Investigating Rate of Transpiration

The room temperature had little or no effect on the water potential. The mist increased the water potential of the air causing less transpiration to occur from the leaves.

The tropical rainforest plays a significant role in regulating the water cycle on earth, through transpiration and evaporation process. Transpiration is the water vapour loss from plants through stomata, and evaporation is the water loss from all other part of plants but leaves and other living things in the forest. Evapotranspiration are the accumulation of transpiration and evaporation in the forest. During transpiration, trees suck water from soil through the root system and transport the water to leaves through xylem, and then release the water to the air through stomata. Transpiration happens simultaneously with photosynthesis.

Transpiration is said to be the loss of water vapor through the stomata of the leaves in a plant. Transpiration essentially serves to move water and other nutrients throughout a plant, to cool down plants and humans and to maintain turgor pressure in the cells of plants (sdhydroponics). The transpiration rate in a plant is affected by the wind, light and humidity. temperature and water. The wind serves to determine how dry the air is when transpiration occurs. Light can at times speed up the rate of transpiration in plants. Transpiration tends to occur faster in the light rather than when in the dark. Humidity serves to determine the rate of the diffusion of water in the plant. As

Diffusion, osmosis and active transport of substances in and out of the membrane is very important for all types of cells. One example is the root hair cell. These cells are the exchange surface in plants which are responsible for the absorption of water and mineral ions so without osmosis and active transport this would not be possible. The water is taken up by osmosis through the partially permeable membrane. The root hair cells are surrounded by a soil solution which contains small quantities of mineral ions but mainly water, so has a high water potential (slightly less than zero). The root hair cells themselves contain a high quantity of amino acids, mineral ions and sugars inside them (low water potential). Therefore water will move by osmosis from the soil solution and into the root hair cells, going down the water potential gradient.

Plants need specific conditions to grow. In this experiment plant will be put in hypertonic solutions. Three out of the six plant will be watered with a salt and water solutions. Watering the plants in the solution will place them in a hypertonic solutions, making the water leave the cells to diffuse (in this case) the salt. “Photosynthesis is the process in which plants use water, carbon dioxide, and light energy to make glucose and oxygen.”(PHOTOSYNTHESIS). If water is needed for

Evaporation (transpiration) Heat from the sun warms water from rivers, lakes, and the ocean to turn into vapor or steam; leaving the reservoir and moving upwards into the atmosphere. (Plants transpire, or lose water from their leaves).

Our hypothesis was rejected because the plant in the cold temperature of 0°Celsius, had the greatest amount of oxygen produced from the starting point of 24% with a 1.60% increase. The room temperature of 23.33°Celsius was a close second with a 0.70% increase from the initial amount of 24%. The hot temperature of 40°Celsius was the lowest with a decrease of -2% from the starting amount of 24%. We noticed that the amount of oxygen produced increased as the temperature decreased. Though we believe if the temperature was lower than 0°Celsius then our results would be different, and the plant wouldn’t produce as much oxygen. The rate of photosynthesis depends on: light intensity, temperature, and the availability of carbon dioxide, and water. When

Peak expiratory flowing rate or PEFR is the highest rate of air flowing out when a person performs a forced breath out. PEFR is measured in very short period time; usually, the rate of air flow is estimated simultaneously when he or she breathes out. The most significant factor influencing PEFR is how much bronchial airways are obstructed. PEFR also depends on other factors such as height, age and gender. Thus, PEFR is not an absolute indicator to determine airway resistance; hence, it is imperative to assess PEFR values with respect to all factors. (Generally, it implies that) the results obtained from tests need to be considered within an appropriate range of height and age in which people belongs to.

A submerged plants will have a hyponastic response caused by a buildup of the compound ethylene (Visser et al., 1996). Ethylene is found in higher concentrations in submerged plants when compared to non-submerged plants and has been shown to enhance the growth of the petiole during water logging (Monaco & Cumbo, 1972). In flooded conditions petiole elongation contributes to the increases survival of the plant by enabling leaves to reach the water surface (Visser et al., 1996). Highly coordinated enhancement in the upward growth of shoot stems and petioles enables continuation of gas exchange and aerobic metabolic activity (Voesenek, 2003). In waterlogged condition petioles are not submerged and as such it is expected that ethylene will instead contribute to increased root elongation by enabling adventitious roots to form (Monaco & Cumbo,

Thus, in this experiment, we are required to determine the rate of photosynthesis of leaf disc. But first, we must know that,

Each day we got a new set of leaves from the same tree, one leaf was green and the other one was brown and stiff. We set up our experiment at 9:14am and gathered the amount of water used. We placed the leaves in two separate container lids and poured 40 ml of water into each lid by using a graduated cylinder. We first measured the temperature of the water and then the temperature of the leaves. We left the leaves outside for 4 hours in order for the leaves to be able to consume enough sunlight. Once the four hours were up we went to check up on the leaves at 1:14pm. We measured the temperature of the leaves by using the infrared temperature gun and recorded our data. We then repeated these steps for the following trials to have constant data.

How does water get into a plant? First, the plant transpires, which is the loss of water due to evaporation through the stomata. The cuticles on the plant help prevent water from being lost. Transpiration is regulated by the stomata. The stomata is surrounded by guard cells that open when there is a lot of sunlight, carbon dioxide, and leaf water status in the atmosphere. The stomata opens to allow air with carbon dioxide and oxygen into the plant. This helps the plant go through the processes of photosynthesis and respiration. When the stomata is working, the water in the plant slowly dissipates. The plant goes through homeostasis, so it does not lose too much water while it is photosynthesizing. The evaporation from the mesophyll cells creates

Photosynthesis is a process used by plants and other living organisms that use light energy from the sun into chemical energy that can later be used as energy for other organisms. Numerous factors that influence the rate of which photosynthesis occurs, which includes temperature, amount of light and carbon dioxide. The aim of the experiment was to investigate the effect of increasing concentration of carbon dioxide on the rate of photosynthesis. For example, to test the hypothesis, the effect of changing concentrations of carbon dioxide on the rate of photosynthesis in leaf discs was measured. This was done by removing air bubbles from the leaf discs, which caused the disc to sink to the bottom of the syringe and by placing them in different concentrations of sodium bicarbonate. The results on the graph started to decrease as the concentration level of the sodium bicarbonate was increased. A summary of errors occurred from some leaf discs floating before the experiment began (at time zero). However, results of the experiment supported the hypotheses, even though there were several errors

Respiration functions in the exchange of oxygen gas and carbon dioxide. External respiration occurs when oxygen is drawn into the lungs when breathing in while carbon dioxide is expelled from the lungs when breathing out. On the other hand, internal respiration takes place when the oxygen gas is consumed by the cells for cellular function. Respiratory rate is the number of respirations per minute. Eupnea, which refers to the normal respiratory rate, is influenced by several factors such as age, activity, illness, size, and temperature.

When a plant cell is bathed in a solution of the same concentration (isotonic) as its intracellular environment, its mass and volume remain the same. This is because water enters and leaves the cells at the same rate. There is no net loss or gain of water by osmosis.