Relationships

Living together = Symbiosis

 

 

 

Symbiosis means living together. It is an interaction between 2 organisms where at least one of these organisms benefits. The benefit may be in the form of :
-food,
-transport,
-protection,
-grooming,
or all of the above.


 

 

Take the green ant (Oecophylla smaragdina) for example, this aggressive ant nests in trees where it provides protection from insects that harm the tree. In return the tree provides nourishment for the ants in the form of nectar.

The picture shown on the right of a flame tree in Arnhem Land, Australia, clearly shows how green ants nest in the foliage of trees. Click to see a detailed image.

 

Green ants use the foliage of the plant to build nests. These nests are made by joining leaves together using a silky substance produced by their larvae.
If the leaves are not close enough to be bound, ants form ant chains to pull the leaves close together.

Click to see a more detailed image

 
Some Australian native trees produce very exotic flowers, as shown on the right the flower of the Flame tree, with nectar to entice a beneficial relationship with particular insects.
Click to see a detailed image

There are three different types of symbiotic relationships, these include:
- commensalism - where one organism benefits but the other is neither harmed nor does it benefit.
- parasitism - where one organism benefits while the other is harmed
- mutualism - where both organisms benefit.

An example of mutualism is the relationship between bees and flowering plants. Both organisms benefit in the relationship, the bee derives nectar and pollen from the plant while the plant becomes cross fertilised by the bees.

On the right is a picture of an Australian native bee, known as the blue banded bee (Amegilla cingulata) Click to see a detailed image.
The relationship between the barnacles and the whale is an example of commensalism, where the barnacles benefit by being transported to food rich regions of the ocean while the whale is not harmed in any way in this relationship.

 

 
Epiphytes are plants that grow on other plants in a non-parasitic relationship. Although an epiphyte derives its moisture and nutrients independently of its host it benefits by been high above the ground out of reach of herbivores and where there is more sunlight. The host plant does not benefit nor is it harmed. This relationship also is an example of commensalism.

 

Another type of relationship is known as a predator-prey relationship. Simply put, a predator is an organism that eats another organism. The organism being eaten is the prey while the organism eating the other is the predator. For example, a dragonfly will eat flies and therefore the dragonfly is the predator while the fly is the prey.

This predator-prey relationship does not only apply to animals it can also apply to plants such as when a grasshopper eats grass, the grasshopper is the predator while the prey is the grass. Predator-prey relationships evolve over time, where the predator evolves all that is needed to successfully its prey. This may include camouflage, speed or bigger jaws.

Click to see a detailed image of the dragonfly

1) Acacia seeds have a small capsule of sugar on one end. Ants collect the seeds in their nests for the sugar. While in the ant's nest the seeds are safe from bushfires. This relationship evolved over thousands of years and is an example of

 

 

 
2) A tapeworm lives in the intestinal tract of humans. It was fashionable in the 1900s for people to ingest tapeworms so that they can loose weight. The relationship between a human and a tapeworm is best described as because
3) The African black rhinoceros ( Diceros bicornis ) and the oxpecker, or tickbird are shown on the right. The oxpecker feeds off ticks, flies, and maggots that stick to the rhino's hide. This relationship is an example of

 
4) Aphids and sugar ants have a very unusual relationship. The aphids provide sugary honeydew which the ants eat while the ants protect the aphids from predators and parasites. This relationship is one of

 
5) Symbiosis means living together. Which statement is true?
6) Consider the terms symbiosis, parasitism, mutualism and commensalism. Which term includes the other three?
7) A relationship is one between two species that enhances the size of each ones population.
8) Cows, horses and rabbits have no digestive enzymes to break down cellulose. Bacteria, however, in the gut of herbivores, not only break down cellulose, but produce vitamins B and K. This type of relationship can be classified as . Explain why.

 
9) What type of relationship exists between the two animals shown on the right?

 
10) The picture on the right shows a wild bore prepared for cooking. What type of relationship exists? Explain.
11) Bacteria in the large intestine of humans produce vitamin K. This relationship is an example of . Explain why

12) Organism "A" invades the body of organism "B" and lives in the red blood cells. Red blood cell count decreases significantly in organism "B" to the point where organism "B" can not function.
a) Which organism is the host?

b) What is another name for organism "A"?

c) Which term best describes the relationship between A and B? Explain.