(a) State two ways in which the mesophyll layer of the leaf is adapted for photosynthesis (b) In the test for starch in a leaf, why is the leaf boiled in warm alcohol?

List three uses of fibres to plants.

Explain briefly how a large quantity of dead organic materials dumped into a river can be harmful to aquatic life.

Name the physical processes responsible for the following (a) entry of carbon dioxide into the leaf through the stomata (b) entry of soil water into the root hair (c) shrinkage of plant tissue in hypertonic sugar solution

Name the blood vessel that carries digested food to the liver.