Lecture 25. Plant Nutrition and Digestion Flashcards
What does the endodermis possess ?
A substance that prevents movement of water in cell wall
What transports ions ?
A layer of cells that act as scavenger cells
What are the controlled nutrient supply systems ?
- Aeroponics
- Hydroponics
- Aquaponics
- Fertiliser application
What is an aeroponic system ?
The roots are not embedded, nutrients are delivered by a fine mist
What is the advantage of the aeroponic system ?
Easy to keep disease free
What is an aquaponic system ?
Plant roots are in an tank of fish
What provided the nutrients in an aquaponic system ?
Fish provide the nitrogenous waste which is used for plant growth
What are serpentine soils ?
Soils which have high concentrations of heavy metals that occur naturally or through acid deposition
What are serpentine soils characterised by ?
High concentrations of Mg, Fe, Ni, Co, Mn and Cd
What are serpentine soils derived from ?
Weathering of ultramatic soils having high concentrations of ferromagnesium minerals
What have some non-photosynthetic plants evolved to do ?
To obtain their nutrients and organic carbon by growing in or on other plants
Other than parasitism, how have non-photosynthetic plants evolved to gain nutrients ?
Carnivory
What are the three orders of flowering plants where parasitic plants are found ?
- Magnoliidae
- Rosidae
- Asteridae
What are holoparasites ?
Plants that are completely parasitic on other plants and have virtually have no chlorophyll
What are hemiparasites ?
Plants that are parasitic under natural conditions and are also photosynthetic to some degree
What is mistletoe an example of ?
Holo and hemi parasites
How do mistletoe grow ?
As epiphytic parasites on the branches of trees and shrubs
What do mistletoe do to obtain their food ?
The roots grow into and connect with their hosts vascular tissue, from which they derive water and mineral nutrients but not usually organic substances
What is the process by which root moves along a branch ?
Thigmotropism
What happens when the root encounters an irregularity called ?
A swelling called a holdfast forms
What binds the holdfast to the bark ?
A cementing substance
What forms to penetrate into the cortex of the host ?
A wedge shaped structure
What happens once the parasite is established in the hosts cortex ?
An intimate connection forms between the phloem and xylem cells off the mistletoe and the phloem and xylem cells of the host
What does the dwarf mistletoe do to reproduce ?
Employs a pressurised water pump to shoot its seeds up to a distance of 20m
