What is the function of the stomata?
The stomata are openings (pores) on the surface of the leaf that allows water, carbon dioxide, and oxygen to enter and exit the plant leaf. Plants take in carbon dioxide through these pores. Oxygen and water in the gas phase exit the leaf through the stomata.
What is the function of guard cells?
Guard cells control the size of the opening of the stomata. They swell and contract by absorbing water. Water moves in and out of the guard cells by osmosis. As the guard cells absorb water they swell and the stomata opens. When the guard cells lose water the stomata close. Guard cells are important for transpiration because they allow water to move in and out of the plant for transpiration.
How are materials moved inside a plant?
The xylem transports water and dissolved substances up from the roots. The phloem moves food from where it is made to other parts of the plant where it is used or stored until needed.
What is transpiration?
During transpiration water is lost from the leaf. The process of transpiration helps to cool the plant and transport the water from the root system up to the leaves. About 15% of the water absorbed is used in the production of food for the plant. Transpiration contributes water vapor to the air, thus increasing the level of humidity. About 85% of the water absorbed by plants is transpired back into the atmosphere.
What is gas exchange?
Gas exchange is one way that plants obtain raw materials to produce food and release waste products. Gas exchange is the movement of carbon dioxide, oxygen, nitrogen, and water vapor through the stomata. The leaf absorbs carbon dioxide and uses this for food. Nitrogen is used in the roots. The plant gives off oxygen and water vapor.
What is the function of the cuticle?
The cuticle is the leaf's upper layer. The cuticle is a waxy protective layer covering the leaf. If the cuticle is thick and waxy, the rate of transpiration is slow. If the cuticle is thin and non-waxy, the rate of transpiration is faster.
How are photosynthesis and transpiration related?
The length of daylight and air temperature determine the amount of photosynthesis that occurs in a plant. Photosynthesis is increased during longer days and higher temperatures (summer). The greater the amount of photosynthesis, the greater the rate of transpiration. In the winter, photosynthesis is decreased as well as transpiration.
What is the function of the plant’s roots?
Water and dissolved substances enter the plant through its roots. Roots also anchor the plant and sometimes store food. A typical tree absorbs more than 200 gallons of water a day!
Here are some definitions to help you in your Grade 3-5 Lesson 1 investigation.
Temperature - how hot or cold something is
Rate - how fast or slow something happens
Transpiration - a form of water loss in plants
Evaporation - moving from the liquid to the gas phase
Pore - an opening in a structure
Environment - the area where a plant or animal lives
Observations - using senses to notice what is happening
The leaves of plants have openings called stomata that allow gases to move in and out of the plants. When these pores are open the plant loses water. This loss of water through leaves is called transpiration. Your challenge is to find out what factors affect the transpiration rate of a plant. You'll use probes to investigate these various factors. If this sounds a little too complicated, don't transpire, I mean perspire. Everything should become as clear as water once you complete your challenge.
