SYMBIOSIS Assignment 35

A long-term, interactive relationship between two different organisms. Definition Symbiosis: A long-term, interactive relationship between two different organisms.

There are 3 types of symbiosis: commensalism, mutualism, and parasitism.

an association between two organisms in which Commensalism an association between two organisms in which one benefits and the other is neither helped nor harmed

an association between two organisms in which Mutualism an association between two organisms in which both benefit

an association between two organisms in which Parasitism an association between two organisms in which one benefits and the other is harmed

What Type ? M Bees fly from flower to flower gathering nectar, which they make into food for their colonies. When they land in a flower, the bees get some pollen on their hairy bodies, and when they land in the next flower, some of the pollen from the first one rubs off, pollinating the plant, so it can reproduce.

What Type ? M Spider crabs live in shallow areas of the ocean floor, and greenish-brown algae lives on the crabs‘ backs, making the crabs blend in with their environment and unnoticeable to predators.

What Type? C The Arctic fox follows caribou while they forage for grasses. The caribou dig in the snow to get the grasses. Once a caribou digs up the soil, the Arctic fox comes and hunts some of the underground mammals that have come closer to the surface due to the digging action of the caribou.

What Type? A certain kind of bacteria (bacteria = plural; bacterium = singular) live in the intestines of humans and other animals. A human’s digestive system cannot digest all of the food a person eats. So, bacteria in the intestines eat the food that the human cannot digest, and the bacteria partially digest it, allowing the human to finish the job. M

What Type? C When horses, cows, and other livestock graze in fields, they tend to stir up and move many insects that have been resting on the grass. The cattle egret then catches the insects and eats them.

What Type? P Tapeworms are segmented flatworms that attach themselves to the insides of the intestines of animals such as cows, pigs, and even humans. They get food by eating the host's partially digested food, depriving the host of nutrients.

What Type? M Oxpecker birds perch on rhinos or zebras and eat ticks that live on their skin. The oxpeckers get food, and the beasts get pest control. Also, when there is danger, the oxpeckers fly upward and scream a warning the rhinos and zebras have learned to trust.

What Type? P Fleas find a host, such as dogs, and bite their skin, suck their blood, and cause them to itch. So, the fleas get food and a warm home, and the hosts get itchy skin and sometimes infections.

What Type? C Remora sharks have an adhesive disk on their dorsal (back) surface that allows them to attach themselves to whales or other large marine animals. Once attached, the sharks feed on the remains, or uneaten scraps, from the other marine animal’s food.

Review What are two key characteristics in defining symbiosis? Who benefits in mutualism? What is commensalism? What is the 3rd type of symbiosis? How is symbiosis different from competition? How does symbiosis help organisms survive? Why do many parasites eventually need new hosts? Why do bacteria and viruses spread easily in a crowded place? What type of symbiosis would best describe a teacher-student relationship? Why?

Review ANSWERS What are two key characteristics in defining symbiosis? long-term & interactive Who benefits in mutualism? both benefit (it’s mutual!) What is commensalism? In commensalism, one participant benefits, and the other is unharmed. What is the 3rd type of symbiosis? parasitism

Review ANSWERS 5. How is symbiosis different from competition? Symbiosis involves working together, but competition is a struggle with others for limited available resources. 6. How does symbiosis help organisms survive? It helps them meet their needs, especially their need for food. 7. Why do many parasites eventually need new hosts? The parasites weaken or kill their hosts. Answers will vary, depending on perceptions!

Review ANSWERS 8. Why do bacteria and viruses spread easily in a crowded place? These parasites can easily find a new host in a crowded place. What type of symbiosis would best describe a teacher-student relationship? Why?