Unit 8 - Transport in plants Flashcards
1
Q
Two tissues used for transportation in plants
A
- Xylem
- Phloem
2
Q
Structure of the xylem
A
- Hollow tubes
- Lignin gives the xylem thick walls for supports
- Long continuous tubes from the root to the leaves
- Lumen has no cytoplasm
- Dead cells - no nucleus
3
Q
Xylem function
A
- Transporting water and dissolved mineral ions from the roots through the stem to the leaves
- Providing support for the plant to keep it upright
4
Q
Phloem structure
A
- Sieve plates and tubes
- Companion cells to give energy for transport
5
Q
Phloem function
A
- Transporting sucrose
- Transporting amino acids
6
Q
Position of xylem and phloem in a plant
A
- Roots
- Stems
- Leaves
- Xylem is on the inside of the vascular bundle, and phloem on the outside
7
Q
Root hair cells
A
- Specialized cells found on surface of plant roots
- Long hair-like structures
- Absorb water and mineral ions from the soil
- Increased surface area leads to increased absorption
8
Q
Path of water in a plant
A
- Soil –> root hair cells on the surface of a root –> root cortex cells inside the root –> xylem vessels from the roots through the stem and into mesophyll cells in the leaf
9
Q
What happens to water in the leaf / transpiration
A
- Evaporation at the surface of the spongy mesophyll cells
- Loss of water vapor by diffusion through the stomata
10
Q
Factors that affect rate of transpiration
A
- Increased temperature increases the rate
- Wind increases the rate of transpiration
11
Q
Transpiration pull
A
- Suction force
- Draws water in the xylem upwards from the roots to the leaves
- Forces of attraction between water molecules causes them to form a continuous column
- Results from evaporation of water from mesophyll cells in leaves
12
Q
Effect of number of stomata in a plant
A
- More stomata leads to more water loss through transpiration
13
Q
Wilting
A
- When the rate of transpiration if greater than the rate the water is absorbed through the root hair cells - reduces turgor pressure and cells become flaccid
14
Q
Translocation
A
The movement of sucrose and amino acids through phloem tissue from a source to a sink
15
Q
Source
A
A region of production in a plant
