Question

Which of the following is also called unwanted plants?
A. Weeds
B. Shrubs
C. Grasses
D. Feeds

Answer 1

Hint:
Unwanted plants are those plants that are considered undesirable in a particular circumstance, basically those plants that have grown in the wrong place. Such plants have no botanical significance. In some cases, it can be said that these plants have no economic significance as well. They get advantage over desirable plants or crops that they can grow more easily and quickly.

Complete step by step answer:
Plants that are unwanted to humans are termed as weeds. Such plants are invasive and inhabit the areas where they grow, extensively. The weeds are considered unwanted because of the competition that they provide to the economically beneficial crops or plants. These weeds compete with the plants by interfering with their food requirements. Weeds compete with the desired plants for their resources, they take up the minerals and nutrients that those plants need from the soil.
Shrubs- These are small plants having hard and woody stems, like a rose plant.
Weeds fight for direct sunlight which the plant receives, water and the space for growth. Weeds after growing to a certain extent start providing opportunity to some host organisms like vectors and pathogens that infect the desired plants and ultimately leads to the crop failure and degradation of the quality of the product.

Hence here the correct answer will be option (A).

Note:
Weeds also provide both shelter and food to various seed-eating birds and flies that again harm the crops that are useful to humans. The roots of such plants when grown extensively can then damage the roots of the crops or plants present in their close proximity.
One of the examples of the weeds that has grown extensively and devastated the water bodies thus resulting in mortality of water animals is water hyacinth (Eichhornia crassipes), also known as “Terror of Bengal”.