Essay on Biology: Water and Surface Area

Submitted By tlatnals
Words: 1144
Pages: 5

This experiment examined the difference between the amount of water loss of the plants under a windy condition and the amount of water loss of those under normal conditions (the control group), thereby testing the effect of the certain environmental variable on the rate of transpiration (the loss of water vapour from leaves and other parts of the plant in the air) of the plants. In this experiment, the six plants (the same type of plant) were being tested and were divided into two groups (three under a wind condition and other three with no environmental factor), than we measured the mass of each plant everyday to obtain the percentage change in mass for each day. This experiment eventually obtained the result that the plants that was exposed to wind had a higher percentage change in mass for each day than the control group had and, thus, had a higher rate of transpiration. Therefore, this experiment concluded that wind increases the movement of water from the leaf surface and the rate of transpiration of plants.

The purpose of the experiment was to find out whether wind cause plants to transpire more or less by determining the rates of transpiration of the plants that are exposed to wind and those that are not and by comparing and contrasting the rates of these plants. Transpiration is the loss of water vapour from leaves and other parts of the plant in the air due to water potential differences and capillary action. Therefore, the rate of transpiration is how quickly the water vapour is being lost from a plant. Transpiration causes lower water potential at the top of the plant and, thus, provides the pull, tension (when moving water up from the root through the xylem in a plant), pulling water up because water always moves from a region of a high water potential to that of a low water potential. In this experiment, wrapping the root of each plant with a plastic bag occurs to prevent the absorption of any water to witness only the water loss. This lab also obtained the surface area of a leaf of each plant, considering the fact that the high number of stomata on leaves affect speed up transpiration rate, to obtain the more accurate calculations of rates. Student t test is also applied during this experiment to see the significance difference between the treatment and the control group.

-6 plants in a soil pot
-6 plastic bags, 6 strings (that can tie the plastic bags)
-A fan
-Tap water
-A notebook (that you can write down all the measurements) and A ruler (1m long)
1. Take all the flowers of the plants out and saturate the plants with water
2. Remove 6 plants from the soil (retaining as much of the root system as possible and keeping soil particle attached to the root)
3. Put the root ball of each plant in a plastic bag, tie the bag around the base (so that only the leaves are exposed) with the string. And label each plants with a letter (A,B,C,D,E, and F)
4. Measure the mass of each plant using the balance, and record the measurements.
5. Place the three plants (that are labelled A,B, and C) on the table where there is no wind.
6. Place the fan on the table and place the plants (that are labelled with letters D,E, and F) 1m away from the fan. (It is important to place all of these three plants close to the location where the other plants that have no wind are because all of these plants need to receive the same variables except the independent variable that is being tested; for example, the same amount of sunlight, heat, and humidity.)
7. Turn of the fan for almost 9 hours a day. *Caution: Do not water the plant during the experiment.
8. Each day, measure the mass of each plant, the percent change in mass of each plant for each day and the surface area of a leaf of each plant.
1.1 Table of mass of each plant and percentage change in mass of the plant for each day:

Day 1
Day 2
Day 3
Day 4
Initial mass