1) how do photosynthesis occur
2) what do you mean by double circulation? mention its advantages.
3) Explain any three methods used by plants to get rid of excretory product?
4) What are stomata and lenticels?
Answers
Answer:
1....How does photosynthesis happen?
Photosynthesis happens when water is absorbed by the roots of green plants and is carried to the leaves by the xylem, and carbon dioxide is obtained from air that enters the leaves through the stomata and diffuses to the cells containing chlorophyll.
Where does photosynthesis take place and why?
Photosynthesis takes place inside plant cells in small things called chloroplasts. Chloroplasts (mostly found in the mesophyll layer) contain a green substance called chlorophyll. Below are the other parts of the cell that work with the chloroplast to make photosynthesis happen.
2....What is meant by double circulation?
Definition of double circulation. : a circulatory system in which the blood makes two distinct circuits — compare pulmonary circulation, systemic circulation.
Advantage of double circulation:Higher blood pressure is maintained. There is a greater flow of blood to the tissues. Double circulation gives the ability to create more pressure to pump blood round the whole body system. There is separation of oxygenated and deoxygenated blood.
3....To get rid of excretory products, plants use the following ways:
(1) Many waste products are stored in vacuoles of the cells. Plant cells have comparatively large vacuoles.
(2) Some waste products are stored in the leaves. They are removes as the leaves fall off.
(3) Some waste products such as resins and gums are stored, especially in non-functional old xylem.
(4) Some waste products such as tannins, resins, gums are stored in bark, thereby removed as peeled off.
(5) Plants excrete some waste products through roots into the soil around them.
(6) Plants also get rid of excess water through transpiration.
4....Stomata is similar to a pore found in the epidermis of leaves,stem and other organs that are used to control gas exchange. They allow gas exchange of carbon dioxide, water vapor and oxygen to move rapidly in and out of the leaves. ... A lenticel is a spongy area present in the woody surfaces of stems.
Stomata are present on leaves to help in photosynthesis and respiration. ... Lenticels are small pores that are found on the stems. ... ✔Stomata regulates the process of transpiration that is water vapour is released in the atmosphere and gaseous exchange.
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