Mutualism, Commensalism, and Parasitism

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Mutualism, Commensalism, and Parasitism
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Ecologists

• These are people that study the interactions
  between organisms (living things).
• There are many different ways that organisms can
  interact. In some cases, the relationship between
  two living things benefits both organisms. In
  other cases, the relationship benefits one
  organism and does not affect the other organism.
  Other relationships benefit one living thing at
  the expense of the other.

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• http//www.teachertube.com/view_video.php?viewkey
  0a18c07b6b13fd8369a5

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Symbiosis

• A living thing is known as an organism. There are
  millions of different organisms, including
  bacteria fungi, plants, and animals. A
  relationship between two different species is
  known as symbiosis, or a symbiotic relationship.
  Symbiotic relationships exist between plants and
  animals. Bacteria and animals. Fungi and plants,
  and so on.

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Mutualism

• Mutualism is a symbiotic relationship in which
  both organisms benefit. For example, the
  relationship between flowering plants and insects
  often involves mutualism. Insects benefit by
  obtaining nectar or nutrients from a plant. In
  turn, the plant benefits because its pollen is
  carried from one plant to another by insect.
  Flowering plants need to spread their pollen to
  other flowering plants in order to reproduce.
  Therefore, the insect benefits the plants by
  spreading the plants pollen.

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• Another example of mutualism can be seen in the
  relationship between honeybees and the iris,
  which is the state flower for Tennessee.
  Honeybees obtain nectar from the iris. In turn,
  honeybees are well suited to serve as pollinators
  for the iris. Honeybees have tongues that are
  almost 2.5 cm (1 inch) long, making it easy to
  pick up the sticky pollen inside the iris. Pollen
  also sticks to the honeybees hairy body. As
  honeybees travel from iris to iris, they help the
  plant reproduce.

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Commensalism

• Commensalism is a symbiotic relationship in which
  one organism benefits and the other organism is
  not affected.
• The mockingbird, which is the Tennessee State
  bird, exists in commensal relationship with the
  trees and shrubs that it calls home.

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• Mockingbirds build their nests in shrubs and
  trees. They use dead twigs and leaves to build a
  nest, filling it with grass and other items. Each
  mating pair of mockingbirds produces two to three
  broods per season. Mockingbirds benefit from the
  protection that the trees and shrubs provide
  their nests. In contrast, the trees and shrubs
  are not benefited or harmed by the mockingbird
  nests.

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Parasitism

• Parasitism is a symbiotic relationship in which
  one organism benefits at the expense of the other
  (harmed) organism. The organism that benefits is
  known as a parasite. The organism that is harmed
  is called the host. An example of parasitism can
  be seen in the raccoon, which is state wild
  animal of Tennessee.

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• Raccoons are hosts to numerous parasites,
  including one parasites, including one parasite
  that can cause disease in humans.
• The raccoon roundworm lives in a raccoons
  digestive tract. The parasite may burrow into the
  raccoons intestines where it can cause minor
  harm to the raccoon.

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• However, the raccoon roundworm is a threat to
  humans. The microscopic eggs of the parasite are
  shed in raccoon feces. Young children are more
  likely than adults to ingest the eggs because
  they often put unclean objects in their mouths.
  After eggs hatch, the roundworms can travel to
  the brain and muscles, where they can cause
  paralysis or even death.

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• http//www.brainpop.com/science/ecologyandbehavior
  /symbiosis/preview.weml

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Discussion

• Why doesnt the raccoon roundworm normally cause
  life threatening harm to the raccoon?
• What are other examples of symbiosis.