Zambia
The other three are already well established.
Sunlight is the original source of almost all energy in most ecosystem.
The answer is guard cells.
Guard cells are cells surrounding each stoma. They help regulate the rate of transpiration by opening and closing the stomata. They are specialized cells in the epidermis of leaves, stems and other organs that are used to control gas exchange. They are produced in pairs with a gap between them that forms a stomatal pore (stoma).
In a study of the raw materials used for photosynthesis, the two molecules that would be studied are carbon dioxide and water. This is because they are the reactants of the process. Without these molecules the process of photosynthesis cannot happen.
<em>sieve tube elements are the cells of phloem which allow transportation of photosynthates through phloem...
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how sieve tube elements form sieve tubes:
</u>sieve tube elements are connected end to end and form a long chain which is called sieve tube,,,,
sieve tube elements are connected with the help of a side chain with the help of peptide bond...also one element has tapering end which easily overlaps with other end of next element to form sieve tube,,,,</em>