What are unwanted plants that compete with desirable plants for resources?

Weeds are defined as unwanted plants that grow in spaces where they are not wanted, particularly in agricultural fields, gardens, and landscapes where desirable plants are cultivated. They compete with these desirable plants for essential resources such as sunlight, water, and nutrients in the soil. This competition can hinder the growth and development of the desired crops or vegetation, leading to reduced yields and quality. Managing weeds is a critical aspect of plant science and agriculture, as controlling their growth helps to promote the health and productivity of cultivated plants.

The other options, fungi and bacteria, refer to microorganisms that can be beneficial or detrimental to plant health but do not specifically compete with plants for resources in the same way that weeds do. Chemicals, while they can be used to manage weeds or promote plant growth, are not plants themselves and therefore do not compete for resources. Thus, weeds are clearly the best answer in the context of plant competition for resources.