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Description: Not specified Timestamp: 2013-05-21 16:30:09 +0000
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  1. 1 a i)
  2. A was nucleus
  3. B was chloroplast [2]
  4.  
  5. ii) C was site of aerobic respiration to produce ATP
  6. D process and package of lipids [2]
  7.  
  8.  
  9. b)
  10. Light has a longer wavelength meaning weaker magnification (x1500) and lower resolution (200nm)? Light microscopes can only view general cell features and mitochondria is too small [2]
  11.  
  12.  
  13. c) Compare and contrast
  14. Distinguish different features [2]
  15.  
  16.  
  17.  
  18. 2ai) 0.6:1 show working: SA/Volume [B][2]
  19. [B]
  20. ii) the greater the surface area: volume ratio, the faster the rate of diffusion (or reverse argument). Give examples (uneccesary?) [B][2]
  21. [B]
  22. iii) small surface are a to volume ratio, therefore slow rate of diffusion [B][2]
  23. [B]
  24.  
  25. bi) Lentgh divided by time [B][1]
  26. [B]
  27. ii) length divided by time / 2 [B][1]
  28. [B]
  29.  
  30. C)
  31. Squamous epithelium - very thin allows for short diffusion distance
  32. Large number of alveoli- increase surface are for faster diffusion
  33. Good supply of blood- removal and picking up of o2 so steep concentration gradient of co2 and O2
  34. Good ventilation- refreshment of air mean it cause steep concentration/ diffusion gradient [B][4]
  35. [B]
  36.  
  37. 3ai) mitosis [B][1]
  38. [B]
  39. ii) 4 chromosomes or sister chromatids side by side with centromere attached spindle fibres at equator [B][2]
  40. [B]
  41. iii) -800 to -950 to -1050 and -800 to -1050 [B][2]
  42. [B]
  43. b) Ring of vascular (xylem and phloem) under the bark. Cambium has meristem cells that can undergo mitosis and differentiate (for growth) [B][2]
  44. [B]
  45. C) root of tips [B][1]
  46. [B]
  47. d) multicellular organisms have a small surface area to volume ratio so slower rate of diffusion and greater diffusion distance, animals don't need Lentices as they already have a specialised gas exchange system (confirmation needed) [B][2]
  48. [B]
  49.  
  50. 4a i) Fetal haemoglobin has a higher affinity for oxygen;can absorb or associate with oxygen at lower tension; adult haemoglobin releases oxygen at low tension which the fetal haemoglobin associates with. [B][3]
  51. [B]
  52. ii) Fetal haemoglobin has a higher affinity for oxygen than adult haemoglobin, meaning it can absorb oxygen at low partial pressure. [B][2]
  53. [B]
  54. b) High hydrostatic pressure at the arteriole end of capillary than the tissue fluid; dissolved substances move down the hydrostatic gradient through the tiny holes in capillaries; glucose and oxygen small enough to pass through tiny holes [B][4]
  55. [B]
  56.  
  57. 5a i) Seperate organelles from each other; form vesicles to transport materials (proteins etc); [B][2]
  58. [B]
  59. b) any two of the following components with description and functions: phospholipid bilayer, glycoproteins, channel proteins, carrier proteins, glycolipids or cholesterol [B][5]
  60. [B]
  61.  
  62. ci) phospholipid bilayer [B][1]
  63. [B]
  64.  
  65. ii) proteins [B][1]
  66. [B]
  67.  
  68. iii) either ice pierces membrane when frosted and then thaws causing permeability to increase or proteins denature/not working at cold temperature and permeability explanation [B][2]
  69. [B]
  70.  
  71. 6ai)
  72. Transpiration is loss of water vapour from surface of leaves by evaporation whilst for transpiration stream is a result of transpiration, tension forces water up leaves, cohesion of water molecules due to H bonds form column of water, adhesion of water cause it stick on xylem wall and help the stream of water to rise up [B][3]
  73. [B]
  74.  
  75. b) mean number of stomata-13000
  76. Mean surface are - 0.2
  77. Thickness of cuticle- 8.50 [B][3]
  78. [B]
  79.  
  80. C) complete table( blanks as follows)
  81. Ions/minerals; sucrose; No cross/ end Walls; Lignin;Pits;Plasmodesmata. [B][4]
  82. [B]
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