Lesson 9 Biology Engage: Biological Relationship Tic-Tac-Toe Host Mutualism Prey Competition Parasitism Predation Commensalism Predator Symbiosis ______________________________________________________________________ Symbiosis Commensalism Prey Parasitism Host Competition Predation Mutualism Predator © 2013 Region 4 Education Service Center STAAR™ Achievement Series for Science Lesson 9 Biology Engage: Biological Relationship Tic-Tac-Toe Predation Symbiosis Predator Parasitism Competition Host Prey Mutualism Commensalism Prey Commensalism Symbiosis Competition Mutualism Predation Parasitism Predator Host STAAR™ Achievement Series for Science © 2013 Region 4 Education Service Center Lesson 9 Biology Explore: Predator-Prey Simulation Organism Yarn Color Food Source cricket green grass (popcorn) frog yellow crickets hawk red frogs fox brown frogs Trial Time of Trial Animal with Animal with Greatest Survival Least Survival 1 Equal distribution 2 Population change: Increase the number of frogs 3 Population change: Decrease the number of frogs and increase the number of crickets 4 Population change: Increase the number of hawks and decrease the number of frogs Questions 1. What animal(s) did you play? Describe what you did as the animal(s) to increase your chance of survival. 2. What happened when the population changed and there were more frogs in the ecosystem? 3. What happened when the population changed and there were fewer frogs in the ecosystem? 4. What occurred when the population changed, the hawk population increased, and the number of frogs decreased? 5. What if you survived but were not able to get five pieces of popcorn? How does this translate to what actually happens within an ecosystem? © 2013 Region 4 Education Service Center STAAR™ Achievement Series for Science Lesson 9 Biology Explain Part 1: Predator-Prey Relationships Identify the role and the relationship between the organisms in the Explore activity using the appropriate vocabulary words from the Engage activity. Create a definition of each of the vocabulary words in your own words with your partner. In your science notebook, record your definitions and the answers to the questions below. Questions In the Explore activity: 1. What is the role of the frog in regards to the cricket? 2. What is the role of the frog in regards to the hawk? 3. What is occurring between the hawk and the fox? 4. What is the relationship between the grass (popcorn) and the cricket? STAAR™ Achievement Series for Science © 2013 Region 4 Education Service Center Lesson 9 Biology Explain Part 2: Symbiotic Relationships Many species in an ecosystem share close relationships with other species. When an organism shares a close relationship it is known as symbiosis. There are different types of symbiotic relationships. In some relationships, the interactions between organisms are beneficial to both species while in others, one species may gain but the other has no known effect or is harmed in the interaction. Mutualism When a relationship between two organisms is beneficial to both organisms, the relationship is defined as mutualism. For example, ants routinely milk the honeydew secretions from aphids (insect) for a food source and, in return, the ants protect the aphids from predators. Both organisms benefit from the interaction. Commensalism In other organism interactions, one species may benefit from the relationship but the other species neither benefits nor is harmed. This type of relationship is commensalism. An example of a communalistic relationship can be seen between the remora and larger animals, such as whales or sharks. Remora are equipped with a suction disk on the back of their heads and “catch a ride” on the larger animals. Whales and sharks tend to be messy eaters, so when food from the larger animal floats by, the remora collects the scraps. The remora gets food, but the larger animal has no benefit and is not harmed in the process. Parasitism A third type of relationship between organisms is parasitism. In a parasitic relationship, one organism benefits and the other is harmed. The parasite feeds off a host, an organism in which a parasite resides. The relationship may even cause death to the organism. Plasmodium malariae is a parasite that is transferred from animal to animal by mosquitoes. Once the parasite enters the host animal, it attacks and destroys the red blood cells for a food source. In return, the host animal develops malaria, suffering chills, fevers, sweats, and even death. © 2013 Region 4 Education Service Center STAAR™ Achievement Series for Science Lesson 9 Biology Explain Part 2: Symbiotic Relationships Activity Instructions: Read each passage below with your partner and interpret the relationship of the pair of organisms. If the organism benefits from the interaction, place a plus (+) sign in the box. If the organism is unaffected from the interaction, place a zero (0) in the box. If the organism is harmed by the interaction, place a minus (–) sign in the box. If the organism dies from the interaction, place an X in the box. Identify the relationship between the organisms in the space provided. 