Problem 22 - Biology E/M

Question

Choose from the terms below. (A) Mutualism (B) Parasitism (C) Commensalism (D) None of the above (E) A, B, and C One organism benefits; the other organism is not affected by the first organism

Step-by-Step Solution

Answer

Commensalism (C)

Step 1: Understanding the Terms

The first step to solving this exercise is to understand the given terms. Mutualism (A) is a relationship where both organisms benefit. Parasitism (B) is where one organism benefits at the expense of the other. Commensalism (C) is where one organism benefits, and the other is neither helped nor harmed. 'None of the above' (D) is when none of these relationships apply. 'A, B, and C' (E) suggests all options are applicable.

Step 2: Analyzing the Scenario

The scenario describes a relationship where one organism benefits, and the other is not affected. This fits the definition of commensalism, where one benefits while the other is unaffected.

Step 3: Choosing the Correct Term

According to the definitions, commensalism (C) matches the condition described in the problem: 'One organism benefits; the other organism is not affected by the first organism.' Therefore, the correct answer is (C) Commensalism.

Key Concepts

Mutualism

In the natural world, mutualism is a type of symbiotic relationship where both participating organisms gain benefits. This form of interaction is mutually advantageous, enhancing the survival and reproduction chances of both species involved.

Here are some classic examples of mutualism:

• Bees and flowers: Bees collect nectar from flowers to make food, while simultaneously helping in the pollination of those flowers. This exchange benefits both the bees and the plants.
• Clownfish and sea anemones: Clownfish live among sea anemones and find protection from predators, while they help clean the anemones and provide nutrients through their waste.

Mutualism often plays a crucial role in ecosystems. It supports biodiversity and helps in the functioning of ecological networks. In mutualistic relationships, both parties are dependent on each other, showcasing nature's intricate web of life.

Parasitism

Parasitism represents a relationship where one organism, known as the parasite, benefits at the cost of the other, referred to as the host. The parasite might derive nutrients, shelter, or other benefits, while the host typically suffers harm or detriment.

Consider these examples of parasitism:

• Ticks on mammals: Ticks attach to skin, feeding on the blood of mammals. This can weaken the host and sometimes transmit diseases.
• Tapeworms in intestines: Tapeworms absorb nutrients from the host's food in the intestines, depriving the host of essential nutrients and causing health issues.

Parasites often evolve specialized traits to efficiently exploit their hosts, and the hosts may evolve defenses to avoid or mitigate the parasite's impact. Parasitism is a strong driving force in evolution, leading to a dynamic arms race between parasite and host.

Commensalism

In commensalism, one organism benefits while the other remains unaffected. This relationship does not confer any particular advantage or disadvantage to the host, making it unique among symbiotic relationships.

Examples of commensalism include:

• Barnacles on whales: Barnacles attach themselves to the surfaces of whales, gaining transportation to nutrient-rich waters without affecting the whale.
• Remora fish and sharks: Remoras use suction to attach to sharks, gaining access to food scraps and safe travel while the shark is neither helped nor harmed.

Commensalism can result from direct interactions, like those described, or indirect interactions, where a species benefits from the environment created by another species. Understanding commensal relationships helps to appreciate the subtleties of ecological interactions and how ecosystems are delicately balanced.