exam run through Flashcards
which mycorrhizal types associate with trees, grasses and heathers in north temperate systems?
Ectomycorrhizas
Arbscular endomycorrhizas
Ericoid mycorrhizas
experiment to test phosphorous movement in mycelial networks
uptake of P-32 labelled with/without ectomycorrhizas
productivity of rice per hectare
10 tons/ha
three traits important to conventional rice breeding
disease resistance
drought resistance
heat tolerance … many more
why conventional breeding will not lead to C4 rice production
rice does not seem to have any of the genes for C4
the outer surface of leaves give protection against…
excessive water loss regulates gas exchange attack by insects pathogen attack UV radiation osmotic effects secretes metabolites absorbs nutrients & water
the three major plat nutrients included in inorganic fertilisers
N, P, K
how is nitrate obtained for inorganic fertiliser?
Haber-Bosch process OR natural gas
how is phosphorous obtained for inorganic fertiliser?
phosphate (rock) mining + acid treatment
how is potassium obtained for inorganic fertiliser?
mined potash, K salts extracted
what does nitrogen in fertiliser do for plants?
green leafy growth
what does phosphorous in fertiliser do for plants?
early root & shoot growth
what does potassium in fertiliser do for plants?
flowering, fruiting, transport and hardiness/vigour
what is the typical ratio for combined fertilisers (K, N, P)?
12:12:12
what is linkage mapping?
shows the linear order, spacing and relative recombination frequencies of a series of molecular markers
what does dormancy allow?
plant to wait for more favourable conditions
allows dispersal
avoids transient predators/pathogens
major groups of pests endangering plants
invertebrates e.g. insects
vertebrates e.g. deer
indirect effect of pests on plants
loss of photosynthetic capacity
divert resources to plant defences
create lesions for pathogens to enter by
three types of plant defence
physical/mechanical/morphological
chemical
biological e.g. macaranga trees protected by ants
auxin
promotes & coordinates growth
prevents branching
abscisic acid
promotes seed dormancy
inhibits growth of shoots
causes stomatal closure
cytokinins
promotes cell division
inhibit leaf aging
remove apical dominance
gibberellins
stimulates flowering
promotes seed germinate (in suitable conditions)
ethylene
promotes ripening of fruits
causes of desertification
over-grazing deforestation fire salinization climate change
Australia and salinization
- water table was very low
- irrigation raised water table
- water brought salt to surface
