1. What are parasites?

2. Unit Standards
5.L.4B.1
Analyze and Interpret data to explain how organisms obtain their energy and classify organisms as producers, consumers (including herbivore, carnivore, and omnivore), or decomposers (such as Fungi, Bacteria insects and molds).
5.L.4B.2
Develop and use models of food chains and food webs to describe the flow of energy in an ecosystem.
5.L.4B.3
Construct explanations for how organisms interact with each other in an ecosystem (including predators and prey, and parasites and hosts).
5.L.4B.4
Construct scientific arguments to explain how limiting factors (including food, water, space, and shelter) or newly introduced organisms can affect an ecosystem.

3. What are parasites?
Some partnerships are harmful for individuals in the relationship.

4. What are parasites?
Parasitism- is a symbiotic relationship where one organism benefits and the other is harmed.

5. What are parasites?
A parasite lives in or on a host organism and benefits from the relationship.
For example, ticks are parasites on dogs and other animals. Ticks use their host’s body for a home and a food source.
A tick attaches itself to a host and harms the host by taking in the host’s blood.
The tick’s host gets no benefit from the relationship.

6. What are parasites?
Some parasites are very harmful for the host organism. Millions of people around the world have parasites called tapeworms.
These worms live inside a person’s intestinal tract.
Tapeworms are more than 70 cm (2 ft.) in length have been found in humans.
Tapeworms can harm their hosts by causing fevers and digestive problems.

7. What are parasites? Another dangerous parasite is a lamprey.
Lamprey are parasitic fish.
They use their sucker-like mouth to attach themselves to other fish.
They harm their host by sucking out its blood and other bodily fluids.

8. What are parasites?
Some parasites are protists, including the species of amoeba that causes a disease called dysentery.
Dysentery amoebas enter the host’s body through contaminated food or water.

9. What are parasites?
The protist that causes sleeping sickness in Africa lives in the bodies of cows and other large animals.
When these animals are bitten by flies, the flies transfer the protists to humans, causing the disease.