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Subject: excretory system
Replies: 2 Views: 466
danisco6 28.03.11 - 01:47pm
how does plant excrete *
fatzak 29.03.11 - 01:06pm
How do plants get rid of their waste ?
Plant cells have large vacuoles, and these can be used for either storage of useful compounds, or the storage of waste substances - often accumulating at concentrations that lead to crystal formation in the vacuole.
Plants can also store the waste in organs that are destined to fall off (like autumn leaves) or die off (like the leaves and stalk of a bluebell which is dying back in the summer,leaving the bulb underground.
Some plants will actively secrete waste compounds into the soil, occasionally using them as chemical weapons against other competing plants!
Oxygen can be looked upon as a waste product of photosynthesis and Carbon dioxide a waste product of respiration; water is a waste product of both. You know how the gases are lost from leaves - don't you? Water will be lost through transpiration or just used for maintaining turgor in cells.
Some trees deposit strange chemicals in their branches and trunks, especially in old xylem which is probably no longer used for water transport (trees like Yew have heart-wood, Ebony produces very black wood at its centre). Perhaps these are waste materials. You could also think about why gardeners find rotted autumn leaves a good source of minerals (as well as organic matter). Or you could think why there is so much ash left when leaves are burned in a bonfire (same question really). *
danisco6 29.03.11 - 07:30pm
ys das de answ *
