Cornell Notes

Chapter 18:

Interactions of Living Things

Chapter 18: Section 1: Everything Is Connected

Page 434 – 437

1) What is ecology? 1) Ecology is the study of interactions between organisms and their environment.
2) Define biotic. 2) The term "biotic" describes living factors in an environment.
3) Define abiotic. 3) The term "abiotic" describes nonliving factors in the environment.
4) What is a population? 4) A population is a group of individuals of the same species that live together in the same area at the same time.
5) What is a community? 5) A community is all of the populations of different species that live and interact in an area.
6) What is an ecosystem? 6) An ecosystem is a community of organisms and their nonliving environment.
7) Define biosphere. 7) The biosphere is the part of the Earth where life exists.
8) Distinguish between the biotic and abiotic environment. 8) An environment consists of two parts---all of the living organisms and all of the physical factors (water, soil, light, temperature, etc.) that affect the living organisms in that area.
9) Explain how populations, communities, ecosystems, and the biosphere are related. 9) The environment can be arranged into different levels:

1-the individual organism

2-a group of that same organism (a population)

3-several different populations (forming a community)

4-several different communities (forming an ecosystem)

5-all ecosystems (forming the biosphere)
10) Explain how the abiotic environment relates to communities. 10) A community, which consists of the different populations of an area, combined with the abiotic environment, the physical environment, make up the ecosystem.
11) Give two examples of biotic and abiotic factors in the salt-marsh ecosystem. 11) BIOTIC                               ABIOTIC

    Cordgrass                             salt water

    Periwinkle                             snail tide
12) List the five levels of environmental organization from the smallest group to the largest. (See page 435) 12) The five levels of environmental organization, from smallest to largest are:

1-organism

2-population

3-community

4-ecosystem

5-biosphere
13) Using the salt-marsh example, distinguish between population, community, ecosystem, and biosphere. 13) A population of seaside sparrows lives in a community, which includes all the populations around it. This community lives in a salt-marsh ecosystem, which is defined by a certain geographical location and a certain climate. This ecosystem exists within the biosphere, which is the part of Earth where life exists, including our atmosphere.
14) What would most likely happen in the salt-marsh environment if the cordgrass were to suddenly die out? 14) All of the other organisms in the salt-marsh ecosystem depend, either directly or indirectly, on cordgrass for food. Without cordgrass, all of the other organisms would probably die out or move into other areas.
15) A caterpillar, a deer, and a rabbit all want to drink from the same puddle, eat the same plant, and bask in the same spot of sunshine. Are they competing members of a population? Why or why not? 15) No; each is a different species. Therefore, they are competing members of a community---not a population.
16) Using the salt-marsh example, explain why ecologists state that saving a large animal, such as the heron or egret, can also save an ecosystem. 16) The heron and the egret can survive only if the salt marsh remains intact to provide shelter and food for the organisms that the birds need to eat.
17) List four abiotic and four biotic factors in your neighborhood/yard. Describe how the biotic factors change when the abiotic factors change. 17)

BIOTIC                                     ABIOTIC

(living)                                     (physical)
Chapter 18: Section 2: Living Things Need Energy

Page 438 – 443

1) What is a producer? What is its function in an ecosystem? 1) A producer is an organism that makes its own food usually by using the energy from sunlight to make sugar. The function of producers is to provide a source of energy for primary consumer (herbivores). 
2) Define consumer? What is its function in an ecosystem? 2) A consumer is an organism that eats producers (herbivore) or other consumers (carnivore) for a source of energy. The function of consumers is to provide a source of energy for secondary consumers (carnivores) and for decomposers.
3) What is a decomposer? What is its function in an ecosystem? 3) A decomposer is an organism that gets energy by breaking down the remains of dead organisms or animal wastes and consuming or absorbing the nutrients. The function of a decomposer is to return nutrients to the soil, air, or water that are in a simpler form for other organisms to use. They are nature’s recyclers.
4) Define herbivore. Give an example. 4) A herbivore is a consumer that eats plants (producers). Some examples of herbivores are grasshoppers, gophers, prairie dogs, bison, and pronghorn antelope.
5) What is a carnivore? Give an example. 5) A carnivore is a consumer that eats animals (other consumers). Some examples of carnivores are coyotes, hawks, badgers, and owls. 
6) Define omnivore. Give an example. 6) An omnivore is a consumer that eats a variety of organisms; both plants and other animals. An example of an omnivore is most humans. 
7) What is a scavenger? Give an example. 7) Scavengers are organisms that feed on the bodies of dead animals. Several examples of scavengers are vultures, crayfish, snails, clams, crabs, and worms.
8) Define food chain. 8) A food chain is a diagram that represents how the energy in food molecules flows from one organism to the next.
9) What is a food web? 9) A food web is a complex diagram representing the many energy pathways in a real ecosystem.
10) Explain the difference between a food chain and a food web.  10) A food chain is a simple illustration of the flow of energy from one organism to the next. Few organisms eat just one kind of organism, so a food web is a more accurate representation of the flow of energy in an ecosystem. Energy will only flow in one direction; the rabbit will not eat the hawk.
11) What is an energy pyramid?  11) An energy pyramid is a diagram shaped like a triangle that shows the loss of energy at each level of the food chain. More energy is available at the base of the triangle than at the top of the triangle. The amount of available energy is reduced at higher levels of the triangle because most of the energy is either used by the organism or given off as heat. Only the energy stored in an organism’s tissues can be used by the next consumer.
12) What is a habitat?  12) A habitat is the environment where an organism lives.
13) What is a niche?  13) A niche is an organism’s way of life and its relationships with its abiotic and biotic environments.
14) Draw and label a food web. Explain how energy flows through your food web. 14) FOOD WEB:

