Chapter 5 Interactions Environment and Organism

Environment Everything that effects an organism during its lifetime is collectively known as its ENVIRONMENT. Everything that effects an organism during its lifetime is collectively known as its ENVIRONMENT. Biotic Biotic Living Living Abiotic Abiotic Non-Living Non-Living

Limiting Factors A key factor, either biotic or abiotic, that restricts the success of the species. A key factor, either biotic or abiotic, that restricts the success of the species. Water Water Shelter Shelter Food Food Climate Climate Organisms Organisms Others Others

Range of Tolerance The extreme levels of a limiting factor within which an organism can still survive. The extreme levels of a limiting factor within which an organism can still survive. Dissolved Oxygen in Water Dissolved Oxygen in Water Temperature Temperature The larger the range the more successful is the organism The larger the range the more successful is the organism

Ecological Concepts Ecology Ecology The study of the way organisms interact with each other and their non-living surroundings The study of the way organisms interact with each other and their non-living surroundings

Habitat The space where an organism inhabits, the place where it lives. The space where an organism inhabits, the place where it lives. Climate Climate Soil condition Soil condition Water availability Water availability Other species in the area Other species in the area

Niche The fundamental role an organism has in its surroundings. The fundamental role an organism has in its surroundings. Everything affected by the organism Everything affected by the organism Everything that the organism affects Everything that the organism affects

Genes Genes Genes Distinct pieces of DNA that determine particular characteristics in an individual Distinct pieces of DNA that determine particular characteristics in an individual

Population Population Population All organisms of the same species in a geographic region All organisms of the same species in a geographic region

Species Species Species A population of organisms capable of reproducing among themselvesand having offspring that also can reproduce A population of organisms capable of reproducing among themselvesand having offspring that also can reproduce

Natural Selection The process that determines which individuals within a species will reproduce and pass their genes to the next generation. The process that determines which individuals within a species will reproduce and pass their genes to the next generation. Survival of the fittest Survival of the fittest

Forces of Natural Selection 1. Genotypic variation within a population 1. Genotypic variation within a population 2. Reproduction produces too many offspring. 2. Reproduction produces too many offspring. 3. Too many offspring lead to resource shortages. 3. Too many offspring lead to resource shortages. 4. Variation results in advantage during competition 4. Variation results in advantage during competition 5. Those individuals who are most successful survive to reproduce and pass their genes on to future generations. 5. Those individuals who are most successful survive to reproduce and pass their genes on to future generations.

Evolution The genetic and characteristic changes seen in species over long periods of time and many generations. The genetic and characteristic changes seen in species over long periods of time and many generations. Driven by natural selection Driven by natural selection

Speciation The production of new species from previously existing species. The production of new species from previously existing species. Usually occurs when a population is divided into two subpopulations and are isolated from one another Usually occurs when a population is divided into two subpopulations and are isolated from one another

Extinction The loss of an entire species. The loss of an entire species. Very common Very common 99.9% of all organisms have experienced extinction 99.9% of all organisms have experienced extinction

Coevolution The concept that two or more species of organisms can influence each other in a particular evolutionary direction. The concept that two or more species of organisms can influence each other in a particular evolutionary direction.

Mutation A random change in the genetic information in an individual. A random change in the genetic information in an individual.

Organism Interactions (5) Predation is a kind of interaction in which one animal kills/eats another. Predation is a kind of interaction in which one animal kills/eats another. Predator benefits from food. Predator benefits from food. Prey adaptation is manifested in a higher reproduction rate. Prey adaptation is manifested in a higher reproduction rate.

Competition Competition is an interaction in which two organisms strive to obtain the same limited resource. Competition is an interaction in which two organisms strive to obtain the same limited resource.

Types of Competition Intraspecific competition Intraspecific competition competition between members of same species. competition between members of same species. Interspecific competition Interspecific competition competition between members of different species. competition between members of different species.

Types of Competition The competitive exclusion principle holds that no two species can occupy the same ecological niche in the same place at the same time. The competitive exclusion principle holds that no two species can occupy the same ecological niche in the same place at the same time. Less-fit species must evolve into a slightly different niche. Less-fit species must evolve into a slightly different niche.

Symbiosis Symbiosis is a close, long-lasting, physical relationship between two different species. At least one species derives benefit from the interaction. Symbiosis is a close, long-lasting, physical relationship between two different species. At least one species derives benefit from the interaction.

There are three categories of symbiotic relationships: There are three categories of symbiotic relationships: Parasitism Parasitism Commensalism Commensalism Mutualism Mutualism

Parisitism Parasitism is a relationship in which one organism (parasite) lives in or on another organism (host), from which it derives nourishment. Parasitism is a relationship in which one organism (parasite) lives in or on another organism (host), from which it derives nourishment. Ectoparasites live on the host’s surface. Fleas, lice, molds, mildews Endoparasites live inside the body of the host. Tapeworms, malaria parasites, bacteria, fungi

Parisitism

Commensalism Commensalism is a relationship in which one organism benefits while the other is not affected. Commensalism is a relationship in which one organism benefits while the other is not affected. Remoras and sharks Remoras and sharks

Mutualism Mutualism is a relationship in which both species benefit. The relationship is obligatory in many cases, as neither can exist without the other. Mutualism is a relationship in which both species benefit. The relationship is obligatory in many cases, as neither can exist without the other. Yucca Moth Yucca Moth

Community A community is an assemblage of all interacting species of organisms in an area. A community is an assemblage of all interacting species of organisms in an area.

