12.5 Transport in Vascular Plants

Question 1

3 stages in the transport of water and nutrients

Answer 1

1. From the soil into the roots
2. From the roots into the stem
3. From the stem to the leaves

Question 2

Transport from soil to roots

Answer 2

• Water and nutrients are found in the soil
• The concentration of water and nutrients in the soil is larger than that of the concentration of water and nutrients in the roots
• Therefore, water and nutrients will flow into the roots
• The movement of water based on pressure/concentration is referred to as osmosis

Question 3

Transport from roots to stem

Answer 3

• As we pump more nutrients and water into the xylem, they increase their concentration
• We must go from high to low pressure!
• This forces water and nutrients up, and is known as an osmotic force, called root pressure
• This is aided by capillary action (the tendency of a liquid to rise or fall based on attractive forces between the molecules)

Question 4

Transport from stem to leaves

Answer 4

• The capillary action and root pressure alone is not enough to get water allllll the way to the top of the plant
• There needs to be help from transpiration
• The evaporation of water through the stomata of plant leaves
• Water has a strong attractive force to it, therefore when it is evaporated, it pulls water molecules along
• Think of water molecules all attached to the same string!

Question 5

Turgor

Answer 5

• a lack of water will dehydrate the plant, and it will wilt
• Plant cells store water (in the vacuole), and once full, exerts a pressure on the cell
• This consistent pressure allows the plant to keep its shape, called turgor

Question 6

Transport of sugar

Answer 6

-Plants use glucose and other sugars as their source of energy
- This can come from two spots:
- Photosynthesis (main source)
- Breaking down carbohydrates in storage organs
- A cell that contains a high concentration of sugars is known as a source of sugar (ex: leaf cell)
- A cell with a low concentration of sugars is known as a sink
- They use up sugar quickly in order for growth!
- Through the phloem, sugar can transport from higher concentrations to lower concentrations