CP Biology
2015-2016
Name
UNIT 2A: Part I - Introduction to Ecology
Science is a body of knowledge and skills acquired through
systematic experimentation and observation to describe natural
phenomena; or, more simply, it is a “way of knowing”. The process
of science helps biologists investigate how nature works at all
levels, from the molecules in cells to the biosphere.
3.1 What is Ecology?
Biosphere: all life on Earth and all parts of Earth in which
life exists including land, water and air or atmosphere.
Ecology: the scientific study of interactions among
organisms and between organisms and their physical
environment.
The existence of life on Earth depends on interactions among organisms
and between organisms and their environment. There is a great diversity
among living organisms yet there are similar characteristics that all
organisms share.
Where is the biosphere located AND what does it include?___________
__________________________________________________________
__________________________________________________________
How is economics linked with ecology? __________________________
____________________________________________________________
__________________________________________________________
Levels of Organization in the biosphere: (use #2-7 from USG to label)
Interactions within the biosphere produce a web of
interdependence between organisms and the environments
in which they live.
Organisms respond to their
environments and can also change their environments;
therefore, biosphere is dynamic and ever-changing.
How is economics linked with ecology?
Your personal notes, summary of the lesson, and/or questions that you may have:
1
*Practice Task:In the space below, fill in the blanks with the
appropriate levels of organization using the word bank below.
Word Bank
Biome
Community
Population
Biosphere
Ecosystem
Organism
Your personal notes, summary of the lesson, and/or questions that you may have:
2
Environment: all conditions or factors surrounding an
organism
**Environmental conditions include both biotic and abiotic
factors**
Biotic Factors
________________________________________________
________________________________________________
Pick any organism and name 4 biotic factors relating to it:
Organism: __________________
1. ___________________________________
2. ___________________________________
3. ___________________________________
4. ___________________________________
Abiotic Factors
________________________________________________
________________________________________________
Using the same organism you picked earlier, name 4 abiotic factors
relating to it
1. ___________________________________
2. ___________________________________
3. ___________________________________
4. ___________________________________
Abiotic and Biotic factors are closely linked. Many physical
(abiotic) factors can be strongly influenced by the activities
of organisms. The dynamic mix of biotic and abiotic factors
shapes every environment.
Is a mucky shoreline around a pond strictly part of the physical
(abiotic) environment? Explain.
___________________________________________________________
___________________________________________________________
___________________________________________________________
Your personal notes, summary of the lesson, and/or questions that you may have:
3
3.2 Energy, Producers, and Consumers
What would happen to the amount of oxygen in our
atmosphere without the presence of photosynthetic
Energy is needed to power life's processes (including growth,
producers?
reproduction, metabolism, etc.). No organism can "create"
___________________________________________________
energy. Organisms can only use energy from other sources.
You may have wondered where this energy comes from and how ___________________________________________________
___________________________________________________
it is transferred from one organism to another.
For most life on Earth, sunlight is the ultimate energy source.
However, for some organisms, chemical energy stored in
inorganic chemical compounds serves as the ultimate energy
source for life processes.
Name three examples of organisms which are
autotrophs (primary producers):
1. _____________________________
2. _____________________________
The following are the only organisms that can capture energy
from sunlight or chemicals and convert it into forms that living
cells can use, therefore they are essential to the flow of energy
through the biosphere. They store energy in forms that make it
available to other organisms that eat them.
3. _____________________________
Autotrophs: organism that is capable of capturing energy from
sunlight or chemicals and use to produce its own food from
inorganic compounds;
Photosynthesis
Also Known As: Producers
The next process is how the best-known and most common
primary producers harness solar energy
Photosynthesis: captures light energy and uses it to power
chemical reactions that convert carbon dioxide and water into
oxygen and energy-rich carbohydrates such as sugars and
starches
Chemosynthesis: Chemosynthetic autotrophs do not need
sunlight. Often they may be found in extreme environments
such as tidal marshes along the coast, or around hot springs or
volcanic vents on the ocean floor. Here they utilize the energy
stored in chemical bonds of inorganic molecules such as
hydrogen sulfide to make energy-rich carbohydrates.
Your personal notes, summary of the lesson, and/or questions that you may have:
4
Consumers are organisms that cannot directly harness energy
from the environment as autotrophs do.
Heterotrophs: organism that obtains its energy by consuming
other organisms
Name three examples of organisms which are heterotrophs
(consumers).
1. _____________________________
2. _____________________________
Also Known As: Consumers
3. _____________________________
Consumers are classified by the specific ways in which they acquire energy and nutrients from other organisms.
The type of "food" eaten may vary widely from one type of consumer to another.
Realize, however, that organisms in nature often do not stay inside the tidy categories in which ecologists place them.
For example, some animals often described as carnivores will scavenge if they get a chance.
