58. (i) 46/23 1 (ii) mitosis; R any possible confusion with meiosis 1 [2] 59. (a) (i) 5:1; 1 (ii) 7 [× smaller]/AW; 1 (b) 0.5; 1 (c) surface area relative to volume too small/AW; diffusion too slow/AW; idea of speed needed distance too great/some cells deep in body/not all cells in contact with environment/AW; R large if unqualified insufficient/AW, oxygen/(named) nutrient, supplied/(named) waste removed; idea of linking (named) areas; look for ‘from…’ ‘to…’ with an implication of organs, not just ‘all over body’ (may be,) more (metabolically) active/AW/, homoiothermic; R just ‘need more energy’ 3 max [6] 60. (i) alveolus/alveolar air, sac/space; A alveoli/air sac A squamous epithelium 1 (ii) large surface area to volume (ratio)/AW; R large area unqualified thin/one cell thick, wall/short diffusion distance/AW; A appropriate figures for width squamous epithelium; permeable; blood supply, qualified; elastic tissue/recoil (after expansion); surfactant; 3 max error carried forward – mark (ii) independently. E.g. candidates who put ‘capillary’ in (i) – could still get points 1 to 4 in (ii) [4] 61. H; C/G; A either or both E; I; D; F; 6 [6]
62. J name neutrophil/phagocyte; A polymorph/granulocyte/eosinophil R monocyte/macrophage/basophile function phagocytosis/engulfing/AW; K name lymphocyte/agranulocyte; A any named lymphocyte, plus correct role function produce/release, antibodies; error carried forward if white cells wrongly named, credit function related to given cell if no names given – credit correct functions for J/K if erythrocyte given, score 0 4 [4] 63. 1 haemoglobin/haem, carries oxygen/AW; 2 detail of no. of oxygen molecules carried; 3 small size/large SA:V ratio, so haemoglobin never far from cell surface/AW; 4 flexible/elastic/stretchy/changes shape/AW; 5 small size/‘stretchiness’/AW, allows red cells to, fit/squeeze, into capillaries; 6 biconcave/AW [A ‘dimpled’], gives, increased/AW, surface area relative to volume (for diffusion); 7 no nucleus to maximise room for, haemoglobin/oxygen/AW; 8 contain carbonic anhydrase; 9 describe, the reaction catalysed by carbonic anhydrase/role in maintenance of diffusion gradient/AW; 10 transport of carbon dioxide as carbamino-haemoglobin/CO2 combines with Hb; 11 ref buffering effect; 12 AVP; e.g. further detail of oxygen carriage variable oxidation state of Fe idea that small size allows them to be close to tissue or cells lack of, other/named, named organelles, also increases room for Hb/O2 max 6 QWC – legible text with accurate spelling, punctuation and grammar; 1 [7] 64. (i) potometer; R ‘transpirometer’ 1
S5 ref to diffusion of, oxygen / carbon dioxide / gases ; S6 (blood carries) oxygen to tissues ; S7 haemoglobin transports oxygen ; S8 both move medium over gas exchange surface ; S9 AVP ; 7 max QWC – legible text with accurate spelling, punctuation and grammar ; 1 [10] 110. mark two columns separately first. If letter and part of cell both incorrect, look to see if the part of the cell corresponds to this letter. If so, allow 1 mark ecf function part of cell controls activities of the cell nucleus A carries out aerobic respiration mitochondrion / mitochondria; D; attaches to mRNA in protein synthesis ribosome(s) / rough ER / RER; C; produces secretory vesicles B; contains digestive enzymes lysosome(s); E; 8 [8] 111. (i) long; thin cell wall; lack of, waterproof / cuticle; large surface area; NOT if cilia / villi / microvilli / tails / etc present in large numbers; (membrane) proteins / carriers / channels / aquaporins; many mitochondria; AVP; (adaptation of part of the cell) 1 max (ii) if candidate a list or a choice, all must be correct active transport / diffusion / facilitated diffusion / described; A pinocytosis NOT passive transport / osmosis / bulk transport 1 (iii) lower water potential inside / ora; movement, down water potential gradient / from high Ψ to low Ψ; through, channel proteins / partially permeable membrane / aquaporins / AW; walls freely permeable;