Plant tissues, organs and systems CONTINUED Flashcards
What are the main roles of plant stems and roots
to transport substances around the plant
What are the two main types of transport systems in plants?
Xylem and Phloem
What does the xylem transport?
Water and minerals
What does the phloem transport?
Sugars and amino acids dissolved in water
How is the xylem formed in the root?
central column, solid support
How are transport tissues of the xylem and phloem grouped?
In vascular bundles
How are leaves adapted for gas exchange and photosynthesis?
Large surface area, thin flattened blade, air spaces between cells, vascular tissue in the midrib and veins
How does a large surface area aid gas exchange and photosynthesis?
For maximum absorption of light; for optimum absorption of carbon dioxide
How does a thin flattened blade aid gas exchange and photosynthesis?
So that water and gases have a limited distance to diffuse
Why are there air spaces between cells vascular tissue in the midrib and veins?
for the diffusion of gases
How are the lungs adapted?
Aveoli are made up of very thin cells for a shortened difussion pathway
Meaning increased the rate at which CO2 and O2 can diffuse
Very large surface area
Walls are moist which allows gases to dissolve(increased rate of diffusion)
Substances moved by active transport?
Mineral ions + glucose molecules
Substances moved by diffusion?
Carbon dioxide, oxygen, food substances, wastes
How does temperature effect the rate of transpiration?
Increased molecular movement (more energy) more water evaporated off the leaf
rate of diffusion of water molecules from the leaf is increased
(increased rate)
How does light intensity effect the rate of transpiration?
Increases the rate of photosynthesis; stomata open so that water diffuses out of the leaf
(increase rate)
