A botanist _____ in 1937, worked out that a four-month-old rye plant had an aggregate root length of about 600km.

The diagram A given below shows a root hair growing through the soil particles. Diagram B is the root hair of an aquatic plant.    

 Name two substances which enter the root hair through part labelled 3

Given below is the diagram of a bean root : 

What term is given to the part marked X? 

What is the function of root hair?

The diagram A given below shows a root hair growing through the soil particles. The diagram B is the root hair of an aquatic plant.    

Account for the different shapes of root hairs in the two diagrams.

Complete the analogy:

Chloroplast: Photosynthesis::Root hair: _____.