Question

how does a plant take in the gases it needs?
plants take in carbon dioxide and give off oxygen. these gases move into and out of the leaf through openings called stomata (singular, stoma). stomata allow gases to move through the plants cuticle, the waxy layer that prevents water loss. each stoma is surrounded by two guard cells. the guard cells act like double doors by opening and closing a stoma.
water vapor also moves out of the leaf through stomata. the loss of water from leaves is called transpiration. stomata open to allow carbon dioxide to enter a leaf. they close to prevent too much water loss.

why is photosynthesis important?
plants, along with many bacteria and protists that also use photosynthesis, form the bases of most food chains on earth. during photosynthesis, plants store light energy as chemical energy. animals get this energy when they eat plants. other animals get energy from plants indirectly. they eat the animals that eat plants. most organisms could not survive without photosynthetic organisms.
photosynthesis is also important because it produces oxygen. recall that cellular respiration requires oxygen to break down food. most organisms, including plants and animals, depend on cellular respiration to get energy from their food. without the oxygen produced during photosynthesis, most organisms could not survive.
critical thinking

1. predict what do you think would happen if a plant had no stomata?

take a look

1. identify circle the guard cells in this picture. what is their function?

say it
describe think of all the ways in which photosynthesis is important to you. describe to the class three ways you depend on photosynthesis.

reading check

1. complete during photosynthesis, plants store light energy as

Explanation:

• Question 5: Without stomata, plants can't take in carbon dioxide (needed for photosynthesis) and can't release oxygen. Also, water vapor loss (transpiration) which helps in nutrient uptake and cooling won't occur. So plants would struggle to make food (photosynthesize), can't respire properly (as gas exchange is affected), and may over - heat and dry out.
• Question 6: Guard cells are around the stoma. Their function is to open and close the stoma (like double doors) to regulate gas exchange (let in carbon dioxide, release oxygen) and water vapor loss (transpiration).
• Question 7: During photosynthesis, plants store light energy as chemical energy (in the form of glucose, for example).

Answer:

• Question 5: The plant would not be able to take in carbon dioxide for photosynthesis, not release oxygen, and have issues with water regulation (transpiration). It would likely die as it can't make food, respire properly, and manage water balance.
• Question 6: Guard cells are the cells surrounding the stoma. Their function is to open and close the stoma to control gas exchange (CO₂ in, O₂ out) and water vapor release.
• Question 7: Chemical energy.