Describe the transportation system in plants .

All living organism need some method of moving substances from one part of the body to other parts of the body. For example, in living organisms food and oxygen are moved in the body to all the cells and waste materials such as carbon dioxide is taken away from them. The system of moving substances in different parts of body is called transport system. In plants, food and water are transported by bundles of tubes present in stem called phloem and xylem. In animals, food, water and respiratory gases (oxygen and carbon dioxide) and other substances are transported by blood.

In plants, transport system is not complicated as in animals. The transport system in plants consists of bundles of tubes in the stem, branches and roots. These tubes are called xylem and phloem. The main function of xylem is to transport water and dissolved minerals from the roots to rest of the plant body. While, the phloem transports the food manufactured in the leaves to all parts of the plant.

a. the production of carbon dioxide through the process of photosynthesis

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.