Chapter 24-1/25-1:
Biosphere : the part of Earth that supports life
1. The top portion of Earth’s crust, all the waters on Earth’s surface, and the surrounding atmosphere
2. Made up of different environments that are home to different kinds of organisms
Ecosystem : all the organisms living in an area and the nonliving parts of their environment
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Ecology is the study of interactions that occur among organisms and their environment.
Ecosystems is made up of:
I. Living Environment (biotic) Factors:
Biotic:
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Living things rely on non-living things to live. Ex. The grass relies on sunlight (abiotic)
Living things also rely on living things for food. Ex. The lion (biotic) relies on antelope
(biotic). a. Animals:
1. A species is an organism that contains similar traits that can reproduce and have fertile offspring.
2. A population is made up of all the organisms in an ecosystem that belong to the same species.
3. A community is all the populations in an ecosystem. b. Plants
1. tree’s in a given area that are supported by the climate
II. Non-Living Environment =Abiotic Factor a.
Rocks (contain minerals) b.
Water (lakes, rivers, ponds, rain, snow) c.
Wind d.
Sun
Abiotic:
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Aids in the balance of an ecosystem
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Living things can not live without water, sunlight, minerals, air (CO2 and O2)
Climate: temperature, Precipitation(rainfall).
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Of all abiotic factors, sunlight drives all life processes

Climate: an area’s average weather conditions over time, including temperature, precipitation, and wind
1. For most living things, temperature and precipitation are the two most important components of climate.
2. Heat energy from the Sun creates air currents called wind.
Levels of Biological Organization:
1.
Organism: single individual of a population
2.
Population:
3.
Communities
4.
Ecosystem
5.
Biosphere smallest largest
Post Section Questions:
1. What is the difference between a population and a community?
2. What is the difference between abiotic factors and biotic factors?
3. What is the relationship between abiotic, communities and ecosystems?
A. Sun—source of energy that fuels most life on Earth
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Matter can be recycled over and over again, but energy is converted from one form to another.
1. Producers —organisms that use an outside energy source to make energy-rich molecules a. Most producers use the Sun and contain chlorophyll, a chemical required for photosynthesis. b. Some producers, found near volcanic vents on the ocean floor, use inorganic molecules as energy sources for chemosynthesis.
2. Consumers —organisms that cannot make their own energy-rich molecules; they obtain energy by eating other organisms. a. Herbivores, such as deer and rabbits, eat plants. b. Carnivores, such as frogs and lions, eat animals. c. Omnivores, such as pigs and humans, eat both plants and animals d. Decomposers, such as earthworms and bacteria, eat dead organisms
B. Energy stored in the molecules of one organism is transferred to another when one organism becomes food for another organism.

3 Types of Symbiosis:
Symbiosis : any close relationship between species
1. Mutualism : a symbiotic relationship in which both species benefit
2. Commensalism : a symbiotic relationship in which one organism benefits and the other is not affected
3. Parasitism —a symbiotic relationship in which one organism benefits and the other is harmed
Niche —an organism’s role in its environment, including its habitat and food, and how it avoids danger, finds a mate and cares for its young
2 Niche Types:
1. Predator and prey: a. Predator—consumer that captures and eats other consumers b. Prey—the organism that is captured by the predator c. Predators limit the size of prey populations, increasing the number of different species that can live in an ecosystem
2. Cooperative actions improve a species’ survival : a. Example: one deer warns the others of predators in the area. b. Example: individual ants perform different tasks required for the survival of all.
3. Food chains: a simple way of showing how matter and energy pass from one organism to another ecosystem
Example:
4. Food web: shows all the possible feeding relationships among the organisms in a community

Example.
5. Energy pyramid— shows the amount of energy available at each feeding level in an ecosystem
A. Earth’s biosphere contains a fixed amount of water, carbon, nitrogen, oxygen, and other materials that cycle through the environment and are reused by different organisms.
B. Water cycle: how water moves from the Earth’s surface to the atmosphere and back to the surface again
Water Cycle:

1. Evaporation: when liquid water changes into water vapor and enters the atmosphere
2. Condensation: the process of changing water from a gas to a liquid
3. When water drops become large and heavy enough, they fall to the ground as rain or other precipitation.
C. Nitrogen cycle: the transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to the atmosphere
1. Nitrogen fixation: a process in which some types of soil bacteria can form the nitrogen compounds that plants need
2. Farmers replace nitrogen in the soil by growing nitrogen-fixing crops or using fertilizers that contain nitrogen compounds that plants need for growth.
Nitrogen Cycle
Denitrifying bacteria
D. Oxygen/Carbon cycle: how carbon molecules move between the living and nonliving world
Oxygen/Carbon Cycle

1. Producers remove carbon dioxide gas from the air during photosynthesis.
2. Respiration: the chemical process that provides energy for cells