<ul><li>Blood cells </li></ul>1. Compare the structure of white and red blood cells. [3 marks] WBC RBC made in bone marrow from stem cells source made in bone marrow from stem cells irregular with lots of extensions shape ALL are biconcave disc (no variation) has nucleus (and is long) nucleus RBC has no nucleus (loses nucleus before it enters blood) WBC has no Hb molecules inside hemoglobin RBC has many Hb molecules inside
2. Compare the function of white and red blood cells. [3 marks] leukocyte (trait) erythrocyte travels in blood movement travels in blood immune response purpose transport oxygen leukocyte moves in blood vessels and between cells and in lymph system location of movement erythrocyte move in blood only leukocyte phagocytozes (eats) bacteria phagocytosis erythrocyte does not do any phagocytosis
3. Describe one structure to function relationship in white blood cells. [3 marks] name describe structure indicate function The nucleus of the leukocyte... is long and narrow... to let the leukocyte slip between cells, in narrow gaps. The leukocyte has a cell membrane... which is flexible and can be extended and folded... so that the leukocyte can “engulf” bacteria (and then digest them) Leukocytes contain “granules”... which are vesicles filled with enzymes and chemicals... that digest or breakdown bacteria
4. Describe one structure to function relationship in red blood cells. [3 marks] name describe structure indicate function The erythrocyte’s shape... is biconcave disc... which provides maximum diffusion rate into cell with maximum volume Erythrocyte’s shape ... is circular and smooth ... so it glides through small openings without getting stuck or jammed. Erythrocytes contain hemoglobin which is a protein that has iron atoms in it ... and this protein/Fe complex binds oxygen to carry oxygen from lungs to cells.