#B2.2a
explain the need for exchange surfaces and a transport system in multicellular organisms in terms of surface area : volume ratio
surface area, volume and diffusion distances
#B2.2b
describe some of the substances transported into and out of a range of organisms in terms of the requirements of those organisms
oxygen, carbon dioxide, water, dissolved food molecules, mineral ions and urea
#B2.2c
describe the human circulatory system
the relationship with the gaseous exchange system, the need for a double circulatory system in mammals and the arrangement of vessels
#B2.2d
explain how the structure of the heart and the blood vessels are adapted to their functions
the structure of the mammalian heart with reference to valves, chambers, cardiac muscle and the structure of blood vessels with reference to thickness of walls, diameter of lumen, presence of valves
#B2.2e
explain how red blood cells and plasma are adapted to their transport functions in the blood
#B2.2f
explain how water and mineral ions are taken up by plants, relating the structure of the root hair cells to their function
#B2.2g
describe the processes of transpiration and translocation
the structure and function of the stomata
#B2.2h
explain how the structure of the xylem and phloem are adapted to their functions in the plant
#B2.2i
explain the effect of a variety of environmental factors on the rate of water uptake by a plant
light intensity, air movement, and temperature
#B2.2j
describe how a simple potometer can be used to investigate factors that affect the rate of water uptake