You currently have JavaScript disabled on this browser/device. JavaScript must be enabled in order for this website to function properly.

ZingPath: Organisms and Their Relationships


Searching for

Organisms and Their Relationships

Learn in a way your textbook can't show you.
Explore the full path to learning Organisms and Their Relationships

Lesson Focus



Learning Made Easy

You will be introduced to parasitism and you get to conduct an experiment combining two species in a parasitic relationship.

Over 1,200 Lessons: Get a Free Trial | Enroll Today

Now You Know

After completing this tutorial, you will be able to complete the following:

  • Explain that, in parasitism, one organism benefits and the other is harmed.
  • Identify organisms that are in parasitic relationships.
  • Differentiate between the following forms of symbiosis; mutualism, commensalism, and parasitism.

Everything You'll Have Covered

When two species live in close, direct contact with organisms from other species, they may have a symbiotic relationship. Some of these relationships benefit both species (mutualism), sometimes one species benefits and the other is unaffected (commensalism), and in other instances one species benefits at the other's expense (parasitism).

This tutorial focuses on parasitism. In parasitism, the organism that benefits is called the parasite and the organism that is harmed is called the host. The parasite gets nourishment from its host, which is weakened in the process. At times, a host organism becomes so weak that it dies. The most successful parasites, however, do not kill their hosts. Examples of parasitic relationships include sharks and lampreys, ticks and dogs, and mistletoe and trees.

In nature, all types of different species live in close proximity to each other. Because of this, many different types of relationships are formed. These relationships of species living and interacting with each other are sometimes referred to as symbiosis.

Similarly, in our "human world," there are many different types of relationships. Just like different types of symbiotic relationships in the natural world, some are mutually beneficial, some are competitive, and there are some in which one party is harmed. In parasitism, one organism is helped while the other is harmed. There are many examples of organisms that are parasitic to humans-certain bacteria, ticks, tapeworms, etc.

Tutorial Details

Approximate Time 20 Minutes
Pre-requisite Concepts Students should be familiar with these terms: commensalism, ecosystem, mutualism, organism, and species.
Course Biology
Type of Tutorial Concept Development
Key Vocabulary commensalism, ecosystem, harm