Question

Roots play insignificant role in absorption of water in
A. Sunflower
B. Pistia
C. Pea
D. Wheat

Answer 1

Hint: Roots play the primary role in absorption of water for plants. But in certain types of plants they do not contribute to the absorption of water.

Complete Answer:
Before looking into the answers, let's analyze the functions of roots in plants.
Roots are an important part of all the vascular plants. Their major functions are
1. Anchoring the plant to the ground
2. Absorbing essential mineral nutrients and water
3. In certain plants roots store food

Not every plant has its roots underground. Some of them have roots growing above the ground and these roots are also responsible for absorbing nutrients and supporting them to other structures.

Now, let's look at the options for a correct answer.
- Option A: Roots play a significant role in absorption of water from soil in sunflowers. Other than absorption, roots in sunflowers are so strong, that the sunflower plants are so hard to pull out. Therefore, this is the incorrect option.
- Option B: Pistia is a genus of aquatic plant that belong to the family araceae. It is a perennial monocotyledon with thick, soft leaves that form a rosette. It floats on the surface of water and its roots are hanging submerged beneath the floating leaves. Because of the fact that Pistia is hydrophyte, its roots have an insignificant role in water absorption. Hence, this is the correct option.
- Option C: Roots play a significant role in absorption of water. Other than absorption of water, roots of pea plants contain root nodules, which participate in nitrogen fixation. Therefore, this is the incorrect option.
- Option D: Roots in wheat plants play a significant role in water absorption. They have long roots which provide support and strength to the wheat plants. Therefore, this is the incorrect option.

Thus, the correct option is B) Pistia.

Note: Roots of aquatic plants primarily act as anchorage to the plant. Many plants in the aquatic environment can absorb nutrients through submerged leaves. In free floating plants, roots are very few and they are seen as fine hairs.