IGCSE Biology

Explain the effects on the rate of transpiration of varying the following factors: temperature, wind speed and humidity

Explain how water vapour loss is related to: the large internal surface area provided by the interconnecting air spaces between mesophyll cells and the size and number of stomata

Investigate and describe the effects of variation of temperature and wind speed on transpiration rate

State that water evaporates from the surfaces of the mesophyll cells into the air spaces and then diffuses out of the leaves through the stomata as water vapour

Describe transpiration as the loss of water vapour from leaves

Investigate, using a suitable stain, the pathway of water through the above-ground parts of a plant

Outline the pathway taken by water through the root, stem and leaf as: root hair cells, root cortex cells, xylem, mesophyll cells

Identify in diagrams and images the position of xylem and phloem as seen in sections of roots, stems and leaves of non-woody dicotyledonous plants

State the functions of xylem and phloem: (a) xylem – transport of water and mineral ions, and support (b) phloem – transport of sucrose and amino acids

Describe the roles of capillaries and lacteals in villi