidney can be rejected by the body so you have to take drugs that suppress the immune system, side effects may occur, surgery under general anaesthesia is needed, There are limited donors, matching kindey type is needed more likely to be a close family member it could also lead to the black market buying and selling of kidneys.
What are the advantages of dialysis? Reasonable quality of life, non invasive (surgery)
What are the disadvantages of dialysis? Needed 5 hours a day 3 times a week on a machine, restricts the patients diet, expensive and is only a short term option
What types of materials pass into the bowman's capusle from the glomerolous? Water, salt, urea and glucose
What does the kidney machine do? It removes excess salts and urea. It is done by diffusion across a selectively permeable membrane or dialysis tube. The urea passes through a membrane into a dialysis fluid. It is important that useful substances in the blood are not lost e.g. glucose and salts. To prevent this dialysis fluid contains the same concentration of these as blood plasma. This ensures that only urea, excess salts and water diffuse into the dialysis fluid.
Why are some materials e.g. protein not filtered by the kidneys? The molecules are too big to pass through. (Acts like a sieve)
What process controls the amount of water in our bodies? Osmoregulation
How does water pass into and out of our bodies? When we drink water and eat water passes into our bodies. It leaves via sweating and excreting.
Why is it not possible to regulate water loss by stopping sweating? It is to maintain body temperature
Describe how the volume and concentration of urine would change if you need to conserve water? You produce less urine which is more concentrated
Describe how the volume and concentration of urine would change if you need to lose water? You produce a lot of urine which is less concentrated
What is blood concentration measured by? The brain
When there is less water in the body what happens? The brain releases a hormone called ADH (anti-dieuretic hormone).
How does ADH reach the kidneys? It is transported in the blood stream via the endocrine system.
What does ADH do? It causes teh tubules to reabsorb more water into the blood stream, making our urine more concentrated.
How is the high pressure used by ultra filtration created? It is created when the blood passes through changing diameters. The blood vessels a the start of the capillary knot is a lot wider than the blood vessels leaving the cpaillary knot
What does the absorption of minerals by the root hair depend on? Active transport
How does active transport differ from diffusion? Active transport moves the ions against the concentrationgradient (low to high) and energy is required.
What does the blood consist of? Cells (55%) and Plasma (45%)
What is the function of red blood cells and describe them? The red blood cells carry oxygen around the body (attaches to haemoglobin). It is a round shape with a bioconcave disk in the middle.
What is the function of white blood cells and describe them? White blood cells fight diseases -Phagocytes (engulf (eat) microbes) -Lymphocytes (produce antibodies (memory cells)). They have an irregular shape and often have more than one nucleus, they have a triangular shape in the middle connected by black dots at each point, but with only two lines.
What is the function of platelets and describe them? Platelets clot the blood and help to seal wounds. They are just cell fragments.
What is the function of the plasma and describe it? It is a straw coloured liquid that carries/transports materials e.g. glucose, minerals, water, heat and hormones. It also removes waste products such as urea and CO2
What gives blood its characteristic colour? The oxygen attached to the haemoglobin
Why is it an advantage that red blood cells do not contain nucleus'? It gives them more room to carry oxygen
State the way the blood travels on the right side of the heart? The deoxygenated blood enters through the vena cava into the right atrium, from here it passes past the valve into the right ventricle which then pumps the blood to the pulmonary artery. The pulmonary artery takes the deoxygentaed blood to th elungs to be oxygenated.
State the way blood travels on the left side of the heart? Oxygenated blood travels into the left side of the heart through the pulmonary veins from the lungs, it then enters the left atrium. The blood passes through the valves into the left ventricle which has a very thick wall so that the blood can be pumped through the aorta and round the whole body.
Why does blood need to go through the heart twice? There are two contractions. the first to pump the blood to the lungs, the second to pump the oxygenated blood to the body.
How wide is a capillary? Width of a red blood cell (one cell thick)
Name two adaptations of capillaries? 1)Thinner walls, shorter diffusion distance. 2) Lots of vessels rather than one artery, larger surface area, so there is more blood in contact with the walls, slows the blood flow so there is more time for diffusion
Which process allows oxygen and food to leave the capillaries? Diffusion
What passes out of capillaries? Oxygen passes out of capillaries into cells because they need oxygen to function and CO2 is passed back into the capillary
Whts is the job of the heart valves? To prevent blood backflow
What is the waste product removed by the kidney called? Urea
What do the kidneys do other than excrete urea? They regulate water content and remove excess salts
Describe the excretory system? Blood is carried to the kidneys where it is cleaned. The waste product is called urine (a mixture of urea and excess salts). The urine is carried out of the kidneys to the bladder in tubes called ureters. The bladder then hold the urine until it is excreted out of the ody by a tube called the urethra.
