Transport in Plants Flashcards
What are the functions of xylem?
Xylem transports water and mineral ions and provides support for the plant’s overall structure.
What are the functions of phloem?
Phloem transports sucrose and amino acids from the source to the sink and vice versa.
What are the adaptations of xylem?
Thick walls with lignin (dead cells)
No cell contents
Cells joined end to end with no cross walls to form a continuous tube
How do root hair cells absorb water?
Root hair cells absorb water by osmosis due to their large surface area, which increases water uptake from the soil.
What is the pathway of water through the plant?
Water moves from root hair cells to root cortex cells, then to xylem, and finally to mesophyll cells in the leaf.
What is transpiration?
Transpiration is the loss of water vapour from the leaves through the stomata.
How does water move during transpiration?
Water evaporates from the mesophyll cells, moves into air spaces, and diffuses out of the leaves through the stomata.
What causes wilting in plants?
Wilting occurs when water loss exceeds water uptake, causing cells to become flaccid and tissues to become limp.
What factors affect the rate of transpiration?
-Temperature: Higher temperatures increase evaporation and diffusion rates.
-Humidity: Low humidity increases transpiration, while high humidity decreases it.
-Wind speed: Wind increases transpiration by removing water vapour and maintaining a steep concentration gradient.
What is translocation in plants?
Translocation is the movement of sucrose and amino acids in the phloem from the source (where they are produced) to the sink (where they are used or stored).
What are sources and sinks in plant translocation?
Sources: Parts of the plant that release sucrose or amino acids.
Sinks: Parts of the plant that use or store sucrose or amino acids.
How does water move through the root to the stem and leaf?
Water enters the root hair cells by osmosis, travels through root cortex cells to the xylem, and moves up the stem to the mesophyll cells in the leaves.
