a student estimating the cell size of onion cells observed millimeter marks on the microscope field of view. She counted 20 cells along the diameter of the field of view. Calculate the size of one cell in micrometers
Assuming the diameter of the field of view is 1 millimeter, and there are 20 cells along the diameter, we can estimate the size of one cell as follows:
1 millimeter = 1000 micrometers (since there are 1000 micrometers in one millimeter)
So the width of the field of view in micrometers is:
1000 micrometers / 20 cells = 50 micrometers per cell
Therefore, the estimated size of one onion cell is 50 micrometers.
state two importance of the process of transpiration
1. Water transport: Transpiration is a process that helps in the transport of water and minerals from the roots to the various parts of the plant. It creates a negative pressure gradient that helps in the upward movement of water up the xylem vessels, against gravity, from the roots to other parts of the plant. This process helps in maintaining turgor pressure, and ultimately, the rigidity of plant tissues.
2. Cooling effect: Transpiration provides a cooling effect that helps in maintaining the temperature of the plant and the environment. The water vapor that is released through stomata carries away excess heat, which cools the plant tissues and prevents damage due to high temperatures. This process also helps in maintaining the humidity levels in the surrounding environment, which can be beneficial for other organisms living in the ecosystem.
explain how sunken stomata reduce the rate of transpiration
Sunken stomata are stomata that are located in small depressions on the surface of the leaf, rather than being exposed to the external environment. Sunken stomata reduce the rate of transpiration in the following ways:
1. Protection from wind: Since the stomata are located in small depressions, they are shielded from the wind. This reduces the movement of air around the stomata, and therefore, reduces the rate of water loss through transpiration.
2. Reduction of exposed surface area: The recessed stomata are located in little pits, which reduces the area exposed to the atmosphere. This reduces the rate of transpiration because there is less surface area for the water to evaporate from.
3. Retention of Moisture: The depressions around the stomata tend to be covered with epidermal cells, which secrete a waxy cuticle layer. This layer helps to retain moisture around the stomata and reduce water loss.
These combined factors of reduced wind, reduced exposed surface and retained moisture, all work together effectively in reducing the rate of transpiration.
To calculate the size of one cell in micrometers (µm), you need to know the diameter of the field of view in millimeters (mm) and the number of cells along that diameter.
1. First, convert the diameter of the field of view from millimeters to micrometers. Since there are 1,000 micrometers in one millimeter, you can convert the diameter by multiplying it by 1,000.
2. Next, divide the converted diameter by the number of cells counted along that diameter. This will give you the size of one cell in micrometers.
Let's calculate it step by step:
Given information:
- Number of cells along the field of view diameter: 20 cells
- Diameter of the field of view in millimeters: unknown
1. Calculate the diameter of the field of view in micrometers:
- Convert the diameter from mm to µm by multiplying it by 1,000.
2. Divide the converted diameter by the number of cells:
- Divide the converted diameter by 20 to obtain the size of one cell in µm.
For example, let's assume the diameter of the field of view is 5 mm:
1. Convert the diameter from mm to µm:
- Diameter in µm = 5 mm × 1,000 = 5,000 µm
2. Divide the converted diameter by the number of cells:
- Size of one cell in µm = 5,000 µm / 20 cells = 250 µm
Therefore, in this example, the estimated size of one cell in micrometers is 250 µm.