excretion in plants
TRANSCRIPT
![Page 1: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/1.jpg)
EXCRETION IN PLANTS
![Page 2: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/2.jpg)
IntroductionAnimals are known to excrete wastes and usually have a special set of organs or a system that carries out that function. Do you think flowering plants like these also carry out excretion?
![Page 3: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/3.jpg)
Objectives
You should be able to:
1. give examples of waste substances and how they are excreted
by plants.
2. state the importance of excretion to plants.
3
![Page 4: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/4.jpg)
Salt crystals on the leaf surface of the
Black Mangrove
4
![Page 5: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/5.jpg)
Salt glands on Button mangrove leaf petioles
5
salt gland
![Page 6: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/6.jpg)
What is Excretion?
Excretion in Plants 6
Why carry out excretion?
![Page 7: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/7.jpg)
O2 is excreted from photosynthesis
7
![Page 8: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/8.jpg)
What ‘waste’ from respiration is
excreted?
Glucose + Oxygen Carbon Dioxide + Water + Energy
released and made available
C6H12O6 + 6O2 6CO2 + 6H2O + Energy
This means that oxygen combines with sugars present in cells to
break molecular bonds, thus releasing the energy contained in
those bonds.
The other products of the respiratory reactions are carbon
dioxide and water, which can be excreted if not needed then by
the plant.
Excretion in Plants 8
![Page 9: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/9.jpg)
Guttation - The loss of excess water as liquid drops from
the margins of leaves of herbaceous plants, occurring when root
pressure is high and transpiration is low. The water usually
contains sugars and/or salts.
Excretion in Plants 9
![Page 10: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/10.jpg)
Ornamental plants form Calcium
Oxalate crystals in (leaf) cells for
excretion
Excretion in Plants 10
The cells of these plants
contain Calcium oxalate
crystals which are
eliminated when the leaves
die and fall off.
www.flowersgrowing.com/.../12/diefenbachia.jpg
![Page 11: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/11.jpg)
Calcium Oxalate crystals from Pomegranate
leaf (left) and Tilia sp.
Excretion in Plants 11
Development of the calcium oxalate
crystal in pomegranateCalcium oxalate crystal in Tilia sp.
![Page 12: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/12.jpg)
Water, brought to leaves via veins, is excreted
during transpiration
Excretion in Plants 12
![Page 13: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/13.jpg)
Functions of stomata1. Gas Exchanges and 2. Transpiration
Excretion in Plants 13
Oxygen, Carbon dioxide can diffuse in/out
Water vapour diffuses out.
Guard cell
,
![Page 14: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/14.jpg)
Excretion of gases by diffusion
On woody stems - openings
or pores in the layer of bark
which is impervious to gases
or water. Oxygen and Carbon
Dioxide can diffuse through
lenticels that develop in
the bark.
Excretion in Plants 14
![Page 15: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/15.jpg)
Various wastes are removed during leaf fall
• Waste compounds are often stored in dead heartwood,
bark and leaves which die/fall off.
Excretion in Plants 15
• When chlorophyll breaks
down, other compounds in
leaves give the
characteristic autumn
colors seen just
before leaf fall.
![Page 16: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/16.jpg)
Latex (white) can be excreted from plants
Excretion in Plants 16
![Page 17: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/17.jpg)
Gum oozes out of a branch
Gum
Excretion in Plants 17
![Page 18: Excretion in plants](https://reader031.vdocument.in/reader031/viewer/2022021416/58eed9901a28abef3e8b4589/html5/thumbnails/18.jpg)
Summary• Excretion is the removal from the organism’s body of waste
substances produced during cellular metabolism.
• Plants do not have any set excretory system, so, getting rid of wastes often involves storing the substance (e.g. Calcium Oxalate, tannins) in some plant tissue, passing it out onto leaf surfaces (e.g. salts) or diffusion (e.g. O2, CO2).
• Because salts are so removed, excretion also serves the important function of osmo-regulation which maintains homeostasis.
Excretion in Plants 18