Living Things and the Environment
Chapter 21, Section 1
Key Concepts:
 What needs are met by an
organism’s environment?
 What are the two parts of an
organism’s habitat with which
it interacts?
 What are the levels of
organization within an
ecosystem?
Key Terms:
 Organism
 Habitat
 Biotic factor
 Abiotic factor
 Photosynthesis
 Species
 Population
 Community
 Ecosystem
 Ecology
Living things:
 People
 Plants
 Animals
Nonliving things:
 Sunlight
 Soil
 Air
How do living things
depend on the nonliving
things?
Organisms in their Habitats
Image Source Page: http://www.wildherps.com/species/C.atrox.html
Image Source Page: http://www.orww.org/brandis_oaks/animals/
Image Source Page: http://www.reefnews.com/reefnews/photos/corals/habitat.html
http://www.knowledgerush.com/kr/encyclopedia/Prairie_dogs/
Image Source Page: http://www.pictures-of-cats.org/cheetah-habitat.html
An organism obtains food, water, shelter, and other
things it needs to live, grow, and reproduce from it’s
environment. The environment is called it’s habitat.
 The living parts of a habitat are
called biotic factors.
Biotic factors of a prairie dog:
 Grass and plants provide seeds and
berries
 Hawks, ferrets, badgers and eagles
that hunt the prairie dogs are biotic
factors
 Worms, fungi, and bacteria are
biotic factors that live in the soil
underneath.
http://www.knowledgerush.com/kr/encyclopedia/Prairie_dogs/
Abiotic factors are the nonliving parts of an organism’s habitat:
Water
 All living things require it to carry out their life processes.
 Makes up a large part of an organism
 Human body is 65% water
 Plant and algae need water, sunlight, and carbon dioxide to make
their food in a process called photosynthesis.
Sunlight
 Needed for photosynthesis, without it plants and algae can’t grow
Oxygen
 Also require by living things to carry out their life processes.
 Humans can only live a few minutes without it.
 Fish and other water organisms obtain oxygen that is dissolved
in the water around them.
Temperature
 Determine the types of organisms that can live there.
 Some organisms alter their environment to survive extreme
temperatures
 Prairie dog dig underground.
Soil
 Soil is a mixture of rock fragment, nutrients, air , water and the
decaying remains of living things.
 The type of soil influences the kinds of plants that can grow there.
 Some organisms use the soil as home.
 Billions of microscopic organisms such as bacteria also live in
the soil

http://www.rockymountainreflections.com/horses4.html
How are species and population related?
http://www.abouttanzania.com/places.html
Review
 What basic needs are provided by an organism’s habitat?
 Food, water, shelter, and other things an organism needs to
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survive.
What the difference between a biotic factor and a abiotic factor?
Biotic
All living organisms
Abiotic are nonliving and needed for organisms to survive
Examples: Soil, air, sunlight, temperature
Population, organism, ecosystem, community – list in order from
the smallest to the largest in an ecological system
Organism, population, community, ecosystem