Day 2 Ecosystems Intro
Watch this video: Generation Genius Symbiosis
Read this article (or click here to have it read to you ) and then answer the questions on your journal page for DAY 2.
Symbiotic Relationships
Symbiosis is a close relationship between two species in which at least one species benefits. For the other species, the relationship may be positive, negative, or neutral. There are three basic types of symbiosis: mutualism, commensalism, and parasitism.
ANSWER QUESTION 1
Mutualism
Mutualism is a symbiotic relationship in which both species benefit. An example of mutualism involves goby fish and shrimp (see the Figure below). The nearly blind shrimp and the fish spend most of their time together. The shrimp maintains a burrow in the sand in which both the fish and shrimp live. When a predator comes near, the fish touches the shrimp with its tail as a warning. Then, both fish and shrimp retreat to the burrow until the predator is gone. From their relationship, the shrimp gets a warning of approaching danger. The fish gets a safe retreat and a place to lay its eggs.
[Figure2]Coevolution often occurs in species involved in mutualistic relationships. Many examples are provided by flowering plants and the species that pollinate them. Plants have evolved flowers with traits that promote pollination by particular species. Pollinator species, in turn, have evolved traits that help them obtain pollen or nectar from certain species of flowers. The flowering plants and the pollinators, such as a bird or insect, both benefit from the relationship.
ANSWER QUESTION 2
Commensalism
Commensalism is a symbiotic relationship in which one species benefits while the other species is not affected. One species typically uses the other for a purpose other than food. For example, mites attach themselves to larger flying insects to get a “free ride.” Hermit crabs use the shells of dead snails for homes. Another example of commensalism involves a whale and barnacles (see the Figure below). The barnacles attach to the whale to gain greater access to food and a secure place to live. The whale is unaffected by the relationship.
[Figure3]ANSWER QUESTION 3
Parasitism
Parasitism is a symbiotic relationship in which one species (the parasite) benefits while the other species (the host) is harmed. Many species of animals are parasites, at least during some stage of their life. Most species are also hosts to one or more parasites.
Some parasites live on the surface of their host. Others live inside their host. They may enter the host through a break in the skin or in food or water. For example, roundworms are parasites of mammals, including humans, cats, and dogs. The worms produce huge numbers of eggs, which are passed in the host’s feces to the environment. Other individuals may be infected by swallowing the eggs in contaminated food or water.
Some parasites kill their host, but most do not. It’s easy to see why. If a parasite kills its host, the parasite is also likely to die. Some parasites may cause relatively minor damage to their host.
ANSWER QUESTION 4
ANSWER QUESTIONS 5-7 while watching this video
When you finish your DAY 2 worksheet, show it to your teacher and ask if you can go to this website..... Food Fight