Seed of Germination Experiment 1 Title: The effect of the presence of water on seed germination Research question: What is the effect of presence of water on seed germination? Hypothesis: Water is needed in seed germination. Variables: (a) Independent : The presence of water (b) Dependent : Seed germination (c) Constant : The number of peas, the duration of experiment, temperature Apparatus and Materials: 3 containers labelled as A, B, and C, dry cotton wool, soaked seeds, dry seeds, water and lids
Data Collection:
Container (its The average average length of plumule plumule and radicle radicle of condition) each green bean, l (cm) Observation A No germination (soaked pea s 0.00, 0.00 occurred. and and dry dry cott cotton on wool) Seed germi germinati nation on B occurred. Th e (soaked pea s 1.76, 11.80 leng length th of radi radicl clee and and wet wet cott cotton on was was long longer er than than wool) wool) plumule. Seed germi germinati nation on C occurred. Th e (soaked pea s 1.76, 11.34 leng length th of radi radicl clee cover vered with was was long longer er than than water) plumule.
Data Processing and Discussing:
1. In container A, there was no water and no absorption of water occurred. So that, no germination was occurred. Without water, gibberellin(growth hormone) will not produced and no amylase production occurs to convert starch to maltose in the food stores of the seed. 2. In container B, there was water and water diffuses through the seed coats into the embryo and causing a swelling of the seed that cause the seed coat to rupture. After the absorption of water, gibberellin is produced to stimulate the amylase production. These amylase catalyses the digestion of starch into maltose in the food stores of the seed. 3. In container C, there is excess of water and the soaked bean is covered with water. The germination process occurs normally. But after a period of time, the germination is terminated because the plant is not a water type plant. Evaluation:
1. In container C, the result is different from the expected result. This is because the amount of excess water covering the seeds is not enough as water might evaporate and expose the seeds to the atmosphere. Although the seeds are completely covered with water, the size of the container is too small to support cotton wool and seeds. Thus, larger container must be used so that the seeds will really drown into the water with at least 3 cm from the water surface. 2. In order to avoid evaporated water molecule from going outside, the lid is used to close the container. So, when the water evaporates, it will condense back to its liquid form under the lid surface. Then, the cotton wool will always become wet.
Experiment 2 Title: The effect of the presence of oxygen on seen germination Research Question: What is the effect of the presence of oxygen on seed germination? Hypothesis: Oxygen is needed for seed germination. Variables: (a) Independent : The presence of oxygen (b) Dependent : Seed germination (c) Constant : Temperature, water, the period of experiment Apparatus and Materials: 2 conical flasks, moist cotton wool, pyrogallic acid, sodium hydroxide, eye shield, cress seeds, bungs, bent pin, thread, and water Data Collection:
Conical flask Observation A No seed germination occurred for all seeds. (with pyrogallic acid and sodium hydroxide solution) Seed germination occurred for all seeds B with average length of plumule and radicle (with water) is 5 cm. Data Processing and Discussing :
1. In conical flask A, pyrogallic acid and sodium hydroxide are used to absorb oxygen presents in the conical flask. Without oxygen, no aerobic cell respiration occurs and no energy produced. So, no seed germination occurs. 2. In the conical flask B, oxygen is available and will be absorbed by the cress seeds and used in aerobic cell respiration to produce energy that is needed for growth. Thus, germination occurs. Evaluation:
1. In conical flask A, the moist cotton wool must not touch the solution because the solution will be absorbed by the cotton wool and inhibit the seed germination. 2. The solution of pyrogallic and sodium hydroxide can evaporate and later poison the cress seed. So, the solid substance that can absorb oxygen must be used. 3. The conical flask must be an air tight flask so that the oxygen from the outside atmosphere will no come into the flask and affect the result.
Experiment 3 Title: The effect of different temperature on seed germination Research Question: What is the effect of different temperature on seed germination? Hypothesis: Different temperature will have different effect on seed germination. . Variables: (d) Independent : Temperature (e) Dependent : Seed germination (f) Constant : Water, the presence of oxygen, the duration of experiment, the absence of light Apparatus and Materials: Soaked maize grains, moist filter papers, plastic bags, refrigerator, black coloured paper, paper clips, and ruler Data Collection:
Length of plumule and radicle, l (cm) 1 0.0
2 0.0
3 0.0
Average length of plumule and radicle, l (cm) 0.0
12.2
13.5
13.3
13.0
11.5
11.4
10.9
11.3
0
Temperature, T ( C)
0 (in the refrigerator) 20 (in the incubator) 30 (in the room) .
Data Processing and Discussing :
1. Seed requires suitable temperature for seed germination because it involves enzymes activity. 2. At the extremely low temperature like 00C, there will be no enzyme activity occurs. Maize seeds will remain dormant and not germinate. 3. With temperature 200C, the seed germination for maize occurs very well because the enzyme in maize seeds function very well at optimum temperature. 4. As the temperature increases to 300C, the germination still occurs. Enzyme activity occurs but at the slower rate compared to the condition with 200C. Evaluation:
1. Black coloured paper must be used to prevent each polythene bag from obtaining the exposure of light because some seeds also require adequate exposure to light before germinating. So, light need to be controlled.
Conclusion:
In experiment 1, seeds need water for germination and in the experiment 2, seeds need oxygen for germination. While, in the experiment 3, seed will germinate at suitable temperature like 200C for maize seed. Therefore, the hypotheses are accepted.
