Environmental Science
Name: ______________________________
Chapter 2: The Organization of Life
Goal: The student will distinguish between the biotic and abiotic factors in an ecosystem, describe how a
population differs from a species and explain how habitats are important for organisms.
Vocabulary:
1. Ecosystem2.
Biotic factor-
3. Abiotic factor4. Organism5. Species6. Population7. Community8. Habitat-
Chapter 2.1: Ecosystems: Everything is Connected
 Scientists don’t yet completely understand how the environment works because it is so complex and
interconnected
 Human actions have unexpected effects on the environment (ex: Borneo in Southeast Asia; pesticide
DDT)
 The unfortunate chain of events on Borneo occured because the living things were connected to each
other
Defining an Ecosystem?
 An ecosystem includes all the different organisms living in a certain area, along with their physical
evironment (ex: coral reef, wetlands)
Ecosystems Are Connected
 Ecologists think of an ecosystem as an isolated unit, but ecosystems usually do not have clear, cut
boundaries; things move from one ecosystem to another (ex: birds fly from one ecosystem in summer to
another in winter)
The Components of an Ecosystem
 Ecosystems contain both biotic factors (living parts: animals, plants, dead organisms, dead parts of
organisms, such as leaves, and organisms’ waste products) and abiotic factors (nonliving parts:
temperature, sunlight, soil type, air,water, rocks, sand)
 All parts work together in an ecosystem, if one part is destroyed, the entire ecosystem can be affected
Organisms
 An organism is one individual living thing (ex: an ant, an ivy plant, a gorilla)
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A species is a group of organisms that are able to produce fertile offspring and share common genes,
therefore, resemble each other (ex: all humans, domestic dogs)
Members of a species may not all live in the same place (field mice in Maine and field mice in Florida
are the same species but may never interact with one another)
Every organism is a member of a species (humans – homo sapiens)
Populations
 A population is a group of individuals of the same species living in a particular place (ex: the bullfrog
population of a pond, the lion population of a savanna)
 Ex: all the field mice in a corn field make up on population of field mice
 Important characteristic of populations: Members of that population will breed with one another rather
than with other populations.
Communities
 Organisms don’t exist in isolation, neither does a population, every population is a part of a community
 Communities are all the living inhabitants of interacting populations of different species living in an
ecosystem (ex: a pond community includes the different plants, fish, insects, amphibians,
microorganisms the live in and around the pond)
 The obvious difference between communities is the types of species they have. Land communities will
have a few species of plants. Depending on what those plants are will determine what other organisms
live in that community.
Habitat
 All organisms live in particular places. That place is called its habitat. Ex: A howler monkeys habitat is
the rain forest, a cactus’s habitat is a desert, a waterlily’s habitat is a pond.
 Every habitat has specific characteristics that the organism needs to survive and those organisms are
well suited to their natural habitats. If those factors change, then the habitat changes.
Lesson Reflection:
Complete the Organizational Pyramid handout. Use your notes to complete each section. Label each
level, draw a picture and outside the pyramid, write the definition and give an example.
Assessment:
1. List the abiotic and biotic components you see in the picture provided.
2. Describe a population not mentioned in this section.
3. Explain the difference between a population and a species.
Lesson Extension (Technology/Application/Connection to Real World):