Examples of:
Herbivores: organisms that obtain energy by eating plant
Herbivores: ________________________________________
leaves, roots, seeds, and or fruits
___________________________________________________
Carnivores: organisms that obtain energy by eating animals
Carnivores: ________________________________________
___________________________________________________
Omnivores: organisms that obtain energy by eating both plants
Omnivores: ________________________________________
and animals
___________________________________________________
Decomposers: organisms that break down and obtain energy
Decomposers: ______________________________________
from dead organic matter
___________________________________________________
Detritivores: organisms that feed on detritus which are the
Detritivores: _______________________________________
small pieces of dead and decaying plant and animal remains
___________________________________________________
Scavengers: animals that consume the carcasses of other
Scavengers: ________________________________________
animals
___________________________________________________
Your personal notes, summary of the lesson, and/or questions that you may have:
5
3.3 Food Chains and Food Webs
Example of a Food Chain
Energy flows through an ecosystem in a one-way stream,
from primary producers to various consumers.
You can think of energy as passing through an ecosystem
along a food chain. Some food chains are simple, being
composed of only two steps, while others can be longer
with as many as 5 or 6 steps!
Food chain: a series of steps in an ecosystem in which
organisms transfer energy by eating and being eaten
Construct a 4-step food chain below:
grass
 ______________  ______________  ______________
A common type of primary producer found at the base of
many aquatic food chains is a mixture of floating algae
called phytoplankton and attached algae.
Partially because many animals eat more than one kind of
food, a single, simple food chain is usually insufficient to
describe the complicated feeding relationships typically
found in an ecosystem.
Food Web: network of complex interactions formed by the
feeding relationships among the various organisms in an
ecosystem; a food web can also be defined as a series of
interconnected food chains in an ecosystem.
Therefore studying a food web may be more appropriate
when trying to understand the flow of energy and materials
in a complex ecosystem
What do you think would happen to the ecosystem above if the
algae were killed off?__________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
Your personal notes, summary of the lesson, and/or questions that you may have:
6
All of the animals in the food web shown to the right,
ultimately depend on krill. If the marine algae
population is disturbed, then there may be changes in
all of the populations connected in this food web.
Killer whales indirectly depend on krill for
survival.
The food web shows that killer whales depend directly
on blue whales and leopard seals to obtain energy.
Blue whales consume krill for energy; therefore, since
killer whales consume blue whales, killer whales
indirectly depend on the krill population for energy.
Leopard seals consume Adelie penguins which in turn
consume krill, so again, killer whales depend on krill
for energy, indirectly. In addition, krill are the only
herbivores in this web, so they are the only organisms
that consume the primary producers of this web.
Food chains and food webs cannot go on forever; in other words they
cannot have an unlimited number of trophic levels. Why do you think
this is true? _______________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
Some might make an analogy of decomposers being like earth's
"recycling center". Summarize the importance of decomposers and
detritivores in food webs.
Primary producers are always at the first trophic level
of a food chain or food web.
Trophic level: each step in a food chain or a food web
Your personal notes, summary of the lesson, and/or questions that you may have:
7
4.2 Niches and Community Interactions
When trying to understand fully why an organism lives where it does and how it fits into its surroundings, an ecologist needs to
know more than just where an organism can be found.
The Niche
Each species has a range of conditions under which it can grow and reproduce; this is part of the reason why organisms occupy
different places and help to define where and how an organism lives.
Each species has its own range of tolerance.
Tolerance: the ability to survive and reproduce under a range of environmental circumstances
A species' tolerance for environmental conditions
helps determine its habitat (address").
Outside of optimum ranges, the organism experiences stress because it has to
expend more energy to maintain homeostasis, leaving less available energy
for growth and reproduction. Every organism has an upper and lower limit of
tolerance for every environmental factor. Beyond those limits, the organism
cannot survive.
Habitat: area where an organism lives including the biotic and abiotic
factors that affect it
In addition to an "address", a species also has an ecological "occupation" - where and how it "makes a living".
Niche: the range of physical and biological conditions in which a species lives and the way the species obtains what it needs to
survive and reproduce.
Your personal notes, summary of the lesson, and/or questions that you may have:
8
Competition
Competition: occurs when organisms attempt to use the same limited ecological resource in the same place at the same time.
Intraspecific competition: competition among members of the same species.
Interspecific competition: competition between members of different species.
If we look at natural communities, we rarely find species whose niches overlap significantly. Direct competition between different
species almost always results in a "losing" species which dies out.
4.4 Biomes
Biomes are described in terms of abiotic factors
like climate and soil type, and biotic factors like
plant and animal life.
Even within a well-defined biome, there is often
considerable variation among communities of
plants and animals - these variations can be
caused by differences in local conditions and can
be greatly influenced by human activity or
community interactions.
In which biome is Livingston, New Jersey
located?
_______________________________________
Your personal notes, summary of the lesson, and/or questions that you may have:
9