5.3 The cholera bacterium can survive in the small intestine and the large intestine. The bacterium releases a toxin that interacts with receptors on the surface of cells. Fig. 5.3 shows the effect of the toxin. The arrows indicate the direction of movement.     Right-click on the blue button to open Fig. 5.3       5.3.1 State the name of ion X. (1)

5.2 Fig. 5.2 shows a drawing of a cell from the lining of the small intestine. The lumen is the space inside the intestine where food is digested.     Right-click on the blue button to open Fig. 5.2       5.2.1 State the names of the three labelled structures in Fig. 5.2 and describe the role of each structure in the intestinal cell. (6)

3. One of the characteristics of living organisms is sensitivity   3.1 Define the term sensitivity. (2)

1.1 Identify the structures labelled A, B and C in Fig. 1.1. (3)      

3.3.3 Another group of rats was given an injection that did not contain adrenaline. These rats were given food after 2 hours of monitoring. Predict the changes to blood glucose concentration in this group of rats and explain where you will draw the new line to explain your prediction on the graph in Fig. 3.1. (USE DATA TO BE SPECIFIC IN YOUR EXPLANATION) (2)

  TOTAL QUESTION 3

  TOTAL QUESTION 5

6.1.1 State one structural feature of xylem vessels and explain how this is related to the function of water transport. (2)   Feature Explanation    

  QUESTION 5  

39.    The most rapid “saltitory” propagation or “hopping” of an action potential (“nerve impulse”) down an axon occurs only in what type of neurons? a.    myelinated type A and non-myelinated type C neuronsb.    unmyelinated and myelinated type A and B neuronsc.    type C neurons onlyd.    type B neurons onlye.    myelinated type A neurons only