Step-by-step explanation:
The fact that the soil did not change significantly after five years, while the tree gained 74 kg, suggests that the tree's mass did not come from the soil alone. If the tree had gained all its mass from the soil, the soil would have lost an equivalent amount of mass, which did not occur. Therefore, this evidence suggests that the mass of a tree does not come solely from the soil.
While sunlight is necessary for photosynthesis, which allows the tree to produce glucose, the mass of a tree does not come directly from sunlight. Rather, the tree uses the glucose produced during photosynthesis to build its own tissues, such as leaves, branches, and roots. Therefore, while sunlight is necessary for the tree to grow, it is not the source of the tree's mass.
The tree's increase in mass is primarily due to the process of photosynthesis. During photosynthesis, the tree uses energy from sunlight to convert carbon dioxide and water into glucose, which it then uses to build new tissues. Additionally, the tree may have also taken up nutrients, such as nitrogen and phosphorus, from the soil, which it incorporated into its tissues. However, it's important to note that the majority of the tree's mass comes from the carbon that it takes up during photosynthesis, rather than the nutrients in the soil.