Symbiosis: Types of Relationships

Transcription

1 Symbiosis: Types of Relationships

2 What is symbiosis? Symbiosis is a situation where two types of organisms live closely together. If the two organisms are separated, one (or BOTH) of them will die! (either immediately, or the population will over time)

3 Why live together? There is always competition within an ecosystem for food, space and resources. In order to survive, each organism occupies a NICHE, or specific role. Organisms can avoid spending energy on competition by forming a relationship with another organism they can share the same space and food supply.

4 Predator/Prey Relationship Predator: Hunts or kills other organisms for food. Prey: Animals that are food for other organisms. Top Predator: Are not prey for any other organisms.

5 Predator/Prey Relationship Predation is a strong, selective pressure that drives prey organisms to find ways to avoid being eaten. Prey organisms that are difficult to find, catch or consume are the ones that will survive and reproduce. The result is that over time, prey organisms have developed a stunning array of strategies to avoid being eaten ADAPTATIONS.

6 Examples of Predator/Prey Snowy Owls and Lemmings Lemming populations go through cycles of growth and decline. When they are large, they eat all the moss and the population starves. This affects the snowy owls they will only reproduce if the lemming populations are large enough for the owls to feed themselves and their chicks.

7 Examples of Predator/Prey Top Predators and White Tailed Deer In Michigan, all the top predators, such as the grey wolf, cougar, and American black bear, have dwindling populations. Without these predators, the white tailed deer population has grown so large that there is not enough food for all the deer. The growing human population has also decreased the amount of natural habitat for the deer. The Michigan state government allows human hunting of deer to help limit the population size and prevent death by starvation.

8 Mutualistic Relationship Mutualism is where both organisms BENEFIT from the relationship.

9 Example of Mutualism Oxpeckers and African Rhinos A type of bird, called oxpeckers (or tick birds), rides upon the back of African rhinos. The oxpeckers protect the rhinos from parasites by eating ticks off the rhinos. The rhinos give the birds a place to live and something to eat.

10 Example of Mutualism Acacia Plant and African Ants Another example involves the acacia plant and african ants. The ants act as a defense mechanism, protecting the plant from other insects or animals. The plant in return provides the ants with precious nutrients that have no other purpose other than to help the ants.

11 What is Commensalism? Commensalism is a relationship between two organisms where one benefits and the other is unaffected.

12 Example of Commensalism Barnacles and Whales Barnacles are sedentary creatures, so adults attach themselves to whales, who transport them to areas where food is available. The barnacles do not affect the whales in any way.

13 Example of Commensalism Orchids and Trees Orchids are plants with beautiful flowers that are found in the rainforest. They have adapted to grow on top of other trees and larger plants in order to get more light to perform photosynthesis. They do not harm or affect the trees they grow on they do not take the tree s nutrients.

14 What is Parasitism? Parasitism is a relationship where one organism is benefited, and the other is harmed in some way.

15 Example of Parasitism Lice and Humans Lice live exclusively on the scalps of humans, and they feed off human blood. In return, they cause a rash and irritation to the human host.

16 Example of Parasitism Caterpillar Wasps and Caterpillars Caterpillar wasps lay their eggs inside or on a caterpillar. When the eggs hatch, they feed on the caterpillar, causing it to die. Some plants actually release secretions that attract caterpillar wasps when caterpillars start eating their leaves.

17 Which type of symbiosis is being shown? The human intestine contains many different kinds of bacteria. The bacteria break down and process food and help fight disease, in turn they get a place to live without any predators or competition from other bacteria for food.

18 Which type of symbiosis is being shown? The Great Burdock is a plant that produces seeds in a hooked casing. This casing allows the seed to hook onto the fur of animals passing by without hurting them, and the animals spread the seed to new locations.

19 Your Task: Animals gain and adapt their physical features over millions of years, but our task today is going to cut down that time just a little - you are going to design an animal which is perfectly suited to its environment. Background Information: It is the future, the year 3000, and it is now possible for humans to build planets, and genetically engineer or create plants and animals to live on that planet. You are one of the scientists working on the animals, and it is your job to design and create animals which will be perfectly suited to their environment on this new planet. Task: You need to pick one of the following environments on your sheet, and create organisms that will survive together in a symbiotic relationship on that planet.