A small mountain lake has aquatic plants growing underwater on the lake bed. Shortly after heavy rainfall the mud on the lake bed becomes churned up and the water level rises. Why does this cause the rate of photosynthesis of these plants to fall?

Describe the significance of each of the following features of a dicotyledonous leaf in terms of the process named: t…

Which row shows what happens in photosynthesis?

During a sunny day, which substance is excreted from a leaf?

Areas of tropical rainforests are often cut down and cleared. After cutting down the trees, the areas are normally bu…

Which processes involve parts of the carpel of a flower?

What identifies a cause, a symptom and a treatment for syphilis in humans?