Leaflab Report Essay

Photoperiodism is the effect of the relative lengths of light and dark periods on plant growth. This occurs when photoreceptor proteins e.g phytochromes are produced by plants in response to light intensity or the absence of light. This in effect affects the height of plants. [5]

Plants can absorb a number of different length light waves, although not all of them are equal in power or energy which influences a plants growth. Approximately 80% of light that reaches a leaf is absorbed and depending on its wavelength, may excite chlorophyll pigments (reference text book). Plants absorb both red and purple light waves, however because purple wavelengths are shorter, they contain more energy.

6. Describe several adaptations that enable plants to reduce water loss from their leaves. Include both structural and physiological adaptations.

Introduction: Photosynthesis can be defined as a solar powered process that removes atmospheric carbon dioxide and transforms it into oxygen and carbohydrates (Harris-Haller 2014). Photosynthesis can be considered to be the most important biochemical process on Earth because it helps plants to grow its roots, leaves, and fruits, and plants serve as autotrophs which are crucial to the food chain on earth. Several factors determine the process of photosynthesis. Light is one these factors and is the main subject of this experiment. The intensity of light is a property of light that is important for photosynthesis to occur. Brighter light causes more light to touch the surface of the plant which increases the rate of photosynthesis (Speer 1997). This is why there is a tendency of higher rates of photosynthesis in climates with a lot of sunlight than areas that primarily do not get as much sunlight. Light wavelength is also a property of

Light intensity does affect the rate of photosynthesis. Too much light may cause plants to "burn out" or stop producing oxygen while too little light will not provide enough light for optimal photosynthesis activity and CO2 would stop be taken in and oxygen would stop being produced.

Organisms that use the process of photosynthesis to create sugar to use for energy have a greater rate of photosynthesis when the intensity of the light source is the greatest. If light is far away from the leaves of a plant, for example, then it takes more time for the light to be absorbed and used in photosynthesis. When it takes more time for the light to reach the leaves, the rate of photosynthesis decreases. As the light intensity increases, I would expect the rate of photosynthesis to increase as well. Therefore, I would expect that when the Elodea is closest to the light bulb, the rate of photosynthesis would be the greatest. My hypothesis would be: If light intensity affects the rate of photosynthesis, and the rate of photosynthesis is measured using the amount of

1. (10 points) Write out your pre-lab prediction, including what evidence or previous knowledge you have to support that prediction.

c. Based on your data, how does the amount of available CO2 affect the rate of photosynthesis?

Plant growth is dependent on environment factors and the activities of the meristematic tissues after germination (Dunlop et al, 2010). Some environmental factors that will affect plant growth are soil pH and external stimulus. Most plants can only grow well within a narrow range of pH values; 6-8 (Dunlop et al, 2010). Any soil that is more acidic or basic will result in poor or no plant growth. Phototropism is the growth response of a plant to light due to an unequal distribution of auxin (Dunlop et al, 2010; Tucker, 2006). This causes the plant to grow towards the light source and the cells on the side opposite to the light elongate. Dunlop & Tucker state that this results in the stem curving towards the direction of the light.The meristematic

It was observed that the younger 6-week-old corn leaves produced more oxygen than the 12-week-old corn leaves. This may be from oxidative stress, or anoxia (the absence of oxygen) can result from aging cells, which means it is possible the older 12-week-old corn leaves were exposed to more UV stress, pathogen invasion, herbicide action, and oxygen shortage than younger plants (Blokhina et al. 2003). These are all common environmental factors most corn plants face throughout their life. Oxygen deprivation in plant cells could be a natural process that occurs as the corn ages due to exposure to ecological phenomenon. These influences might cause cell functions to weaken and eventually perish, which are perhaps attributable to an organism’s genetics

The final conclusions of this experiment are that the closer the light source is to a plant, the more light it can absorb, colors farthest from green on the visible light spectrum are most likely to absorb the most light rather than colors closest to green, and only regions containing chlorophyll on a plant can absorb

There are three factors which affect the rate of photosynthesis; Light, Carbon Dioxide and Temperature. When light increases the rate of photosynthesis increases. Photosynthesis increases rate linearly with increasing light intensity (from point A to B, refer to appendix 1) (Passmyexams, 2014). Gradually the rate falls of and at a certain light intensity the rate of photosynthesis stay constant (from point B to C on the graph) (Passmyexams, 2014). When light rise intensity factors such as temperature and carbon dioxide become limiting and has no affect on the rate of photosynthesis (Passmyexams, 2014).

However, the photosynthetic process can be affected by different environmental factors. In the following experiment, we tested the effects that the light intensity, light wavelength and pigment had on photosynthesis. The action spectrum of photosynthesis shows which wavelength of light is the most effective using only one line. The absorption spectrum plots how much light is absorbed at different wavelengths by one or more different pigment types. Organisms have different optimal functional ranges, so it is for our benefit to discover the conditions that this process works best. If the environmental conditions of light intensity, light wavelength and pigment type are changed, then the rate of photosynthesis will increase with average light intensity and under the wavelengths of white light which will correspond to the absorption spectrum of the pigments. The null hypothesis to this would be; if the environmental conditions light intensity, light wavelength and pigment type are changed, then the rate of photosynthesis will decrease with average light intensity and under the white light which will correspond to the absorption spectrum of the pigments.

Plants use a process called photosynthesis in order to turn sunlight into energy, but different species of plants evolved to use photosynthesis in different ways. Most plants use a process called C3 photosynthesis. This type of photosynthesis appears in a wide arrange of temperatures and precipitations. The only places they can’t live in are places that have a mean annual temperature less than twenty-two degrees Celsius and an annual precipitation less than twenty centimeters. There is another process called C4 photosynthesis that, under normal light conditions, does not work very well. Although, if the plant that is using C4 photosynthesis is in a warm, dry habitat, it is more productive than a plant that uses C3 photosynthesis. C4 plants are generally located where the annual temperature exceeds twenty-three degrees Celsius. C4 photosynthesis uses an

All this lights have equally conurbation towards plants growth but without any light then there is no process of photosynthesis which means there no plant growth at all. Photosynthesis is the procedure whereby radian vitality from the sun is changed over to the concoction bond vitality of glucose. In plants it happens in chloroplasts which concentrated cells. Chlorophyll atoms are instrumental in the first step, which is the change of light vitality to the substance bond vitality of ATP. Vitality to change carbon dioxide and hydrogen to glucose is then given by the ATP. Oxygen is discharged as a waste result of procedure. The reaction is shown below: