The increase of which gases contributes to an enhanced greenhouse effect?

8.3.1 State that water is transported from the roots to leaves through the xylem vessels

8.3.2 Define transpiration as loss of water vapour from plant leaves by evaporation of water at the surfaces of the mesophyll cells followed by diffusion of water vapour through the stomata

8.3.3 Investigate and describe the effects of variation of temperature and humidity on transpiration rate

8.3.4 Explain how water vapour loss is related to the large surface area of cell surfaces, interconnecting air spaces and stomata

8.3.5 Explain the mechanism by which water moves upwards in the xylem in terms of a transpiration pull that draws up a column of water molecules, held together by cohesion

8.3.6 Explain how and why wilting occurs

8.3.7 Explain the effects of variation of temperature and humidity on transpiration rate