Ecosystem An ecosystem is a defined space in which interactions take place between a community, with all its complex interrelationships, and the physical environment. An ecosystem is a defined space in which interactions take place between a community, with all its complex interrelationships, and the physical environment.

Producers Producers: Organisms that are able to use sources of energy to make complex organic molecules from simple inorganic substances in their environment. Producers: Organisms that are able to use sources of energy to make complex organic molecules from simple inorganic substances in their environment.

Primary Consumers Primary consumers, or herbivores, eat plants as a source of food. Primary consumers, or herbivores, eat plants as a source of food.

Secondary Consumers Secondary consumers, or carnivores, are animals that eat other animals. Secondary consumers, or carnivores, are animals that eat other animals.

Omnivore Omnivores consume both plants and animals. Omnivores consume both plants and animals.

Decomposers Decomposers use nonliving organic matter as a source of energy and raw materials to build their bodies. Many small animals, bacteria, and fungi fill this niche. Decomposers use nonliving organic matter as a source of energy and raw materials to build their bodies. Many small animals, bacteria, and fungi fill this niche.

Keystone Species A keystone species plays a critical role in the maintenance of specific ecosystems. A keystone species plays a critical role in the maintenance of specific ecosystems. When bison are present in American tallgrass prairie ecosystems, they increase the biodiversity. When bison are present in American tallgrass prairie ecosystems, they increase the biodiversity. Bison wallows retain many species of plants that typically live in disturbed areas. Their feeding patterns affect the extent and impact of fire.

Keystone Species

Energy Flow through Ecosystems Each step in the flow of energy through an ecosystem is known as a trophic level. Each step in the flow of energy through an ecosystem is known as a trophic level. As energy moves from one trophic level to the next, most of the useful energy (90%) is lost as heat (second law of thermodynamics). As energy moves from one trophic level to the next, most of the useful energy (90%) is lost as heat (second law of thermodynamics). Because it is difficult to measure the amount of energy contained in each trophic level, biomass (weight of living material) is often used as a proxy. Because it is difficult to measure the amount of energy contained in each trophic level, biomass (weight of living material) is often used as a proxy.

Energy Flow through Ecosystems

Food Chains and Webs A food chain is a series of organisms occupying different trophic levels through which energy passes as a result of one organism consuming another. A food chain is a series of organisms occupying different trophic levels through which energy passes as a result of one organism consuming another. Some chains rely on detritus. Some chains rely on detritus. A food web is a series of multiple, overlapping food chains. A food web is a series of multiple, overlapping food chains. A single predator can have multiple prey species at the same time.

Food Chains and Food Webs Food chain Food web

Nutrient Cycles in Ecosystems— Biogeochemical Cycles Organisms are composed of molecules and atoms that are cycled between living and non-living portions of an ecosystem. Organisms are composed of molecules and atoms that are cycled between living and non-living portions of an ecosystem. These nutrient cycles are called biogeochemical cycles. These nutrient cycles are called biogeochemical cycles.

Carbon Cycle 1.Carbon and oxygen combine to form carbon dioxide. 2.Plants use carbon dioxide during photosynthesis to produce sugars. 3.Plants use sugars for plant growth. 4.Herbivores eat and digest plants. 5.Respiration breaks down organic molecules into CO 2 and water and releases those compounds back into the atmosphere. 6.The decay process of decomposers involves respiration and therefore recycles naturally occurring organic molecules. 7.Burning fossil fuels takes carbon atoms that were removed temporarily from the active, short-term carbon cycle and reintroduces them into the active cycle.

Carbon Cycle

Nitrogen Cycle The nitrogen cycle involves the cycling of nitrogen atoms between abiotic and biotic ecosystem components. The nitrogen cycle involves the cycling of nitrogen atoms between abiotic and biotic ecosystem components. Producers are unable to use atmospheric N. Producers are unable to use atmospheric N. Nitrogen-fixing bacteria convert nitrogen gas N 2 into ammonia. Nitrogen-fixing bacteria convert nitrogen gas N 2 into ammonia. Plants construct organic molecules. Plants construct organic molecules. Decomposers also break down nitrogen-containing molecules, releasing ammonia. Decomposers also break down nitrogen-containing molecules, releasing ammonia.

Nitrogen Cycle

Phosphorus Cycle The ultimate source of phosphorus atoms is rock. The ultimate source of phosphorus atoms is rock. 1. Phosphorus compounds are released by erosion and become dissolved in water. 2. Plants use phosphorus to construct necessary molecules. 3. Animals gain necessary phosphorus when they consume plants or other animals. 4. Decomposers recycle phosphorus compounds back into the soil.

Phosphorus Cycle