1. The cattle egret is a bird that forages in the fields alongside livestock (cattle and horses). As livestock graze, their movement in the grass stirs up the insects that live in the grass. The cattle egrets eat the insects. The livestock are not affected by the interaction. Egret (bird) Livestock Relationship: 2. The cleaner fish cleans inside of the mouth of a Moray Eel. The fish eats the particles that are inside the eel’s mouth and obtains food. The eel does not eat the fish, but does get a clean mouth. The eel provides protection to the small fish from its natural predators. Fish Moray Eel Relationship: 3. Many species of birds fly close to the surface of the water in search of food. If the bird gets too close to the water, it leaves itself vulnerable to organisms living in the water, such as sharks. The sharks will come to the surface and attack the bird, dragging it beneath the water. Bird Shark Relationship: STAAR™ Achievement Series for Science © 2013 Region 4 Education Service Center Lesson 9 Biology 4. Flesh-eating bacteria known as Streptococcus pyogenes consume the flesh of humans as a food source. The bacteria are able to enter an open wound on the surface of the skin. If the immunity is weakened, the bacterium releases toxins that destroy the skin and soft tissue. Bacteria Human Relationship: 5. In order to move, a pseudoscorpion will catch a ride on insects such as a fly or beetle. The pseudoscorpion gets to where it is going and the fly or beetle is unaffected by the interaction. Pseudoscorpion Fly/Beetle Relationship: 6. Downy mildew is an oomycete, a protist that infects the vines forming plants and crucifers. The oomycete consumes the plant tissue as a food source. The plant forms brown spots on its leaves, which then wither and fall off. Mildew Plant Relationship: © 2013 Region 4 Education Service Center STAAR™ Achievement Series for Science Lesson 9 Biology Elaborate: Biological Relationship Scenarios Scenario 1 Aphids are small insects that feed on the sap of phloem vessels in plants and are often referred to as tree lice. They are most commonly found in temperate climates where they are among the most destructive insects to cultivated plants. In order to control the population of aphids without the use of pesticides, farmers and gardeners will introduce ladybugs to the area. A ladybug can consume up to 1,000 aphids in 1 day. The ladybugs get a food source and the plant is rid of the aphids. Identify the type of relationship shared by the organisms in the above passage. Scenario 2 The sloth is a tree-dwelling animal that lives in the jungles of Central and South America. It lives on a diet that mainly consists of leaves and insects. Sloths have a greenish shaggy coat that contains grooves where two types of blue-green algae make a nice, comfortable home. This provides the sloth with the greenish coat that camouflages it from its predators, and the photosynthetic algae are able to get closer to the Sun when attached to the sloth. Identify the type of relationship shared by the organisms in the above passage. Scenario 3 In sub-Saharan Africa, oxpeckers (a kind of bird) land on the backs of large animals, such as cattle, rhinos, and zebras, where it feeds on ticks, the botfly, dead skin, blood, sweat, mucus, insects, infected wounds, earwax, and other parasites. Oxpeckers provide the animals with grooming and remove unwanted pests. In the presence of danger, the oxpecker also flies upward and screams a warning that alerts the animal. Recent research may shed new light on the relationship between the oxpecker and large animals. It was previously thought that the animals’ wounds healed faster when the oxpecker cleaned the wounds, but this may not be the case. It has been observed that oxpeckers prolong the healing of wounds and also create new wounds when removing earwax. Since the primary food source is ticks and ticks are full of blood, the primary target of the oxpecker may be blood. If the oxpeckers share the relationship in the first paragraph with the livestock, what type of relationship is being exhibited? If the relationship is what is described in the second paragraph, what type of relationship do they share? © 2013 Region 4 Education Service Center STAAR™ Achievement Series for Science Lesson 9 Biology Scenario 4 Amphibians such as frogs and toads often feed on adult beetles. It was once believed that they also fed on the beetle larvae, but when more closely studied, a different behavior was observed. The beetle larvae use a unique movement of their antennae and formidable-looking mandibles to draw the attention of amphibians. The amphibian attacks and the larvae almost always avoid the protracted tongue.