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Exchange and Transport

Gemma Bradford Biology f211 A-Levels English 85 cards

Cards in this deck (85)

  1. 1Explain the features on one heartbeat on an ecgP wave - contraction of atria
    QRS complex - contraction of ventricles
    T wave - relaxation of ventricles
  2. 2How do you calculate heart rateHeart rate (bpm) = 60/ time taken for one heartbeat (s)
  3. 3What is the normal range at rest for an adult heart rate60-100 bpm
  4. 4What is fibrillationAn irregular heartbeat that can result in fainting
  5. 5Describe an arteryCarry blood from heart to rest of body, thick muscular walls with elastic tissue, endothelium is folded, small lumen
  6. 6Describe a capillaryBranched from arteries, connecting to veins, exchanges substances between itself and other cells, one cell thick endothelium, large lumen
  7. 7Describe a veinTake blood back to the heart, thin muscular wall with little elastic tissue large lumen, contain valves
  8. 8What is tissue fluidFluid surrounding cells in tissues, made from substances that leave the blood
  9. 9What is the difference between a source and a sinkSource = where assimilates are produced
    Sink = Where assimilates are used up
  10. 10What is a capillary bedNetwork of capillaries in an area of tissue, where substances move out of capillaries into tissue fluid by pressure filtration
  11. 11What is translocationMovement of assimilates from source to sink
  12. 12Give an example of translocationSource for sucrose is leaves, sinks are food storage organs/meristems
  13. 13How do enzymes maintain a concentration gradient from source to sinkBy changing dissolved substances at the sink into something else/breaking them down to lower concentration at sink
  14. 14What are assimilatesSubstances that become incorporated into the plant tissue - sugars
  15. 15Describe the start of a capilalry bedNearest to arteries, high hydrostatic pressure forcing fluid out of capilalries and into space around cells = forming tissue fluid
  16. 16What is transpirationEvaporation of water from a plant's surface as a result of gas exchange for photosynthesis
  17. 17How does light affect transpiration rateStomata open more in more light = allowing for more water to evaporate out
  18. 18Describe the end of a capillary bedWater potential is lower than in tissue fluid, so some water re-enters by osmosis, low hydrostatic pressure
  19. 19How does temperature affect transpiration rateWarmer water molecules have more energy, so they evaporate from cells inside leaf faster = increasing water potential gradient between inside and outside of leaf
  20. 20How does humidity affect transpiration rateIf air around stomata is dry, water potential gradient between leaf and air is increased
  21. 21Give a difference between blood and tissue fluidTissue fluid does not contain any red blood cells or big proteins, as they are too large to be pushed out of capillary walls
  22. 22How does wind affect transpiration rateAir movement blows away water molecules from around the stomata, increasing water potential gradient
  23. 23Name 4 precautions to take when setting up a potometer1. Cut shoot underwater and at a slant
    2. Assemble potometer and insert shoot underwater
    3. Dry leaves
    4. Allow time for shoot to acclimatise before shutting tap
  24. 24Name 4 adaptations of xerophytic plants1. Stomata sunk in pits
    2. Curled leaves
    3. Layer of hairs on epidermis
    4. Less stomata
  25. 25What does a potometer testEstimates transpiration rate by water uptake of the plant, can test effect of different factors on rate
  26. 26What is the lymphatic systemWhere the tissue fluid did not re-enter at end of capillary bed, so instead enters lymph vessel = becoming lymph
  27. 27Why does rate of transpiration fluctuate at different times of the dayBecause factors are not constant
  28. 28How does water enter a plantSoil - root hair cells - root cortex including endodermis - xylem
    Osmosis
  29. 29Describe haemoglobinFound in red blood cells, carries oxygen around the body, can carry 4 oxygen molecules, large protein with quaternary structure, made of four polypeptide chains each with it's own haem group
  30. 30Does soil have a high water potential or lowHigh, so it diffuses into the root hair cells
  31. 31Do leaves had a high or low water potentialLow
  32. 32Describe the symplast pathwayTravels through cytoplasm of cells and through plasmodesmatas to reach xylem vessel
  33. 33Describe the apoplast pathwayGoes through cell walls, blocked by casparian strip where it takes the symplast pathway to reach the xylem vessels
  34. 34Outline the association and disassociation of oxygenLungs = oxygen joins to iron in hb to form oxyhb
    Body cells = oxygen leaves oxyhb and turns back into hb
  35. 35What is a transpiration streamMovement of water from roots to leaves
  36. 36What is association of oxygenLoading of oxygen onto hb
  37. 37What is cohesionWhere water molecules are attracted to eachother, so the whole column of water moves up the xylem
  38. 38What is tensionAs water evaporates from leaves, this creates a suction pulling more water into leaf
  39. 39What is disassociationUnloading of oxygen from oxyhb
  40. 40What is adhesionWhere water molecules are attracted to the xylem vessel walls, helping water to rise up through vessels
  41. 41What is affinity for oxygenTendency a molecule has to bind with oxygen
  42. 42What is the casparian stripWaxy, waterproof strip in cell walls at endodermis
  43. 43What are mesophyll cellsType of leaf cell
  44. 44What is the affect of air bubbles in the xylemThey can block the column of water, preventing water from reaching the cells
