Plant Science Lab Report

Controlled Variable:

• Same type of plant        
• Same location
• Same amount of water in plants
• Same casing for the plant
• Same amount of soil

Independent Variable: - Concentration of NaCl (0%, 5%, 15%, 10%)

Dependent Variable: - Growth of plant

Materials:

1. NaCl [salt]
2. 4 plants of the same kind
3. 50 ml beaker
4. Measuring cylinder
5. Electric balance
6. Spoon
7. A glass rod for stirring
8. 20 cm ruler

Method:

1. Gather all the materials needed
2. Place the four plants next to each other in a position where they can get the same amount of sunlight
3. Fill the four beakers with 15ml of water each. Use the measuring cylinder to pour 15ml of water into each beaker
4. Pour the first beaker on one of the plants and label that plant “A”
5. Place the second beaker on the electric balance
6. Set the balance to zero
7. Add NaCl [salt] using the spoon until you get the balance to 5g, which means 5% of NaCl
8. Stir the NaCl in the beaker until it dissolves into the water
9. Pour the beaker onto one of the plants and label that plant as “B”
10. Repeat steps 5 to 9. But in the third beaker place 15g of salt and label the plant with the 15g of salt as “C”. In the fourth beaker place 20g of salt and label the plant with the 20g of salt as “D”
11. Using the ruler, read the height of each plant daily for seven days

Labelled Diagram:

Results:

Data Processing:

Conclusion: From the table of results we can clearly see that plant “a” was not affected due to the non existence of salt [NaCl] in it. However, the other plants have all died due to the presence of salt in them. This is because salt in plants dehydrates the cells in plants causing the plants to die. The salt has also affected the process of photosynthesis by stopping it. The table and the experiment clearly prove that my hypothesis was correct and that salt or NaCl does kill plants instead of feeding them and as it kills them it decreases their size. If we refer to the numbers in the table and the graph we can clearly see that the plants with salt in them have decreased in size, the 5% NaCl (b) has decreased by 0.3cm, the 15% NaCl (c) has decreased by 0,4cm, and the 20% NaCl (d) has decreased the most by 0.5cm. So we can also conclude that the more you add NaCl to a plant the plant decreases more. From the table we can also see the plant d (20% NaCl) has the highest rate of decrease. So we can also conclude from our processed data that the more NaCl you add the higher the rate and the higher the decrease. So in conclusion my hypothesis was correct and we were also able to discover other conclusion about the effects of NaCl on plant growth.

Evaluation: