Sample Test Report Text

1. Destination

To study and observe the effect of light on the growth of green beans.

2. Theoritical review

Germination is the process of growth of the embryo and seed components that have the ability to grow normally into new plants. The seed component is the germination part contained in the seed, such as the radicle and plumule. The germination stage is the development of seeds related to chemical aspects.

The process includes several stages, including imbibition, hormone secretion to the growing point area or other areas, and assimilation (photosynthesis). The process of absorption of liquid in the seeds (imbibition) occurs through the microfil. Water that enters the cotyledons swells. The swelling eventually causes the testa to rupture. Early development is preceded by the activation of hydrolase enzymes (protase, lipase, and carbohydrase) and hormones in the cotyledons or endosperm by the presence of water. The protease enzyme immediately goes to work converting protein molecules into amino acids. Amino acids are used to make new protein molecules for cell membranes and cytoplasm.

Starch deposits are broken down into maltose and then into glucose. Some of the glucose will be converted into cellulose, which is the material for making the cell walls of new cells. material Dissolved food in the form of maltose and amino acids will diffuse into the embryo. All of these processes require energy. Seeds get energy through the breakdown of glucose during the process of respiration. The breakdown of glucose from starch deposits causes the seeds to lose weight. After a few days, the plumules grow above the soil surface. The first leaf opens and starts doing photosynthesis. The definition of germination is not only used specifically for seeds but also for other plant parts.

Factors affecting growth and development in plants

Visually and morphologically, a germinating seed is generally characterized by visible roots or leaves protruding from the seed. Plant growth is influenced by several factors, including the following.

• Water. Water serves to keep plants fresh and not wilted as well as media chemical reactions in cells, support photosynthesis and maintain moisture. If the plant lacks water, it will cause the plant to become dry or lack nutrients. Excess water also makes plants stunted and in the worst case, the plants will die.
• Temperature. A good temperature for plants is 30 degrees Celsius. The higher it is temperature in the environment of a plant, the faster the transpiration rate and the lower the water content in plants, so the growth process will be slower. Treatment of plants at low temperatures stimulated the growth of longer internodes than treatment of plants at high temperatures. The function of the temperature itself is to activity enzymes and water content in the plant body.
• Oxygen. Oxygen functions as respiration of root cells which will be related to the absorption of nutrients. If the oxygen obtained grows only slightly then the growth of plants will be hampered because it will be difficult to absorb nutrients in the soil.
• Light. Plants that are placed in a shady place will grow with characteristics of light green leaves and roots that are not too thick. In contrast to plants that are planted in places that get a lot of light, the plants will have characteristics light green leaves, the stomata will be numerous but small in size, the roots are denser and the growth is more fast. Several processes in plant development that are controlled by light include germination, stem elongation, leaf expansion, chlorophyll synthesis, stem movement, leaf movement, flower opening and shoot dominance.

Effect of light on plants

Light affects the process of photoperiodism and phototropism in plants. Photoperiodism is the response of plants to periods of exposure to sunlight and is usually controlled by phytochromes. The amount of light needed is not always the same in every plant. Generally, light inhibits growth because light can break down growth hormone, namely auxin. We can see this in plants that are in a dark place which grows faster than plants that are in a light place. Rapid growth in the dark is called etiolation.

Meanwhile, what is meant by phototropism is the response of plants in the form of movement of part of their body to light. For example, the movement of sprouts in the direction of the light. Phototropism movement is influenced by levels of the hormone auxin at the tip of the stem. Auxin hormone plays a role in stem elongation. Auxin will be destroyed if exposed to sunlight and its growth will be stunted.

3. Tools and materials

The tools and materials needed for this practicum are as follows.

• 3 cup cups or used jam
• Carbon paper/aluminum foil
• Cotton
• Green bean seeds
• Enough water

4. Procedure/How it Works

The procedure or how to work this practicum is as follows.