  45. 45What is partial pressure of oxygen pO2Measure of oxygen concentration, the higher the concentration of dissolved oxygen in cells = higher partial pressure
  46. 46Why do plants need transport systemsNeed water, minerals and sugars to live, and need to get rid of waste substances. Multicellular with small SA:V ratio. If they exchanged substances directly, it would be too slow
  47. 47How does pO2 affect haemoglobin's affinity for oxygenOxygen loads onto hb in a high pO2, oxygen unloads in a low pO2
  48. 48What is ligninSpiralled woody substance in xylem vessels, supporting the xylem walls and allowing flexibility to prevent stem from breaking
  49. 49Where is there a high pO2Alveoli in lungs
  50. 50What are pits in the xylem vesselIn walls where there is no lignin, allowing water and mineral ions to move in/out of vessels to supply other types of cells with water
  51. 51Where is there a low pO2Respiring tissue
  52. 52What is the purpose of having no end walls in xylem vesselsMaking an uninterrupted tube allowing water to pass up through centre easily
  53. 53What does an oxygen dissociation curve showHow saturated hb is with oxygen at a given pO2
  54. 54What are xylem vessels formed ofLong tube like structures formed from vessel elements, dead cells containing no cytoplasm
  55. 55What are dictoyledonous plantsGreen, non-woody plants bushes and trees
  56. 56How is phloem formedFrom cells arranged in tubes, living cells
  57. 57Why are disassociation curves S shaped instead of a straight lineWhen oxygen first binds with hb, it alters it's shape to make it easier for other oxygen molecules to bind. As hb becomes more saturated with oxygen, it's shape makes it harder for other oxygen molecules to join. Steep part of curve is where it's easy for oxygen molecules to join
  58. 58What living cells are in the phloemPhloem fibres, parenchyma, sieve tube elements and companion cells
  59. 59Describe sieve tube elementsJoined end to end to form sieve tubes, sieve plates have holes to allow sugars to pass through, no nucleus, few organelles, thing cytoplasm
  60. 60Describe companion cellsFor every sieve tube element, carry out living functions for themselves and sieve tubes such as providing energy for active transport of sugars
  61. 61Why does fetal haemoglobin have a higher affinity for oxygen than adult haemoglobinFetus' gets oxygen from mother's blood across placenta, by the time it reaches placenta, oxygen saturation has decreased as it has been used up by the mother's body. Placenta has a low pO2, helping oxygen to unload. Curve is to the LEFT of adult hb curve.
  62. 62Are the sugars transported in the phloem whole or dissolvedDissolved
  63. 63What is a single circulatory systemBlood only passes through the heart once for each complete circuit of the body
  64. 64What is a double circulatory systemBlood passes through the heart twice for each complete circuit around the body
  65. 65What is the partial pressure of carbon dioxide pCO2Measure of the concentration of CO2 in a cell
  66. 66What is a closed circulatory system and give an exampleBlood is enclosed in blood vessels - fish
  67. 67How does pCO2 affect disassociation of oxygen from oxyhbHb gives up oxygen more readily in a higher pCO2
  68. 68What is an open circulatory system and give an exampleBlood flows freely in body cavity - insects
  69. 69Name features of the right side of the heartInferior and superior vena cava, pulmonary artery, right ventricle, right atrium, semi lunar valve, tricuspid valve
  70. 70Name features of the left side of the heartAorta, pulmonary vein, left atrium, left ventricle, semi lunar valve, bicuspid valve
  71. 71Outline the bohr effectCO2 in red blood cells converted to carbonic acid by carbonic anahydrase, carbonic acid splits into hydrogen and hydrogencarbonate ions, the increase in hydrogen ions causes oxyhb to unload oxygen so hb can take up hydrogen ions forming haemoglobonic acid
  72. 72What is the purpose of heart valvesPrevent backflow of blood
  73. 73Why is the heart muscle thicker on the leftAs left ventricle pumps blood around the whole body
  74. 74What is the main advantage of the bohr effectTo get more oxygen to respiring tissues
  75. 75What is the word equation for aerobic respirationglucose + oxygen ¬ carbon dioxide + water + energy
  76. 76What is the purpose of coronary arteriesTo supply the heart with an oxygenated blood supply
  77. 77What is hydrostatic pressureWhere blood is under high pressure in arteries due to contraction of ventricle walls
  78. 78Give the brief sequence of the cardiac cycle1. Ventricles relax, atria contract
    2. Ventricles contract, atria relax
    3. Ventricles relax, atria relax
  79. 79What is the SANSino atrial node in wall of right atrium, sending waves of electrical activity over the atrial walls
  80. 80What is the purpose of non-conducting collagen tissue in the heartPrevents the waves of electrical activity from being passed directly from artia - ventricles. Causes delay which allows for the atria to empty before ventricles contract
  81. 81What is the AVNAtrioventriclular node passing waves of electrical activity on to the bundle of HIS
  82. 82What is the bundle of HISGroup of muscle fibres conducting waves to purkyne tissue
  83. 83What is the purkyne tissueCarries waves of electrical activity in walls of ventricles, causing them to contract together from apex upwards
  84. 84What is an elecctrocardiographMachine recording electrical activity of the heart
  85. 85What is an electrocardiogramTrace produced by an electrocardiograph

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A-Levels Biology f211 Flashcards on Exchange and Transport, created by Gemma Bradford on 12/05/2013.
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Gemma Bradford
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