IB Species Interactions Past Paper 2019 PDF

Species Interactions  Species Interactions Community: A community is all of the living organisms found in a particular area. When organisms live in communities, they _______ interact consta...

Species Interactions  Species Interactions Community: A community is all of the living organisms found in a particular area. When organisms live in communities, they _______ interact constantly and have a powerful effect on the _________. ecosystem Different types of interactions include: 1. Competition 2. Predation 3. Symbiosis 4. Mutualism 5. Commensalism 6. Parasitism  Competition Competition occurs when organisms of the same or different species: attempt to use the same ecological resource in the same place at the same time. © Amy Brown Science What is a resource? A resource refers to anything required for life. Resources might include: food, water, light, nesting sites, or room to grow. © Amy Brown Science When organisms are competing for the same resource, there is often a ________________. winner and a loser The winner thrives and the loser fails to thrive and/or survive.  Predation is an interaction Predation in which one organism captures and feeds on another organism. The predator is: the organism that does the killing and eating. The prey is: the food organism. Predation is a powerful force in the community. Predation determines relationships in _________ food webs and is a very effective regulator of _____________. population size  Natural selection favors adaptations that make organisms…. …. better suited for their environment. Predators have become more efficient over time by developing _____ (through tools natural selection) that make better predators them ______________. Examples: Snakes have heat sensitive pits to help them locate prey. Predators may have acute senses, fangs, claws, poison, stingers, and sharp teeth. Spiders have webs to catch their prey. Vietnamese Mossy Frog Just as the predator must be highly adapted to catch the food, the prey must have adaptations that help them avoid being captured and eaten.  a) The prey may have the ability to run very fast to escape the predator. b) The prey may be camouflaged to avoid detection. c) The prey may have poisons that are advertised by bright warning colors.  Coral snake Mimicry Mimicry is a form of deception used by the prey as a means of defense against being eaten. In mimicry, a harmless King species resembles a snake poisonous or distasteful species. The king snake is a mimic of the very poisonous coral snake.  The viceroy butterfly mimics the monarch butterfly. Birds avoid eating the Viceroy monarchs due to their very bitter taste. Monarch The viceroy does not have a bad taste, but since it resembles the monarch, birds are reluctant to eat it.  Herbivores are: animals that eat plants. This makes the herbivore a predator on plants. Plants and Herbivores Through natural selection, plants have developed adaptations that protect them from being eaten by animals. Plants may have: sharp spines, thorns, sticky hairs, and tough leaves. Plants may also produce: chemical compounds that are poisonous, or bad tasting. Can you give an example of each of the predator-prey combinations listed in the table below? Predator Prey Example Animal Animal A lion kills and eats a zebra. Animal Plant The zebra grazes on grasses. Fungus Animal Athlete’s foot or ringworm. Bacteria Animal A strep infection. Fungus Plant Blights and mildews. Corn Smut  Symbiotic Relationships between Organisms Symbiosis is a close and permanent relationship between organisms of different species. There are three types of Mutualism symbiotic relationships: Mutualism Commensalism Parasitism Parasitism (ticks) Commensalism  In mutualism: both species benefit from the relationship. These birds eat the ticks on the back of the hippos. Flowers and insects have a mutualistic relationship. The flower provides the insect with ______, nectar and the insect helps the flower to reproduce by spreading ______. pollen  Termites have a particular bacterium that lives in their gut. The bacteria help to digest the wood eaten by the termite, and the termite provides the bacteria with: shelter, warmth, water, and food.  Some mutualistic relationships are so close: that neither species can survive without the other. One such example is the ants that live in the acacia shrubs. The ants nest inside the acacia’s large thorns and receive ____ food from the plant. The ants protect the acacia from: predation by herbivores. Commensalism Commensalism is the relationship between two different species in which: one species benefits from the relationship. The other species is neither harmed nor helped. The large fish seen here is called a triggerfish. The triggerfish is able to move large rocks that create feeding opportunities for the smaller fish. There is no benefit to the triggerfish. Barnacles are mollusks that attach to the skin of whales. hurt the whale nor The barnacle does not ____ help the whale. does it ____ The barnacle is a filter feeder and ________ benefits from the constant flow of water. Parasitism Parasitism is the relationship between: two different species in which one species is helped and the other species is The parasite obtains its nutrition _______ harmed. from the other organism, the host ____. Ectoparasites are….. …..external parasites. They live on their host but __________ do not enter the host’s body. Examples include: Leeches, ticks, fleas, and lice.  Endoparasites are….. …..internal parasites. These live inside _____ the host’s body. Examples include: Some bacteria, some protists, and intestinal worms such as tapeworms.