... obtain water, nutrients and oxygen for root respiration, and firm anchorage. Soils are formed by the weathering of rocks, followed by the growth and decay of plants, animals, and soil micro-organisms. ... carbon dioxide and water into sugar (carbohydrates) in the green parts of the plant. The daily amount of photosynthesis is limited by the duration and intensity of sunlight. The amount of carbon ... parts of a plant 7 Most plants consist of roots, stems, leaves and reproductive parts and need soil in which to grow. 8 The root spread through the spaces between the particles in the soil and...