Q.1 There are two main reasons why roots branch out in the soil:
To increase the surface area for absorption: The root system of a plant is responsible for absorbing water and nutrients from the soil. By branching out, the root system can increase its surface area and come into contact with more soil particles, increasing the plant's ability to absorb water and nutrients.
To provide stability and support: A plant's roots also help to anchor it in the soil and provide support. By branching out, the roots can spread and anchor the plant more effectively, especially in loose or unstable soil.
Q.2 Many leaves are broad and thin because this shape maximizes their ability to carry out photosynthesis, the process by which plants convert sunlight into energy. The broad shape of the leaf provides a large surface area for sunlight to be absorbed, while the thinness of the leaf ensures that light can penetrate through to the lower layers of cells, where photosynthesis occurs. The thinness of the leaf also facilitates the exchange of gases, allowing for the uptake of carbon dioxide from the air and the release of oxygen, which is a byproduct of photosynthesis. Additionally, the broad shape of leaves allows for the efficient dissipation of heat, which can build up during photosynthesis and potentially damage the plant's cells. Overall, the broad and thin shape of leaves is well-suited to the plant's need for efficient photosynthesis and gas exchange.