Biology independent investigation, Ecology

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1.01-Focus Question – Will higher concentrations of sodium fluoride reduce the dry root mass and the dry mass of Phaseolus  vulgaris (green bean)?

1.0.2- Hypothesis – The dry mass and dry root mass of Phaseolus  vulgaris will be reduced in higher concentration of sodium fluoride.

.1.0.3- Theory – Sodium fluoride is a ionic compound between a single Na atom and a single F atom. This bond through a ionic bond to form Na-F. Sodium fluoride exists naturally is soil in concentrations from 0.5ppm to 1.5ppm. 8kg of sodium fluoride is lethal to a 70kg human (Unknown 2008). Technically sodium fluoride is a salt and therefore it is possible that it could affect plant growth. Ionic salts basically clog out water intake line in plant roots. It inhibits the plants ability to absorb water and nutrients from the soil. Therefore the plant cannot before photosynthesis as effectively. Photosynthesis is vital to the production of plant energy (starch). Without this energy the plant’s growth would be slower as it is vital for the production of new cells (R. Perry). Therefore if a plant is placed in an environment with an excess of an ionic compound such as Na-F it is highly possible that he plant will die. There are some exceptions to this however. Many plants such as mangroves thrive is high salt environments as they root systems allow them to absorb salts as nutrients. This however is not the case with the most crops. Crops normally have very thing stalks and have soft root systems. This makes them highly susceptible to many biotic such as weather and biotic factors such as pests. The state of the water itself is no exception. If crops where to be placed in high salt environment it is highly possible that they would die or not grow at all as the root systems would not be able to absorb nutrients and water (Australian Government 2008). Also if an area is made to be highly saline through treatment or removal of salt absorbing trees it is possible that he area will be lost forever as the salinity become so high that indigenous plants will no longer grow in that area. Many cities and councils in Australia have recently adopted a system in which Na-F will be added into water supplies as it will aid in dental hygiene. This Na-F is existent in trace amount and is very safe for human consumption. When human consume Na-F the compound will merely be absorbed and eventually excreted. However the same water that is used for drinking will also possible are used for the watering of plants. The soil however cannot “remove” the Na-F like humans can. Over time it is possible that the level of Na-F could build-up to such as level that plants in the area begin to die. On a side note when rain arrives, it will wash the Na-F in to rivers and eventually back into human water supplies, which could endanger human life. One of the most reliable ways to measure the development of a plant is to measure is dry weight. This means that water will not be a contributing factor to the weight and the only factor will be the actually plant mass and therefore the amount of growth.  Another factor that is indicative of a healthy plant is the mass of the root system which can be measured by separating the root system from the seedling.  (D, Timmers 2009)

  1. Experimental setup

1.1.1- Variables – (table 1)

1.1.2-Control Used for Comparison – Distilled water as it is pure and will not have any fluorine present

1.1.3- Apparatus and Materials (Table 2)

Materials-

1.1.4Safety Aspects – (TABLE 3)

1.1.5 Protocol and Protocol Diagram – (diagram 1 and 2)

How to do a dilution series (diagram 1)

Stock              90mls of pure water                20mls of pure water    

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Solution

100mls

1mg                      0.1mg                               0.08mg        

How to acquire qualitative data (Diagram 2)

        

1.1.6 Experimental setup-(Diagram 3)

1.1.7 Procedure –

Preparation of solutions

  1. Draw 100mls of stock solution and place in a
  2. For 10ppm  concentration draw 10ml of stock solution and place in 90ml of distilled water
  3. For 8ppm concentration draw 80ml of 0.1m solution and place ...

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