Download File - Biology with​Mrs. Ellsworth

Name _____________________________________ Date ________________ Period ___________
Ecology Review Worksheet #2
Key Concept: Every organism has a habitat and niche.
1. What is the difference between an organism’s habitat and its niche?
Habitat: (Home) Organism's habitat (where a species live) can be described as all of the
biotic and abiotic factors in the area where an organism lives.
Niche: (Home & Occupation) Ecological niche (how species live) is composed of all of
the physical, chemical, and biological factors that a species needs to survive, stay
healthy, and reproduce. Niche includes food, abiotic conditions, and behavior.
2. For each type of symbiotic relationship, complete the chart with details about how each organism is
impacted using the terms “Benefits,” “Harmed,” or “No impact.” For each situation, assume that
Organism A initiates the relationship.
Symbiotic Relationship
Mutualism
Organism A
Organism B
Benefits
Benefits
Commensalism
Benefits
No impact
Parasitism
Benefits
Harmed
3. How is parasitism similar to and different from predation?

Both involve pairs of species in which one species increases its population at the expense
of decreasing the population of the other species
 Predators are generally bigger than their prey and kill the prey instantly
 Parasites are smaller than their prey and normally kill the prey slowly, if at all
MAIN IDEA: Changes in a population’s size are determined by immigration, births, emigration,
and deaths.
Choose a word from the box below that best completes each sentence.
births
increases
emigration
deaths
immigration
abundant
4. When resources are abundant in a particular area, individuals may move into the population of this
area. This movement of individuals into a population from a different population is called
immigration.
5. A very cold winter has left many deer in a population hungry and sick. By the end of the winter,
this population will likely decrease because of deaths.
6. A deer population experiences growth when the rate of reproduction increases This change in
population size is due to births.
7. As humans move into their territory, many members of a deer population move away and join other
herds. This movement of individuals out of a population into a new population is called emigration.
8. How does the availability of resources affect population growth?
________If resources are abundant then population will grow. If resources are scarece and
limited then the population will level off or decrease_____________________________________
The population of a predator can be limited by the available prey, and the population of prey can be limited
by being caught for food. Use the information in the graph below to answer the questions that follow.
9) Describe the pattern seen in the graph above.
The lines appear to switch sides and be opposite of each other.
10) How does the wolf population affect the carrying capacity of the moose population?
As the population of the prey increases then the predator population increases.
As the number of predators increase then the number of prey decrease.
Each time an ecosystem is damaged, the process of succession re-forms the area. Succession is the
sequence of biotic changes that regenerate a damaged community or create a community in a
previously uninhabited area. Succession is a process with no distinct beginning or end. In a
community, succession is always occurring.
After a volcano erupts, the molten lava hardens and leaves behind nothing but solid rock. Primary
succession is a type of succession that begins with a previously uninhabited, barren landscape. Pioneer
species are the first organisms that live in this type of habitat. Pioneer species begin the process of
breaking down the rock into soil that can hold plants. This process may take hundreds of years, but
eventually the soil produced by pioneer species will give rise to entire ecosystems of plants, animals,
and other organisms.
More often an environment had many different plants and animals, but a disaster such as a fire or flood
may have destroyed much of the habitat. Secondary succession is the reestablishment of a damaged
ecosystem in an area where the soil was left intact. The dynamic processes of succession are always
changing the face of an ecosystem.
11) Why are pioneer species so important for primary succession?
______The pioneer species help build up soil as they break down the rocks into soil and as they
die and contribute their own organic matter to become soil.______________
12) Explain why succession is a never-ending process.
Change is always happening. Things eventually die and new things grow. Weather, fires, diseases,
volcanoes, humans and many other things cause constant change. So, succession is never-ending.