Question

Which form of symbiosis benefits one member of the interaction, but neither benefits nor harms the other member? A. Parasitism B. Commensalism C. Sequentialism D. Mutualism E. Natural selection

Short answer

Commensalism

Step-by-step solution

Understand the Definition of Symbiosis

Symbiosis is a close and long-term biological interaction between two different biological organisms. It can be mutualistic, parasitic, or commensal.

Define Mutualism

Mutualism is a type of symbiotic relationship where both organisms involved benefit from the interaction.

Define Parasitism

Parasitism is a relationship where one organism (the parasite) benefits at the expense of the other organism (the host), which is harmed.

Define Commensalism

Commensalism is a relationship where one organism benefits from the interaction, while the other organism is neither helped nor harmed.

Eliminate Incorrect Options

Since mutualism (D) benefits both organisms, it does not fit the criteria. Parasitism (A) harms one organism, so it is also incorrect. Sequentialism (C) is not a recognized form of symbiosis, and natural selection (E) is an evolutionary process, not a form of symbiosis.

Choose the Correct Answer

Based on the definitions, only commensalism fits the criteria where one organism benefits and the other is neither helped nor harmed.

Key concepts

Symbiosis

Symbiosis is an important biological concept that refers to a close and long-term interaction between two different species. These interactions are essential for ecosystems, as they help maintain balance.
Symbiotic relationships can take various forms including mutualism, commensalism, and parasitism. Each type of symbiosis has its characteristics, which highlight the diverse ways organisms can interact.
The term 'symbiosis' originates from the Greek words 'syn' (together) and 'bios' (life), highlighting the close relationship shared by the interacting species. Understanding symbiosis provides insights into how organisms evolve together and the dynamics of ecosystems.

Commensalism

Commensalism is a type of symbiotic relationship where one organism benefits, while the other organism is neither harmed nor helped. This neutral effect on the second organism is what sets commensalism apart from other forms of symbiosis.
Examples of commensalism include:

• Remoras attaching themselves to sharks. The remoras get free transportation and scraps of food, while the sharks are unaffected.
• Birds nesting in trees. The bird gets a safe place to live, but the tree is neither harmed nor benefitted.

Commensalism illustrates how some organisms can exploit environmental niches provided by others, contributing to the diversity of ecosystems.

Mutualism

Mutualism is a symbiotic relationship where both interacting species benefit from the relationship. This type of interaction often leads to co-evolution, where species evolve together to better serve each other's needs.
Examples of mutualism include:

• Bees and flowering plants. Bees get nectar and pollen for food, while plants benefit from pollination.
• Clownfish and sea anemones. Clownfish get protection from predators using the stinging tentacles of anemones, while anemones benefit from the nutrients in clownfish's waste.

Mutualism highlights cooperation in nature, where species can thrive better together than alone.

Parasitism

Parasitism is a symbiotic relationship where one organism (the parasite) benefits at the expense of the other (the host). This creates a dynamic where the parasite depends on the host for survival, often causing harm in the process.
Key examples of parasitism include:

• Ticks feeding on mammals. Ticks get nourishment from the blood of their hosts, while the host can suffer from blood loss and diseases.
• Tapeworms in the intestines of animals. Tapeworms absorb nutrients meant for the host, potentially causing malnutrition for the host.

Parasitism shows how some organisms adopt a strategy of taking advantage of others for their own benefit, illustrating the competitive aspects of ecological interactions.