• Do a good selection of green beans by soaking for 1-2 hours. The sinking seeds are good seeds that are commonly used for experiments.
• Prepare 3 clean bottles then coat the bottom of the bottle with cotton that has been moistened with enough water.
• Add 10 selected green beans each and cover the top with aluminum foil.
• Perform treatment on each bottle as follows.
  • Bottle 1, covered with aluminum foil so that no light enters the bottle.
  • Bottle 2, covered with aluminum foil but given a small hole on the edge of the bottle.
  • Bottle 3 is left open.
• Leave the three bottles and observe them after 1 week.
• Make observations in tabular form.

5. Observation result

The results of the observations of the three bottles are as follows. (Note: All in cm)

Treatment	Plant height
1	2	3	4	5	6	7	8	9	10
1 bottle	25,5	18,5	22	20	26,5	19	24	28	6,5	2,5
2 bottle	33	16,5	28,5	20	27,5	22	11,5	24	16,5	20,5
3 bottle	20	22	15,5	1	1,5	–	–	–	–	–

• Bottle 1: all grew successfully, 2 seeds had growth problems (9th and 10th seeds). From these results, the average plant height was 19.25 cm.
• Bottle 2: all managed to grow perfectly. From these observations, the average plant height was 22 cm.
• Bottle 3: 5 mung bean seeds successfully grew and 5 mung bean seeds failed (4 seeds did not grow and 1 was moldy) and 2 out of 5 seeds that grew had growth problems. From these observations, the average plant height was 22 cm.

6. Discussion

Growth on the side of the plant that is illuminated by the sun will occur slowly because the hormone auxin is inhibited by the sun. But the side of the plant that is not exposed to sunlight grows very quickly. This is influenced by several factors, namely internal and external factors from outside. Germination is much influenced by light and hormone factors. So this will cause the tip of the plant to tend to follow the direction of sunlight or what is called phototropism.

In the absence of light, auxin stimulates the elongation of cells so that the sprouts in the dark will grow longer but with a pale yellowish condition, thin, and the leaves do not develop. While the sprouts that grow in the light, the auxin is damaged so that the growth of sprouts is inhibited. The elongated growth rate on these sprouts is immediately reduced so that the stems are shorter, but grow stronger, the leaves are fully developed, and are green.

Bottle 1 that is closed produces a plant with longer roots, less vigorous stems and grows faster. This is because the humidity in the bottle is quite high and cannot photosynthesize. Opened 3 bottles produce plants with shorter roots, slower growing, stronger stems but some die. This may be due to the many influences that can damage the plant from the outside that enter the bottle. The half-opened bottle 2 produces plants with intermediate characteristics between bottles 1 and 3. The results of the experiment were errors that occurred due to poor covering material or seeds.

7. Conclusion

Based on the observations that have been made, it is concluded that germination is much influenced by light, hormones, and a few other factors that influence it.

Observing the light factor, it is proven that green beans placed in less dark areas will resulted in faster growth of green beans compared to green beans placed in place bright. This is due to the hormone auxin in a less dark area not exposed to sunlight so that it stimulates the elongation of cells at the primary growth point. However, a good plant condition is actually deepened by green beans which are heavily influenced by sunlight. The conditions in question include growing stronger, fully developed leaves, and green. It's just that the stems are shorter when compared to green beans placed in a dark place. Meanwhile, unfavorable plant conditions experienced by green beans that grow without the influence of sunlight, namely the stems are taller faster, the leaves do not contain chlorophyll, and are yellow.

It can be concluded that light slows or inhibits the growth of green beans and this happens because light can decompose the hormone auxin.

Bibliography

1. http://shawolmyword.blogspot.com/2012/11/laporan-praktikum-biologi.html
2. http://makalahpengaruhcahayaterhadaptanaman.blogspot.com/
3. http://kecambahkacanghijau.blogspot.com/
4. http://imaairana.wordpress.com/pengaruh-intensitas-cahaya-terhadap-pertumbuhan-kacang-hijau/