| Explore | From the radish seed lab, we had the same independent variable or deionized water, so we learned that plants grown with deionized water had a longer total length in centimeters(our DV). Most seeds consist of three parts: embryo, endosperm, and seed coat. The embryo is a tiny plant that has a root, a stem, and one or more leaves. The endosperm is the nutritive tissue of the seed, often a combination of starch, oil, and protein. The seed coat is a protective covering that can help seeds remain viable for long periods of time. Seeds are the byproduct of flowers or flower-like structures, and can be encased in fruits. The seeds that we use to grow food are alive, but they are dormant until they are “activated to grow.” Germination is the process of an organism growing from a seed or spore. The three factors that determine germination for any seeds are; water, oxygen, and the right temperature. These factors essentially activate the seed for it to grow/germinate. The independent variable in our coriander seed experiment is the type of water we use to grow the plants, whether it’s tap water or deionized water. We chose this independent variable because we wanted to see if there would be similar results to our radish lab, where the deionized water allowed the embryos to grow bigger. We chose coriander seeds for this experiment, also known as coriandrum sativum. Some fun facts about coriander are that coriander has been around for centuries and is believed to be one of the oldest herbs used today, it gets its name from a bug, it has great health benefits and healing properties, it bears fruit and flowers, coriander is one of the most widely used herbs. |
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| Research Question | Will deionized water or tap water have an effect on shoot length and leaf count of a coriander plant? Type of water (tap or deionized) will be tested against seedling shoot length and number of leaves over a 8 day period. The purpose of this experiment is to test whether watering with deionized water or tap water would be more effective in having a greater shoot length and number of leaves on a coriander herb. We chose this variable to use because we tested the type of water with radish seeds to find our interesting results of the prior radish lab in class. We can learn based on our research question because we want to find out if more species of plants will have different qualities when watered with tap or deionized water. Our results from prior experiments helped us learn and understand that Radish seeds like deionized water as compared to tap water over 7 days to which we wanted to compare with Coriander! |
| Predictions | If type of water is changed, a coriander plant will see higher number of leaves and a greater shoot length if it is watered with deionized water (experimental) compared to tap water (control) over 8 days. |
| Experimental Design | Constants: - We maintained a consistent every 2 day watering cycle where we used a beaker to measure 20ml of their specific type of water for each pot. - We had 2 coriander seeds per 2 inch pot. - Every pot contained soil around 60g with a +-4g error of margin measured on a standard scale. Experimental group: - Our experimental group is the 10 coriander seeds watered with deionized water. Independent Variable: - Our independent variable for our experiment is the type of water we use to water out seeds before and after germination. We used tap water and deionized water. Dependent Variable: - Our dependent variable is the total shoot length in centimeters and the number of leaves on each plant. We are measuring the shoot length with a ruler on the centimeter side, and counting the leaves on our own. We collected data on October 4th, 6th, and 12th. This data collection was over 8 days. |
| Conclusion | Based on the experimental results, the hypothesis was supported. Coriander plants that were watered with deionized water had a total average of shoot length of 4.81cm and average number of leaves of 2 on day 13, while coriander plants that were provided with tap water had a total average of 6.01cm and an average number of leaves on day 13. This means that if someone were to do this (or a similar) experiment again, we can obtain greater seedling shoot lengths over 7 days when deionized water is used over tap water. One strength was that we managed to keep constants from CG and EG similar to make sure we get best results. We watered pots with 20 ml every few days to make sure they got proper and same amounts of water. We also measured mass of soil and made sure it stayed in an appropriate range to get best results. Another strength was how we collected concise and clear data. We were able to understand which type of water best suited our type of plant and understood our results clearly. A weakness was our execution of our experiment. When planting our coriander seeds, we planted them too deep at a depth of 1-2 cm and suffered the consequences of not being able to collect enough data for the first few days. We can correct this by planting seeds at a lower depth so they have proper measures of germination and being able to retain water, temperature, and oxygen. This could have potentially damped the quality of our data. Another weakness was using a more efficient method of giving our plants light. We noticed that our coriander seedlings did not grow in a upright or healthy manner when it was given sunlight from the classroom. In the future, we will put our experiment closer to proper sunlight that the plant requires to live and survive as a healthy herb. |
| Investigation Theme | WOS |
| Grade Level | High School Students (Grades 9,10,11,12) |
| Teacher Name | Amy Inselberger |
| School Name | Adlai E. Stevenson High School |
| Session | Fall 2021 |