5.2+Limits+to+Growth-+Density+Dependent+Factors

** (AP) Limiting Factors **: **Density-Dependent Factors **: 1 . They become limited when the population density reaches certain level 2. Density-dependent limiting factors include competition, predation, parasitism, and disease.  **1) COMPETITION : ** 1 . Competition among members of the __<span style="font-size: 10pt; font-family: Arial, Helvetica, sans-serif;">same species __<span style="font-size: 10pt; font-family: Arial, Helvetica, sans-serif;"> is a density-dependent limiting factor. The more individuals in a living area, the sooner they use up available resources. <span style="font-size: 10pt; font-family: Arial, Helvetica, sans-serif;"> 2. Comp <span style="font-size: 10pt; font-family: Arial; color: rgb(0, 51, 153);">etition also occurs with members of __different species__. This type of competition is a major force behind evolutionary change. When two species compete for the same resources, both species are under pressure to change in ways that decrease their competition. <span style="font-size: 13pt; font-family: Arial; color: rgb(0, 51, 153);"> <span style="font-size: 10pt; color: rgb(0, 0, 128); text-align: center; display: block;">(**Finches beaks in competition**: http://www.cbu.edu/~seisen/ExamplesOfCompetition_files/image003.gif) <span style="font-size: 10pt; font-family: Arial; color: rgb(0, 51, 153);"> <span style="font-size: 13pt; font-family: Arial; color: rgb(0, 51, 153);">
 * <span style="color: rgb(0, 0, 128);">A <span style="background: yellow none repeat scroll 0% 0%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial;">limiting factor is a factor that causes population growth to decrease
 * <span style="color: rgb(0, 0, 128);">Limiting factors on population
 * 1) <span style="color: rgb(0, 0, 128);">Competition
 * 2) <span style="color: rgb(0, 0, 128);">Predation
 * 3) <span style="color: rgb(0, 0, 128);">Parasitism
 * 4) <span style="color: rgb(0, 0, 128);">Disease
 * 5) <span style="color: rgb(0, 0, 128);">Drought and other climate extremes
 * 6) <span style="color: rgb(0, 0, 128);"> Human disturbances
 * <span style="color: rgb(0, 0, 128);">A limiting factor that depends on population size is called a <span style="background: yellow none repeat scroll 0% 0%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial;">density-dependent factor,
 * <span style="color: rgb(0, 0, 128);">Competition occurs when populations become crowded, organisms compete with one another for food, water, space, sunlight, and other essentials.


 * Helps to control the population of organisms in nature
 * Predation takes place in a <span style="color: rgb(128, 0, 128);">**__predator-prey__** relationship
 * A predator-prey relationship is when one animal kills another animal for<span style="color: rgb(128, 0, 128);"> food . (food chain)
 * These relationships control the size of the population of the organisms because if the population of prey <span style="color: rgb(128, 0, 128);">decreases over time the population of predators <span style="color: rgb(128, 0, 128);">will also decrease . This is because the predators rely on the prey for food.

<span style="color: rgb(236, 65, 183);"> (above: Lion & Zebra..http://www.necsi.org/projects/evolution/co-evolution/pred-prey/lion+zebra.jpg)



(above: Bird & fish : http://www.learner.org/jnorth/images/graphics/d-e/eagle19.jpg)

<span style="font-size: 10pt; color: rgb(153, 0, 204); font-family: Arial; text-align: center;"> //<span style="font-size: 10pt; color: rgb(153, 0, 204); font-family: Arial;">***EXAMPLES*** // //<span style="font-size: 10pt; color: rgb(153, 0, 204); font-family: Arial;">~tapeworms // //<span style="font-size: 10pt; color: rgb(153, 0, 204); font-family: Arial;">~fleas // //<span style="font-size: 10pt; color: rgb(153, 0, 204); font-family: Arial;">~ticks // //<span style="font-size: 10pt; color: rgb(153, 0, 204); font-family: Arial;">~lice // (above: Tapeworm)[] (above: lice) [] (left: tick) [] (left: flea) []
 * <span style="color: rgb(153, 0, 204); font-family: Arial;">3) PARASITISM- is a symbiotic relationship in which one organism (the parasite) lives in or on another organism (the host) and consequently harms it. (L.W.) **
 * Parasites receives all the nutrients of the host
 * Generally, parasites weaken their hosts but don’t kill them
 * The parasites can eventually kill their host if they stay on long enough, but it doesn’t usually happen
 * Parasites live off of their host’s blood, nutrients, skin, intestines, etc.

<span style="color: rgb(255, 0, 0);"> <span style="color: rgb(44, 39, 134);">

=<span style="color: rgb(0, 0, 255);"> = <span style="color: rgb(255, 0, 0);">
 * 4) DISEASE- any change, other than an injury, that disrupts the normal functions of the body. (all)**
 * Some diseases are produced by agents, such as bacteria, viruses, and fungi.
 * Others are caused by materials in the environment, such as cigarette smoke.
 * Still others, such as hemophilia are inherited.
 * Disease make those that have them very ill.
 * To uncover a disease, there are different symptoms to look for.


 * many diseases can cause death