Section 1: Organisms and Their Environment
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Biology Chapter 2: Principles of Ecology Section 1: Organisms and Their Environment
Studying Nature People show interest in their natural surroundings ______– study of plants and animals, including where they grow and live, and what they eat, or what eats them
What is ecology? The branch of biology that developed from ______. Ecology – the study of interactions that take place between ______and their ______.
The Biosphere Living things are found in the______, on ______, and in both fresh and salt ______. The biosphere is the portion of Earth that supports living ______. ( high in ______to bottom of______) Very ______portion of Earth. Living things are affected by both the ______and ______environment and by other ______things.
Abiotic Factors ______part of an organisms environment. Examples: ______currents, ______, ______, ______, and______. Ecology includes the study of features of the environment that are not living because these features are part of an organism’s life. Abiotic features have obvious effects on living things and often determine which species ______in a particular environment.
Biotic Factors All the ______organisms that inhabit an environment. All organisms depend on others directly or indirectly for ______, ______, ______, or ______.
Levels of Organization Ecologists study individual ______, interactions among organisms of the same______, and interactions among organisms of______, as well as the effects of ______factors on interacting species. To help them understand the interactions of the biotic and abiotic parts of the world, ecologists have organized the living world into levels The ______by itself, ______, ______, and ______.
Interactions within populations A population is a group of organisms, all of the______, which ______and live in the same ______at the same ______. Sharing of a resource can show how far apart the organisms ______and how large the populations become. The same population can compete for ______or other ______
Interactions within Communities No species lives ______. ______– is made up of interacting populations in a certain area at a certain time. A change in one population in a community may cause ______in the other populations. More hawks = ______mice
Biotic and Abiotic Factors form Ecosystems An ecosystem is made up of interacting ______and a biological community’s ______factors. Because animals and plants in an area can change, and because abiotic factors can change, ______are subject to change.
Two Main Types of Ecosystems ______ecosystems Those that are located on ______. Examples: forests, meadows, and rotting logs ______Ecosystems Occur in both ______and ______forms. Make up approximately ______% of the Earth’s surface.
Habitat The place where an organism lives out its ______. Examples: prairie dog = burrows birds = specific trees A lawn, the bottom of a stream, pond, or specific area of the ocean Habitats can change due to ______and ______causes. They can even ______
Niche Although several species may share a habitat, the food, shelter, and other essential resources of the habitat are often used in different ways. When looking closely each population ______in different ways, on different ______, and at different ______. These differences lead to reduced ______. Each species occupies a ______ A niche is all ______and ______a species uses in its environment- how it meets its specific needs for food and shelter, how and where it survives, and where it reproduces Survival Relationships A predator is a type of ______. They seek out and ______other organisms. Predators eat prey ( organisms they feed on ) Predator – prey relationships involve a fight for ______but not all organisms are in a continuous battle for survival.
Symbiosis The relationship in which there is a close and permanent ______between organisms of different______. Three types ______ ______ ______
Mutualism Both species ______from the relationship Acacia tree and ants
Commensalism One species ______and the other species is neither ______nor ______. Occurs in plants and animals Spanish moss
Parasitism ______to one species while ______to another. Dogs or cats with ticks
Chapter 2 Section 2 Nutrition and Energy Flow
How Organisms Obtain Energy In important characteristic of a species niche is how it obtains ______. Ecologists trace the flow of energy through ______to discover ______relationships between organisms.
The Producers: Autotrophs Ultimate source of energy is ______ Plants use the sun’s energy to make food in a process called ______. ______– organism that uses ______energy or energy stored in chemical compounds is a ______.
The Consumers: Heterotrophs Depend on ______for nutrients and energy. An organism that ______make its own food and feeds on other ______. Can feed only on______, only on other ______, and both ______and ______.
Herbivore Feeds only on ______ Rabbits, grasshoppers, beavers, squirrels, bees, elephants, fruit-eating bats, and some humans.
Carnivores Some heterotrophs eat other ______. Animals eat such as lions that kill and eat only other animals are ______.
Scavengers Do not ______for food. Eat animals that have already______. Play a beneficial role in the environment.
Omnivore Eat both ______and ______ humans
Decomposers ______and release nutrients from ______organisms. Bacteria and fungi
Flow of Matter and Energy in Ecosystems Matter in the form of carbon, nitrogen, and other elements, flows through the levels of an ecosystem from producers to consumers. Matter is ______ As you cycle matter, some trapped energy is ______from one level to the next. At each level, a certain amount of energy is also transferred to the environment as ______.
Food Chain ______model of energy flow In a food chain, nutrients and energy move from ______to ______and, eventually, to ______. Drawn with ______to indicate the direction in which energy is transferred. Consist of two, three, or four transfers The amount of energy remaining at the end is only a portion of what was available at the first transfer. Only shows ______possible route for the transfer of matter and energy.
Trophic Levels Represent Links in the Chain Each organism in a food chain represents a feeding step, of______, in the passage of energy and materials. A ______species may exist at different ______because they eat a variety of foods.
Food Webs Shows ______feeding relationships at each trophic level in a community. More realistic model than a ______because most organisms depend on more than ______other species for food.
Energy and Trophic levels: Ecological Pyramid ______pyramid can show how energy flows through an ecosystem.
Pyramid of Energy Illustrates that the amount of energy ______at each succeeding ______. Total energy transfer from one trophic level to the next is only about ______percent because organisms fail to capture and eat all the food energy available at the trophic level below them. When an organism consumes food, it uses some of the energy in the food for it ______. ______is neither lost nor gained
Pyramid of Numbers Shows that population sizes ______at each higher trophic level. Not always true, one tree can be food for thousand of insects, therefore the pyramid would be ______.
Pyramid of Biomass Biomass is the total ______of living matter at each trophic level. A pyramid of biomass represents the total ______of living material available at each trophic level.
Cycles in Nature The atoms of carbon, nitrogen, and other elements that make up the bodies of organisms alive today are the ______atoms that have been on Earth since life began.
Water Cycle Life depends on ______.
The Carbon Cycle All life based on ______molecules.
The Nitrogen Cycle Nitrogen in converted from a ______to compounds important for life and back to a gas.
The Phosphorus Cycle All organisms require phosphorus for ______and ______. Cycles two ways: ______term and ______ Short term: Plants obtain phosphorus from the soil. Animals obtain phosphorus by eating plants. When they die phosphorus is returned to soil. Long term: Phosphate washed into water become incorporated into rock as insoluble compounds. Millions of years, as the environment changes, the rock containing phosphorus is exposed. As the rock erodes, the phosphorus again becomes part of the local ecological system.
Phosphorus Cycle