Plant structure and functions Flashcards
PHOTOSYNTHESIS equation
carbon dioxide + water > glucose + oxygen
6CO^2 + 6H^2O > C^6H^120^6 + 60^2
How to test for starch?
Test with iodine. Blue > black
Is photosynthesis endo or exothermic?
Endothermic reaction > energy is taken in during the reaction
What affects the rate of photosynthesis?
Light intensity, concentration of carbon dioxide levels, temperature
Why do root hair cells have a large surface area?
For absorbing water and mineral ions from the soil
Is concentration of mineral ions higher or lower in root hair cells?
the concentration of mineral ions is usally HIGHER in cell than soil around them, mineral ions are absorbed by active transport and water is absorbed by osmosis
Features of leaves
- large surface area to absorb sunlight
- lots of chloroplasts containing chlorophyll found in palisade layer for maximum exposure to sunlight
- waxy surface helps maintain water
What are PHLOEM TUBES?
made of columns of elongated living cells with small pores in the end walls to allow stuff to flow through
What do PHLOEM TUBES transport?
transport food substances (mainly sucrose) made in the leaves to the rest of the plant for immediate use or for storage > TRANSLOCATION requiring energy from respiration transport goes in both directions
What are XYLEM TUBES?
dead cells joined end to end with no end walls between them and a hole down th emiddle, strengthned by lignin.
What do XYLEM CELLS carry?
Water and mineral ions from the roots to the stem and leaves, movement of water is called TRANSPIRATION STREAM.
When stomata cells are open …
Guard cells are turgid/ swollen with water
When stomata cells are closed…
Guard cells are flaccid/ low on water and limp
What affects transpiration rate?
- light intensity
- tempreture
- air flow
