T<span>he cell requires oxygen, and eukaryotic cells are expensive to run. they require a lot of energy and nutrients, and oxygen is one such component. the oxygen is necessary for aerobic respiration, which allows the cell to do a lot, including evolve, proliferate, adopt new niches, habitats, biochemical habitats, sustain life in extreme conditions, and perhaps eventually co-operate with other cells and create multicellular life. Multicellular life is virtually impossible without aerobic respiration. </span>
DDT is used to repel and kill disease carrying mosquitos <span />
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Answer: A: Its fertile oases enabled farmers to grow enough food for themselves and for sale.
Explanation: The Arabia region is a region located within the Arabian desert. A desert is an area of extreme heat, often dry weather condition with barren lands that cannot support agriculture and food production. An oases on the other hand is a region of luscious, cultivate-able land within a desert.
Food is one of the most important basic needs of man and hardly can anyone survive without food for more than twenty days. Hence, the presence of oases within the otherwise dry environment of the Arabia region is a major protection against death from hunger.
Taking a closer look at other options, none of them guarantees food supply and income to the Arabia region unlike food production in oases. Hence, the fertile oases is really the most important factor that serves as protection in the region's history.
Correct option: A
Answer:The raw materials required for the process of photosynthesis are carbon dioxide, water and solar energy.
The carbon dioxide present in the atmosphere diffuses into the leaf through stomata.
Water is obtained from the plant roots.
Solar energy is obtained from the sun which gets trapped by the chlorophyll pigment present in the leaves.
Explanation: