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48 Cards in this Set
- Front
- Back
essential nutrient
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required for a plant to grow from a seed and complete its life cycle |
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macronutrients
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elements required by plants in large amounts |
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micronutrients
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elements required by plants in small amounts
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symptoms of mineral deficiencies depend on: |
its mobility within the plant |
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deficiencies of mobile nutrients appear in older organs
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deficiencies of immobile nutrients affects young parts |
first b/c older tissues may have adequate reserves |
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what are the most common deficiencies |
N, K, P
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soil |
living organisms may accelerate the process once they become established |
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horizons |
distinct soil layers |
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topsoil |
mixture of decomposing rock of varying texture, living organisms, and humus |
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earthworms bacteria |
alter soil composition |
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soil contains |
bacteria fungi algae, protists insects earthworms nematodes and plant roots |
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humus
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builds a crumbly soil that retains water but is still porous for good root aeration acts as a reservoir for mineral nutrients |
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good soil management is necessary to: |
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agriculture is: |
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who uses more water than natural vegetation |
crops |
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3 important aspects of soil management |
fertilizers irrigation erosion prevention |
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Fertilizers |
enriched in n p k |
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organic fertilizers are |
manure fishmeal and compost |
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release minerals |
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excess minerals from chemical fertilizers may be |
leached from soil and may pollute streams and lakes |
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irrigation
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availability of water limits plant growth more than mineral deficiency |
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problems of irrigating arid land |
can gradually make soil salty and completely infertile |
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solutions for irrigating arid lands |
developments of plant varieties that require less water or can tolerate more salinity |
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erosion
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measures to prevent erosion losses |
terracing hillsides help prevent water erosion planting alfalfa and wheat provide good ground cover and protection |
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plants require: |
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plants cant use |
nitrogen in gaseous form
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to be assimilated by plants,
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nitrogen must be in the form of ammonium or nitrate |
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nitrate is produced in soil by |
nitrifying bacteria that oxidize ammonium |
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other species of nitrogen-fixing bacteria |
live symbiotically in plant roots |
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rhizobia
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symbiotic soil bacteria |
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what is a routine agricultural practice |
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rhizosphere
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the soil layer that surrounds roots |
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mycorrhizae |
fungus roots |
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relationship b/w Mycorrhizae fungi w/plant roots |
help increase the uptake of minerals and water by the roots |
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parasitic plants
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only supplement nutrition by using haustoria to obtain xylem sap from their host plant mistletoe have lost photosynthesis entirely, drawing all nutrients from the host plant by tapping into the phloem dobber |
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epiphytes |
nourish themselves from water and minerals absorbed by rain Spanish moss staghorn ferns |
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carnivorous plants |
live in habitats with poor soil conditions are photosynthetic but obtain N and minerals by killing and digesting insects insect traps evolve by modification of leaves and are usually equipped with glands that secrete digestive juices. |
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most of the mass of organic material of a plant comes from
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carbon dioxide |
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micronutrients are needed in very small amounts because
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most serve mainly as cofactors |
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mycorrhizae enhance plant nutrition mainly by |
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epiphytes are
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plants that grow on other plants |
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some of the problems associated with intense irrigation include all but |
over fertilization |
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a mineral deficiency is likely to affect older leaves more than younger leaves if
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the mineral is very mobile within the plant |
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we would expect the greatest differences in plant health b/w 2 groups of plants of the same species, one group with mycorrhizae and one group without mycorrhizae in an environment
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in which the soil is relatively deficient in mineral nutrients |
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2 groups of tomatoes grown in a lab one with humus one without. the leaves of the one with out humus were yellowish compared to the one with hummus. Best explanation is
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the humus contained minerals such as magnesium and iron needed for the synthesis of chlorophyll
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the specific relationship b/w a legume and its mutualistic Rhizobium strain probably depends on
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specific recognition b/w the chemical signals and signal receptors of the rhizobium strain and legume species |