What are stomata in plants?A.Tissues that transport water throughout the plant.B.Openings that allow gas exchange to occur.C.Pigments that capture the energy of sunlight.D.Nutrients that surround plant embryos in seeds.

(a) In plants, water is transported through(i) xylem (ii) phloem(iii) stomata (iv) root hair(b) Water absorption through roots can be increased by keeping theplants(i) in the shade(ii) in dim light(iii) under the fan(iv) covered with a polythene bag4. Why is transport of materials necessary in a plant or in an animal?Explain.5. What will happen if there are no platelets in the blood?6. What are stomata? Give two functions of stomata.7. Does transpiration serve any useful function in the plants? Explain.8. What are the components of blood?9. Why is blood needed by all the parts of a body?10. What makes the blood look red?11. Describe the function of the heart.12. Why is it necessary to excrete waste products?13. Draw a diagram of the human excretory system and label the variousparts.Extended Learning — Activities and Projects1. Find out about blood groups and their importance.2. When a person suffers from chest pain, the doctor immediately takesan ECG. Visit a doctor and get information about ECG. You may evenlook up an encyclopaedia or the internet.Did you know?There is no substitute for blood. If people lose blood from surgery or injuryor if their bodies cannot produce enough blood, there is only one way toget it ó through transfusion of blood donated by volunteers. Blood isusually in short supply. Donating blood does not decrease the strength ofthe donors.

Tiny pores are found on the surface of the leaves of plants. These pores are calledstomata. These stomata surrounded by the kidney shaped guard cells provide manyvital functions to the plants.Which of the following functions is not served by the stomata for the plants?(A) Exchange of gases, particularly CO2 and O2, with atmosphere(B) Loss of water in the form of vapours during transpiration(C) Helps to create pressure for the water to rise upward, by its process oftranspiration.

What are the functions of stomata and guard cells, and what would happen to a plant if these cells did not function correctly?Group of answer choicesStomata allow gases to enter and exit the plant. Guard cells regulate the opening and closing of stomata. Photosynthesis and, in turn, transpiration, would not occur which is necessary to maintain a continuous flow of water upwards from the roots to the leaves.Guard cells allow carbon dioxide to enter and exit the plant. Stomata regulate the opening and closing of guard cells. Transpiration and in turn, photosynthesis would not occur which is necessary to maintain a continuous flow of water upwards from the roots to the leaves.Stomata allow oxygen to enter and exit the plant. Guard cells regulate the opening and closing of stomata. If the cells didn’t function, photosynthesis would continue but transpiration would cease, which would interfere with the necessary continuous flow of water upward from roots to leaves.Guard cells allow carbon dioxide to enter and exit the plant. Stomata regulate the opening and closing of guard cells. If the cells didn’t function, photosynthesis and transpiration would cease, which would interfere with the necessary continuous flow of water upward from roots to leaves.

What is transpiration in plants?The movement of water through the phloem cellsThe movement of water through a plant due to evaporation from the leavesThe absorption of water by the root hair cellsThe absorption of water through the leaves2Which substances enter and leave the plant through the stomata?Carbon dioxide enters; water and oxygen leavesWater and oxygen enter; carbon dioxide leavesOxygen enters; carbon dioxide and water leaveCarbon dioxide and water enter; oxygen leaves3Which cells control the opening and closing of the stomata?Guard cellsPhloem cellsPalisade cellsXylem cells4What happens to the rate of transpiration when the temperature is increased?It increasesIt decreasesIt stops altogetherIt stays the same5Why does the rate of transpiration decrease in very humid conditions?Because there will be less water inside the leaf than in the airBecause the rate of photosynthesis increasesBecause the rate of photosynthesis decreasesBecause there will be more water inside the leaf than in the air 6Why are stomata normally found on the underside of leaves?So that they are nearer the ground So that they are protected from rainSo that they are shaded from the sunTo allow water to escape from the leaves by gravity

Stomata are present in the sporophyte generation of the vast majority of land plants, with the exception of liverworts, as well as some mosses and hornworts. In vascular plants the number, size and distribution of stomata varies widely. Dicotyledons usually have more stomata on the lower surface of the leaves than the upper surface. Monocotyledons such as onion, oat and maize may have about the same number of stomata on both leaf surfaces.[2]: 5  In plants with floating leaves, stomata may be found only on the upper epidermis and submerged leaves may lack stomata entirely. Most tree species have stomata only on the lower leaf surface.[3] Leaves with stomata on both the upper and lower leaf surfaces are called amphistomatous leaves; leaves with stomata only on the lower surface are hypostomatous, and leaves with stomata only on the upper surface are epistomatous or hyperstomatous.[3] Size varies across species, with end-to-end lengths ranging from 10 to 80 μm and width ranging from a few to 50 μm.[4]