Biotic Interaction — Set 5

Correct Answer: A. Cuscuta

Cuscuta is a parasitic plant that lacks chlorophyll and relies entirely on its host. It wraps around other plants and absorbs their nutrients through special roots. It is a common weed that can severely damage crops.

Correct Answer: B. Amensalism

This is a form of amensalism where the secondary species is harmed by the chemical environment. The primary species is not benefited or harmed by this effect. This often happens in aquatic environments with waste accumulation.

Correct Answer: C. Commensalism

The correct answer is 'Commensalism'. The epiphyte gains better access to sunlight and air while the tree is unaffected. This is a standard example of a (+, 0) interaction in tropical forests. Epiphytes do not take nutrients from the host tree's vascular system.

Correct Answer: C. Parasitoid

Parasitoids are a unique group, mostly insects, that are fatal to their hosts. They lay eggs on or in a host, and the developing larvae consume the host's body. This interaction is common in biological pest control.

Correct Answer: B. Herbivory

Herbivory is the consumption of plant material by animals. It is a specific type of predation that involves primary consumers. Plants have evolved thorns and toxins to survive such interactions.

Correct Answer: A. Mutualism

The anemone provides protection to the crab, while the crab provides mobility and food scraps. This is a beneficial relationship for both species. It is an example of non-obligate or facultative mutualism.

Correct Answer: C. Nutrient absorption

The correct answer is 'Nutrient absorption'. Mycorrhizal fungi extend the root system's reach to absorb phosphorus and water. In return, the plant provides the fungi with sugars produced during photosynthesis. This mutualism is essential for the health of over 90% of plant species.

Correct Answer: A. Neutralism

Neutralism is represented by the symbols (0, 0) indicating no interaction effect. While rare in nature, it is a starting point for studying biological relationships. Most organisms have at least some indirect impact on their neighbors.

Correct Answer: B. Ectoparasite

Ectoparasites like fleas and ticks feed on the host from the outside. They are often vectors for various infectious diseases. They have specialized limbs to attach themselves firmly to the host's body.

Correct Answer: C. Competitive Exclusion

The correct answer is 'Competitive Exclusion'. This principle states that two species competing for the same limited resource cannot coexist. One will eventually outcompete and eliminate the other. This concept is fundamental to understanding community structure and niche theory.