Water uptake and movement

Question 1

what is the importance of water in plants ?

Answer 1

Water provides the cellular solute for metabolism and cell function

Question 2

What does tugor pressure do in plants ?

Answer 2

Tugor pressure derived from water content of vacuoles generates tugor of cells and gives plant tissue rigidty and architecture

Question 3

How does tugor pressure help young cells ?

Answer 3

Tugor pressure not only confers rigidty on mature plant structures but also drives expansion of young cells during unfolding and expansion of structures such as leaves and flowers

Question 4

Where do root hairs differentate from ?

Answer 4

Differentiate from files of epidermal cells in the differentiation zone

Question 5

how does root hair cells differentiate ?

Answer 5

The hair part of the cell extends by tip growth and is initiated at the lower end of the epidermal cell - the nucleus moves into the hair during development

Question 6

How long do root hairs function for ?

Answer 6

Root hairs are only functional for around 48 hours and then die or the hair is sloughed by the soil

Question 7

where do root hairs get generated from ?

Answer 7

New root hairs are constantly being generated by the differentiation zone as the root extends

Question 8

Where does most water uptake by the entire root system occur ?

Answer 8

in the root hair zone of each root

Question 9

What are 3 functions of root hairs ?

Answer 9

1. Supplement older parts of root system which are becoming inefficient due to suberisation and secondary thickening - these reduce permeability
2. Allow invasion of new areas of soil-important because hydraulic conductivity falls rapidly as soil dries, leading to formation of drying zones around roots
3. Enable penetration of soil particles and soil crevices