Name________________________________ Hour_______

Chapters 5.1 and 5.2 Guided Notes and Practice Populations A population is a group of organisms of a single species that lives in a given area. The area inhabited by a population is called its ________________ _____________. A population’s range can vary enormously in ____________, depending on the _____________. Population _______________ refers to the number of individuals per unit area. Individuals in a population are either spaced out _____________ , ________________, or ______________. A population’s growth rate determines whether the size of the population ______________, _________________, or stays the __________. Populations also have an age structure, or the number of _________ and __________ of each age a population contains. Population Growth A population may _________ if individuals move into its range from elsewhere, which is called _________________. The opposite of immigration is ________________,, where a population ________________in size when individuals move out of the population’s range. When there is _______________ resources, a population will grow _____________ . This exponential growth means that the ______________ a population gets, the ______________ it grows. This growth is shaped like a _____ on a graph. When there is not unlimited resources, _________ growth happens. Logistic growth is shaped like a _____ on a graph.Logistic growth happens when:

1. A _______________ grows rapidly 2. Growth _________ 3. The growth __________

The growth will stop at a certain population size. This population size is called the _____________ ___________ . The carrying capacity is the _____________ number of individuals of a particular species that a particular environment can __________. So Why Does Logistic Growth Happen? Populations show logistic growth (“S” shape) because of limiting factors exist in the environment. Limiting factors are factors that control the growth of a population. There are several kinds of limiting factors that are depending on how big the population is; such as competition, predation, parasitism, and disease. Others, like ___________

_____________ and __________ weather, do not depend on how _______ the population is. Acting separately or together, limiting factors determine the _____________ ______________ of a population. Density­Dependent Limiting Factors Density­_____________ limiting factors happen when the population density, or the number of organisms in a certain space, reaches a _________ level. These factors do not affect __________ populations. Examples of density­dependent limiting factors are ____________ , predation, ____________ , parasitism, and ______________. Competition depends on the ________ of a population because the _________ individuals living in an area, the __________ they use up the available _______________. The size of the predator and prey _______________ can affect the size of each other. The populations of predators and prey can __________ up and down at times. Herbivores and plants follow the same _____________. _______________ and ______________ depends on population size because the ______________ the host population, the more easily parasites and disease can _____________ from one host to another. Density­Independent Limiting Factors Density­______________ Limiting Factors affect _____ populations in similar ways, regardless of population ________ and _____________. Unusual weather such as hurricanes, droughts, or __________, as well natural disasters like ____________ can act as density­independent limiting factors.

Guided Practice 1.What is a geographic range? 2. How is population density different than geographic range? 3. What are the three ways individuals in a population can be distributed? 4. Why does knowing the age structure of a population important?

A B 5. Using the image above, what process is occurring when the beetle is moving into Population A? Is Population A increasing or decreasing? 6. Using the same image, what process is occurring when the beetle is leaving Population B? Is Population B increasing or decreasing?

7. Is the above image an example of exponential or logistic growth? Why? 8. In the above image, is there unlimited or limited resources in the environment?

9. Is the above image an example of exponential or logistic growth? Why? 10. What is the carrying capacity of the population in the above image? 11. If two species are competing for the same resource, what will happen to the carrying capacity of the two species? 12. Let’s say there are bobcats in the tundra that eat rabbits. What will happen to the population growth and carrying capacity of the rabbits if the bobcat population suddenly decreased? 13. Let’s hypothetically say the sun burned out and there was no light. What would happen to the carrying capacity of herbivores that feed on plants over time? 14. What are examples of density­independent limiting factors and explain why they are density­independent