Castrol operates in a tough competitive world in which winning businesses are those which best understand the needs of the market. Castrol knows that the route to success lies in providing the best products for different segments of the market. One way that the market is segmented is by product category - motor cars, motor cycles, trucks, leisure boats, and aircraft.

31. What is the endosymbiotic hypothesis regarding the origin of mitochondria? What molecular facts support this hypothesis? To which other cellular organelles can the hypothesis also be applied?

32. What are the main components of the cytoskeleton?

33. What are the functions of the cytoskeleton?

34. What are chloroplasts? What is the main function of chloroplasts?

35. What is the molecule responsible for the absorption of light energy during photosynthesis? Where is that molecule located in photosynthetic cells?

36. What colors (of the electromagnetic spectrum) are absorbed by plants? What would happen to photosynthesis if the green light waves that reach a plant were blocked?

37. What path is followed by the energy absorbed by plants to be used in photosynthesis?

38. What substance are plant cell walls made of? Which monomer is this substance made of?

39. What is the function of plant cell walls?

40. What are plant cell vacuoles? What are their functions? What is the covering membrane of vacuoles called?