1.how do plants grow when light comes from one side only? Why might plants respond to light this way?
2. What is a circadian rhythm?
3.What controls the change in leaves from night to day?
4.what might the plant leaves change from night to day?
Since this is not my area of expertise, I searched Google under the key words "plant photosynthesis process" to get these possible sources:
https://www.google.com/search?client=safari&rls=en&q=plant+photosynthesis&ie=UTF-8&oe=UTF-8&gws_rd=ssl#rls=en&q=plant+photosynthesis+process
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.
Don't just copy the material. Express the ideas in your own words. Although this will take more time and effort, you will learn more.
1. When light comes from one side only, plants tend to grow towards the light source in a process called phototropism. This response occurs because plants contain a hormone called auxin, which is produced in the tips of the stems and roots. When light is detected by special proteins called photoreceptors, such as phototropins, in the plant cells, these proteins trigger the redistribution of auxin, causing it to accumulate on the shaded side of the plant. As a result, the cells on the shaded side elongate and grow faster than the cells on the illuminated side, causing the plant to bend towards the light source.
Plants respond to light in this way because it is crucial for their survival and growth. Light is necessary for photosynthesis, the process through which plants convert sunlight into energy. By bending towards the light, plants are maximizing their exposure to sunlight, which allows them to produce more energy for essential functions like growth and development.
2. A circadian rhythm is an internal biological clock that regulates various physiological and behavioral processes in organisms, including plants. It refers to a roughly 24-hour cycle of biological activity that is driven by environmental cues, primarily light and darkness. Circadian rhythms help organisms anticipate and adapt to daily changes in their environment, such as the alternation between day and night.
In plants, circadian rhythms control a wide range of processes, including leaf movement, stomatal opening and closing, photosynthesis, flowering, and hormone production. The circadian clock in plants is composed of a network of genes and proteins that interact with each other, forming feedback loops. External cues, like light and temperature, synchronize or "entrain" these internal clocks to align with the external environment.
3. The change in leaves from night to day in plants is primarily controlled by the circadian rhythm. Specifically, the opening and closing of leaves, known as leaf movement or nyctinasty, is regulated by the circadian clock. During the day, under the influence of light, the cells on the upper side of the leaf fill with water and become turgid, causing the leaf to open up and expose a larger surface area for enhanced photosynthesis. Conversely, at night, when light levels decline, the cells lose water and become flaccid, causing the leaf to close or fold up.
This rhythmic leaf movement is an adaptive response that plants have evolved to optimize their energy efficiency and water balance. Closing their leaves at night can help plants reduce water loss through transpiration and protect delicate tissues from potential damage. By contrast, opening up during the day allows plants to maximize their light absorption for photosynthesis.
4. The changes in plant leaves from night to day can vary depending on the species and environmental factors. Some common observable changes include:
a) Leaf movement: As mentioned earlier, some plants exhibit nyctinastic leaf movement, where the leaves open up during the day and close at night.
b) Stomatal activity: Stomata are tiny openings on the leaf surface that regulate gas exchange, including the intake of carbon dioxide and the release of oxygen and water vapor. During the day, stomata open to allow the exchange of gases for photosynthesis, while they tend to close at night to minimize water loss.
c) Color and pigmentation changes: Some plants may exhibit changes in leaf color or pigmentation due to diurnal variations. For instance, certain plants may have leaves that appear lighter or darker depending on the time of day to optimize light absorption.
d) Photosynthesis rates: Photosynthesis, the process by which plants convert light energy into chemical energy, typically occurs during the day due to the presence of light. As a result, the rates of photosynthesis usually increase during daylight hours.
It's important to note that the specific changes in plant leaves from night to day can vary greatly among different plant species and their specific physiological adaptations.