The producers in this food web are plants.  Rabbits, squirrels, mice, seed-eating birds, and herbivorous insects eat the plants.  Spiders and predaceous insects eat the herbivorous insects.  Insectivorous birds and toads eat the spiders and predaceous insects.  Foxes, hawks, owls, and snakes eat the rabbits, squirrels, mice, seed-eating birds, insectivorous birds, herbivorous insects, predaceous insects, and toads.
15) Explain the difference between an organism’s habitat and its niche.  15) An organism’s niche (way of life) includes its habitat (where it lives), its food, its predators, and the organisms it competes with. An organism’s niche also includes how it affects and is affected by the abiotic factors in its environment such as temperature, water, and light.
16) Where is the most energy found in an energy pyramid?  16) The area with the most energy in an energy pyramid is the base of the pyramid.
17) How might an omnivore be a link both at the beginning of a food web and near the end?  17) An omnivore can be at the beginning of a food web because it eats plants. It can be near the end of a food web because it also eats other consumers.
18) Write an eight step recipe for a decomposer’s dinner. The first ingredient is sunlight. List seven more. 18) 1-SUNLIGHT J ... THIS ONE IS FOR YOU!!!

      2-

      3-

      4-

      5-

      6-

      7-

      8-

Chapter 18: Section 3: Types of Interactions

Page 444 – 449

1) What is a limiting factor? Give several examples. 1) Limiting factors are factors that slow or halt the growth of a population. Some examples of limiting factors are the amount of food, water, shelter, sunlight, or space an area has. When one of these factors becomes scarce, the population of organisms will either begin to die out or some of the organisms will move out of the area.
2) Define carrying capacity. 2) The largest population that a given environment can support over a long period of time is known as the environment’s carrying capacity. When the population exceeds the carrying capacity, limiting factors will cause the population to decrease.
3) What is competition? List the two types of competition. 3) Competition is when two or more individuals or populations try to use the same limited resource such as food, water, shelter, sunlight, or space. Competition can occur within a population or between populations of different species.
4) Explain the difference between the two types of competition. 4) Competition within a population occurs when members of the same species compete with each other over the same limited resource. Competition between populations occurs when members of different species compete with each other for the same limited resource. 
5) Define prey. 5) Prey is defined as an organism that is eaten by another organism. 
6) Define predator. 6) Predator is defined as an organism that eats other organisms. 
7) Give examples of prey : predators. 7) Examples of prey : predators are

                      Worm : bird

                      Insect : spider

                      Bird : cat

                     Antelope : lion

 
8) What is symbiosis? List the three types of symbiotic relationships. 8) Symbiosis is a close, long-term association between organisms of two or more species. The three types of symbiosis are mutualism, commensalisms, and parasitism. 
9) Define mutualism. 9) Mutualism is defined as a symbiotic relationship in which both organisms benefit. One example of mutualism is the bacteria that live in the human intestines. The bacteria receive food from the human host while the human host receives vitamins from the bacteria.
10) Define commensalisms.  10) Commensalism is defined as a symbiotic relationship in which one organism benefits and the other is unaffected. An example of commensalism is the remora attached to a shark. The remora benefits by feeding on scraps of food left by the shark while the shark is unaffected by the remora.
11) Define parasitism.  11) Parasitism is defined as a symbiotic association in which one organism benefits while the other organism is harmed. An example of parasitism is the tomato hornworm and the wasp. The wasp will lay eggs on the caterpillar. When the eggs hatch, the young wasps will burrow into the caterpillar’s body and eat the caterpillar alive. The wasps benefit while the caterpillar is harmed.
12) What is a parasite?  12) A parasite is an organism that feeds on another living creature, usually without killing it.
13) What is a host?  13) A host is an organism on which a parasite lives.
14) Define coevolution and give an example.  14) Coevolution is defined as the long-term changes that take place in two species because of their close interactions with one another.
15) Explain the difference between mutualism and coevolution.  15) Mutualism is a close, long-term association between two organisms in which both benefit. Coevolution is the gradual change in two organisms’ physical characteristics as a result of a symbiotic relationship.
16) Organize the following terms into a concept map: competition, predator, individuals, population, symbiosis, commensalisms, prey, mutualism, interactions.

(YOU MAY USE MORE THAN ONE CONCEPT MAP!)

 

 CONCEPT MAP:

                 SEE EXAMPLES ON PAGE 786!