Grace Bentley 3.1 Biology
Aim: To investigate the effects of light intensity on duck weed
Intro: Duck weed (botanically known as lemmnaceae) is a stem less, aquatic flowering plant it is small and free floating and grows on the surface of still or slow moving fresh water in carpet –like groups around the globe it is moved around by the water currents flow or other wild life. Duckweed is able to grow in the most trying condition with their ability to lay dormant in forests and survive on the surface of mud and droughts. The growth of these high protein plants can be very rapid if held in the right conditions. The mesophyll cells containing chloroplast are on the top of the plant giving them their bright green colour because the chloroplast is on the top of the plant it means that it is directly exposed to the sun light one of duck weed favoured conditions this allows the duckweed can absorb the maximum of sun light . Light intensity is a very important in insuring successful growth in duck weed if the light intensity is to low the plant wont bud as rapidly and vice versa so we now know that duck weed needs light to grow but how much does it need or how little this is why I am testing the effects of light intensity on duck weed. The roots are also a very important part of the plant, absorbing the nutrients and water through the cell membrane. This travelling of water through the semi-permeable membrane is called osmosis. Osmosis is the special case of diffusion involving water molecules. Water molecules move from areas of high water concentration to areas of low water concentration through a selectively permeable membrane.But not only do the roots absorb nutrients but also the total surface that is under the water including the leaves. The leaves are also where photosynthesis takes place.
Carbon dioxide and light and water is used...
Please join StudyMode to read the full document