This page contains images and other resources related to plants, with an explanation of each.
Transpiration Pull, Cohesive force etc (Animation)
The Flash animation below depicts how Transpiration pull & Cohesive force helps in carrying the water upwards in tall trees. (please have your speakers turned on!) I have not created this, but am not sure of its source. If any of you find the source, please let me know so I can give due credit here! :)
Variegated Leaves
Heard of variegated leaves before?? You better have...if you have done Photosynthesis!! See how colourful the leaves are!! The leaves are enough to attract the insects for pollination...the flowers are pretty insignificant (more 'insignificant' than 'pretty' actually!) These leaves are called 'variegated' as they have a variety of colours - indicating that they contain chlorophyll only in some parts of the leaf! That is why they are used in experiments to prove that chlorophyll is necessary for photosynthesis. The first picture is of a plant called Croton, and the second one is Coleus.
The Venus Fly Trap
This is one of the interesting insectivorous plants that you would definitely have heard of! Ever wondered why they need to trap insects, when they are green and they can prepare their own food?? Well...that is because they grow in areas where there isn't much nitrogen in the soil. Therefore, they trap insects in order to 'suck out' the nitrogen from these insect's bodies!
What we see in the picture alongside are the modified leaves of this plant that appear like jaws! As soon an insect enters, the cells of the leaf suddenly lose turgidity, thereby causing the "jaws" of the Venus Fly Trap to shut!
Click here to see a video of a Venus Fly Trap in action...with some fantastic narration!
What we see in the picture alongside are the modified leaves of this plant that appear like jaws! As soon an insect enters, the cells of the leaf suddenly lose turgidity, thereby causing the "jaws" of the Venus Fly Trap to shut!
Click here to see a video of a Venus Fly Trap in action...with some fantastic narration!
Chloroplasts
This is a photograph of cells of Elodea (an aquatic plant) taken through a microscope. It shows the chloroplasts within the cells very clearly.
Guard Cells and Stomata
The photos alongside show guard cells and stomata as well as the cells lying next to them along the undersurface of the leaf. Note in images A, B and E, the neighbouring epidermal cells appear like pavement blocks.
(Source: http://www.vcbio.science.ru.nl)
(Source: http://www.vcbio.science.ru.nl)
Starch Test
This depicts a variegated leaf before and after a starch test. Note that the variegated leaf has chlorophyll in the middle and non-chlorophyll regions along the margin. After the starch test, the middle part turns blue-black, indicating that this part has produced starch, while the margin turns brown, indicating that this part did not produce starch. This therefore proves that in the presence of chlorophyll, starch is produced - or in other words, chlorophyll is required for photosynthesis.
The images alongside depict the starch test carried out on a leaf. The aim of the experiment here is to prove that sunlight is required for photosynthesis. Note the blue-black colouration in the areas that produced starch (the areas that were exposed to sunlight) and the brown colouration in the area that did not produce starch (the part that was blocked off from sunlight by the black paper!)
(Source for this and the above image: http://faculty.ntcc.edu/mhearron/photosynthesis.htm)
(Source for this and the above image: http://faculty.ntcc.edu/mhearron/photosynthesis.htm)
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