Explain what would happen to red blood cells if they are placed in a concentrated salt solution. (Answered) Why is oxygen important in the process of active transport in cells? (Answered) How do the following factors affect the rate of diffusion?
(i) Diffusion gradient
(ii) Surface area to volume ratio.
(iii) Temperature (Answered) Outline three roles of active transport? (Answered) State the importance of osmosis in plants. (Answered) An experiment was set up as shown below.
The setup was left for 30 minutes.
(a) State the expected results
(b) Explain your answer in (a) above (Answered) Distinguish between diffusion and osmosis (Answered) The diagram below show a red blood cells that was subjected to a certain treatment.
Account for the shape of the cell at the end of the experiment (Answered) A freshly obtained dandelion stem measuring 5cm long was split lengthwise to obtain two similar pieces. The pieces were placed in solutions of different concentrations in petri dishes (L1 and L2) for 20 minutes. The appearance after 20 minutes is as shown
(a) Account for the appearance of the pieces in solution L1 and L2
(b) State the significance of the biological process involved in the (Answered) Distinguish between diffusion and active transport (Answered) State one role that is played by osmosis in Plants (Answered) State one role that is played by osmosis in animals (Answered) Name the type of movement that occurs within a plant cell (Answered) Distinguish between haemolysis and plasmolysis (Answered) The diagram below show an experimental set-up to investigate a certain process in a plant tissue.
Explain the results obtained after 30 minutes. (Answered) In an investigation a student extracted three pairs of pawpaw cylinders using a cork borer. The cylinders were cut back to 50mm length and placed in a beaker containing a solution. The results after 40 minutes were as shown in the table below.
(a) Account for the results in the table above.
(b) What would be a suitable control set up for the investigation? (Answered) State three factors that affect the rate of diffusion. (Answered) What is meant by term Wilting? (Answered) Explain how an increase in temperature affects the rate of active of transport. (Answered) The diagram below represents a cell as seen under an electron microscope.
(a) Based on the diagram, state whether it represents an animal cell or plant cell
(b) Give two reasons for your answer in (a) above (Answered) Why is the palisade layer a tissue? (Answered) Describe how turgor pressure builds up. (Answered) State two ways in which osmosis is significant to plants (Answered) The diagram below shows a set up for an experiment to demonstrate a certain physiological process
(a) What nature of solution is represented by 20% sugar solution?
(b) Explain the observation made on the set up after one hour. (Answered) Explain two roles of diffusion in human beings. (Answered) What is meant by each of the following terms?
(i) Crenated cell
(ii) Flaccid cell (Answered) The table provided shows the concentration of sodium and iodine in sea water and cell sap of a plant.
(a) (i) Name the process through which the plant
cell take up sodium ions.
(ii) Give a reason for your answer in (a) (i) above.
(b) If the plant was sprayed with a chemical that inhibit respiration.
(i) Which of the two ions uptake will be affected?
(ii) Give a reason for your answer in (b) (i) (Answered) Students set up an experiment as illustrated below.
(a) Name the physiological process that resulted in the observation made after 30 minutes.
(b) State the importance of the physiological process investigated in plants.
(c) Explain the observation made after 30 minutes. (Answered) The set up below illustrate a certain physiological process.
(a) (i) Name the physiological process
(ii) Give two examples of the process named in (a) (i) above in plants.
(b) State two ways by which the movement of dye molecules in the set up would be slowed down. (Answered)
