Grade 6 | Science | Sunlight and Starch | Chapter 5 - Lesson 1

شرح ساينس الصف السادس الابتدائي لغات - الفصل الدراسي الاول شرح ساينس سادسة ابتدائي - ترم اول لينك جروب الواتساب https://whatsapp.com/channel/0029Vaed... لينك تليجرام https://t.me/mrahmedelbashagroup In This Lesson: Photosynthesis Process: Photosynthesis is a process in which green plants use light to make food inside their leaves. For food production, the plant needs to absorb light from the Sun, water from the soil via its roots, and carbon dioxide gas from the air. In return, the plant produces oxygen gas that is released into the air, and sugar that is stored inside the leaves as starch to help the plant grow. Starch Detection Setup: An experiment is used to demonstrate the relationship between sunlight and starch formation in leaves using an iodine solution, which is a liquid chemical that changes from brown to dark blue in the presence of starch. The day before the experiment, one leaf on a plant is covered with aluminum foil to prevent sunlight from reaching it. This light-blocking step ensures that previously stored starch is used up, meaning any starch found later is the direct result of sunlight exposure during the experiment. Experiment Steps: The covered leaf and a sun-exposed leaf are taken from the plant and placed in 80°C hot water for a few minutes to make them soft. Next, the leaves are transferred to a beaker of ethanol in a hot-water bath to remove their green color, which is necessary so the green does not hide the iodine color change later. The leaves are then washed with warm water to remove the ethanol and soften them again before being placed in glass dishes. Results and Conclusion: Drops of dilute iodine solution are added to both leaves. The leaf that was exposed to light turns dark blue, indicating the presence of starch, while the covered leaf remains brown or yellow. This concludes that plants produce sugar through photosynthesis and store it as starch, which only forms when the leaf is exposed to light. بالتوفيق مستر احمد الباشا