Question

What is the main water source for land plants?

a. rain

b. soil

c. biomolecules

d. essential nutrients

Short answer

b. soil

Step-by-step solution

Step-1 Introduction

As life first originated in aquatic environments, water is one of the essential requirements for plants when they start to evolve on land. Gradually plants adapted various modifications to fulfill the requirements for water. Both nutrients and water are required for the proper growth and development of plants.

Step-2 Explanation

The root system has evolved in land plants to absorb water from the soil. Rain provides water but plants cannot use the rainwater directly. The root helps in the conduction of water from the bottom to the top of the plant. Biomolecules and essential elements do not provide water to the plants, but the soil is the only source that provides the stored water and through roots, plants get the water from the soil.

Rain cannot be the main water source because the plant is unable to use rainwater directly. The water from the soil is absorbed by roots.

Biomolecules are helpful for the growth and development of plants. They are not the source of water. Biomolecules are produced by energy-yielding processes.

Similar to the biomolecules essential nutrients are also required for plant growth and development.

Step-3 Final answer

Therefore, the correct answer is option ‘b’.

Soil is the main water source for land plants