What are the three mian parts of the kidney? The pelvis, the meddula and the cortex.
What is the working unit of the kidney? The nephron, it is microscopic in size
What is the ultra filtration? Ultra filtration occurs in the Glomeroulous . Here filtration occurs under high pressure, with only small molecules being able to pass through.
What is selective reabsorbtion? This occurs in the loop of henle. The closer the blood supply the quicket and easier the absorption is. This is where useful substances are taken back into the blood stream.
What is osmoregulation? Osmoregulation takes place in the collecting duct and is where water control takes place. If water is needed it is reabsorbed into the blood and if it is not it is excreted.
How does the nephron work? It works by filtering the blood under high pressure as it passes trhough the capillary knot.
How does transpiration help the upward movement of water? Water is lost from the leaves which causes more water to be dragged up to replace it by osmosis (from high concentration to low concentration)
LEARN (Vascular bundle holds the xylem and phloem)
What is the purpose of the waxy cuticle on a leaf? To prevent excessive water loss
What is the purpose of the Guard cells? They contain chloroplast so photosynthesis. This gives them a lower water concentration so water passes in via osmosis, this makes them turgid. When turgid they open the stomata.
What is the purpose of the palaside layer? This layer contains lots of chloroplasts. The majority of photosynthesis occurs in this layer.
What is the purpose of the stoma? The stoma are tiny holes or pores in the leaves surface and are located within the lower epidermis. This is where water is lost through the leaves but also where CO2 passes in
What is the purpose of the mesophyll layer? This is where gases diffuse. CO2 diffuses in and O2 diffuses out. Water also evaporates from these spaces into the surrounding areas where it will diffuse into the stoma.
What is the purpose of the lower epidermis? It is the area which holds the stomata and where gases and water diffuse in and out.
Which process is used to make the sugars in the plants and how are they used? Photosynthesis, the plants use these sugars immediately for respiration and some is stored as starch.
Which group of chemicals are made with them minerals that plants absorb? Proteins
What are the three main mineral requirements for a plant? Nitrogen, Potassium and Phosphorus
Why is nitrogen necessary for plants? Nitrate is used for growth, it is used in protein and DNA synthesis.
Why is potassium essential for plants? Potassium ions are needed for photosynthesis, without them you would have yellowing leaves.
Why is phosphorus essential for plants? Phosphorus is needed for protein and DNA synthesis and without it the plant would have very poor root growth.
What fertiliser can encourage plant growth? NPK fertiliser
How do plants use water? -Photosynthesis (raw materials) -Support (through pressure from the vacuole) -To transport minerals around the plant -Cooling
How does the water enter the plant? Through the roots via the root hair cells
A = Vacuole B = Cell membrane C = Cell wall D = Nucleus E = Cell membrane
How does water enter the root hair cell? Osmosis
How is the root hair cell adapted to absorb water and minerals? - Large surface area - Thin walls -Numerous amounts present
How is the root hair cell adapted to anchor the plant? - It has sideways growth - Grows between the soil particles
Describe root pressure? Root pressure is the way that water is absorbed and pushed up and around the plant
How is water lost and how does this cause a constant flow of water through the plant? It is lost through transpiration. A process where water is evaporated from the leaves through the tiny pores called stomata. This combined with osmosis creates a constant flow of water
How do we measure how much water plants lose in transpiration? With a potometer
Why do we use a layer of oil in the potometer? To prevent H20 evaporating from the measuring cylinder
Why do we use a woody shoot in the potometer experiment? Because it has less stomata, so water is only lost through the leaves in the experiment
What two tubes make up the circulatory system? Xylem - Which carries water and minerals up the stem to the leaves Phloem - Which carries water and food (sugar created in photosyntheses) away from the leaves
Name and explain 2 properties of water that enable it to move upwards against gravity in the stem? -The molecules are sticky and attracted to each other (H2O +H2O -Adhesion (H2O + the wall of the xylem vessel)
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