Biology · Form and function

B3.2 — Transport

Biology · SL / HL · syllabus-mapped notes

1. B3.2.1

   Adaptations of capillaries for exchange of materials between blood and the internal or external environment

   Explain three capillary adaptations: large surface area, thin walls, and fenestrations.

2. B3.2.2

   Structure of arteries and veins

   Distinguish arteries from veins in micrographs by wall structure and thickness relative to the lumen.

3. B3.2.3

   Adaptations of arteries for the transport of blood away from the heart

   Explain how muscle and elastic tissue let arteries withstand and maintain high blood pressure.

4. B3.2.4

   Measurement of pulse rates

   Determine heart rate from the carotid or radial pulse, and compare with a digital method.

5. B3.2.5

   Adaptations of veins for the return of blood to the heart

   Explain two vein adaptations: valves preventing backflow, and a wall flexible enough to be compressed.

6. B3.2.6

   Causes and consequences of occlusion of the coronary arteries

   Explain the causes and consequences of coronary occlusion, and evaluate the epidemiological evidence.

7. B3.2.7

   Transport of water from roots to leaves during transpiration

   Explain how transpiration generates tension in xylem, and how cohesion keeps the column continuous.

8. B3.2.8

   Adaptations of xylem vessels for transport of water

   Explain four xylem adaptations: no contents, open end walls, lignified walls and pits.

9. B3.2.9

   Distribution of tissues in a transverse section of the stem of a dicotyledonous plant

   Draw a plan diagram of a dicot stem, annotated with the function of each tissue.

10. B3.2.10

    Distribution of tissues in a transverse section of the root of a dicotyledonous plant

    Draw a plan diagram of a dicot root, identifying the vascular tissue, cortex and epidermis.

11. B3.2.11

    Release and reuptake of tissue fluid in capillaries

    Explain how pressure filtration forms tissue fluid near arterioles and reabsorbs it near venules.

12. B3.2.12

    Exchange of substances between tissue fluid and cells in tissues

    Compare plasma and tissue fluid, and explain how cells exchange substances with it.

13. B3.2.13

    Drainage of excess tissue fluid into lymph ducts

    Describe how lymph ducts drain excess tissue fluid and return it to the blood.

14. B3.2.14

    Differences between the single circulation of bony fish and the double circulation of mammals

    Contrast the single circulation of bony fish with the double circulation of mammals.

15. B3.2.15

    Adaptations of the mammalian heart for delivering pressurized blood to the arteries

    Explain the form-function adaptations of the heart, and trace the flow from named veins to arteries.

16. B3.2.16

    Stages in the cardiac cycle

    Explain the cardiac cycle following the sinoatrial node, and interpret blood pressure data.

17. B3.2.17

    Generation of root pressure in xylem vessels by active transport of mineral ions

    Explain how active transport of mineral ions generates root pressure when transpiration is insufficient.

18. B3.2.18

    Adaptations of phloem sieve tubes and companion cells for translocation of sap

    Explain phloem adaptations, and how pressure differences drive sap from sources to sinks.