Download Science Chapter 7 Notes

Science Chapter 7 Notes:
Lesson 1: Why do adaptations vary
among species?
Adaptation- A characteristic that
enables an organism to survive and
reproduce in its environment.
Camouflage-The ability to blend in with
the environment and/or surroundings
Mimicry- the resemblance of an animal
species to another species
A. Examples of adaptations:
Animal
chameleon
Adaptation
camouflage
Viceroy
butterfly
Elephants
Mimics the
colors and
markings of a
monarch
butterfly, but
is not
poisonous
Moves in
large groups
Structural Adaptations: the body parts
or physical features of species that help
them to survive.
Examples:
1. Bills on birds that help them eat,
2. Web feet to help them swim,
3. Waterproof skin to keep too much
water from coming into the body
Behavioral Adaptations: The things
organisms DO to help them survive.
Examples:
1. Migration-to pass periodically
from one region or climate to
another, as certain birds, fishes, and
animals in wintertime
2. Hibernation-to spend the winter in
close quarters in a dormant condition,
as bears and certain other animals.
3. Nocturnal- active at night
4. Diurnal- active during the day
Lesson 2, Chapter 7 Notes
I. Predators- A predator is an animal
that catches and devours its prey. The
animal that is eaten is the prey. Predators
are classified as carnivore, herbivore
and omnivore.
A. Carnivore- are animals that eat
only other animals. (Wolf)
B. Herbivore -are animals that eat
only plants. (Grasshopper)
C. Omnivore-are animals that eat
both plants and animals. (Opossum)
II. Predator-prey relationship
A. Producer- is a green plant able to
make its own food by photosynthesis.
B. Consumers- an organism that
depends on producers for its food
needs.
TROPHIC LEVELS FOR
CONSUMERS
1. Primary- Primary consumers
pretty much eat only plants
(exception is an omnivore)
Animals like rabbits, horses and
cows are exclusively primary
consumers
2. Secondary-eat primary
consumers (A lion that kills and
eats a zebra is a secondary
consumer
3. Tertiary- Tertiary consumers
eat secondary consumers. If a bear
eats a fish, which has been
feeding on algae, the bear is
functioning as a tertiary
consumer. The fish was a primary
consumer; the algae were
producers
4. Quaternary-Quaternary
consumers eat tertiary consumers.
In the above example how could
the bear be a quaternary
consumer?
C. Decomposer-an organism that
obtains its food from wastes and dead
organisms.
III. Energy transfer in Ecosystems
A. Food Chain- Shows a possible
path that energy can take through
an ecosystem.
1. A food chain is the sequence of
who eats whom in a biological
community (an ecosystem) to
obtain nutrition.
Example:
B. Food Web-Shows how food
chains in an ecosystem are
connected
Example:
Grass-rabbitfox
Grassgrasshopperrateagle
C. Energy Pyramid:
1. In any food web, energy is lost
each time one organism eats
another. Because of this, there have
to be many more plants than there
are plant-eaters. There are more
autotrophs than heterotrophs, and
more plant-eaters than meat-eaters.
2. As energy goes “up” the pyramid,
energy decreases
a. Energy lost as the animal uses it
b. Energy lost as heat
c. Energy is stored in the organisms’
tissues
c. Only about 10% of an organisms
energy is passed
from one level
of a food chain to the next.
3. As organisms go “down” the
pyramid, their numbers increase
4. Harmful substances can also pass
from organism to organism (chemicals,
viruses, bacteria, gases, etc)
Lesson 3, Chapter 7 Notes:
Competition
I. Competition- the struggle among
organisms to survive in a habitat with
limited resources.
A. Organisms that can adapt have
a better survival rate
B. Competition occurs when
organisms have similar needs
C. Predator/ Prey Relationships
1. Predators feed on prey
(predation)
2. Increases and decreases in
the number of predators affect
the number of prey
3. Carrying Capacity-How
many organisms an
ecosystem can support
II. Symbiosis- a close, long term
relationship between organisms that
benefits at least one of the organisms.
A. Types of symbiosis
1. Parasitism- one organism is
helped, but the other is harmed
a. parasite- the organism that
benefits from the
relationship
b. host- the organism that is
harmed
c. Example-Ticks that suck
the blood of deer.
2. Mutualism- both organisms
benefit
a. Example: Clownfish and sea
anemone.
(1) The tentacles around the
mouth of the sea anemone will
be used to eat many fish, but
not the clownfish.
(2) The clownfish swim out
and capture food, then return
to the tentacles (which protect
them from predators) and the
sea anemone will eat food
scraps that fall from the mouth
of the fish.
3. Commensalism- helps one
organism but neither helps nor
harms the other organism
a) Example:
1. Birds use tree
branches for roosting
sites.
2. The trees get nothing
but are not harmed.
Lesson 4 Lecture Notes- “How
Materials cycle Through an Ecosystem”
Cycles of Matter
Background Information:
Matter: anything that has mass and
takes up space.
Forms of matter: solid, liquid, and gas.
Matter can change physically and
chemically.
Law of Conservation of Matter: Matter
can neither be created or destroyed in
chemical or physical processes.
1. Water Cycle: the process of
evaporation, condensation and
precipitation.
a. Evaporation: liquid to gas
b. Condensation: gas to liquid
c. Precipitation: Water vapor in clouds
condenses to form rain, snow, sleet or
hail.
2. Carbon Cycle: Producers, consumers,
and decomposers play roles in the
recycling of carbon and oxygen in an
ecosystem.
a. During photosynthesis producers
convert carbon dioxide gas into fodd
molecules.
b. Consumers eat producers breaking
down these carbon compounds to get
energy.
They release carbon dioxide as a waste
product of this process.
c. Decomposers also release carbon
dioxide when they breakdown wastes in
the environment.
3. Oxygen Cycle:
a. Producers release oxygen as a byproduct of photosynthesis.
b. Most organisms need oxygen to
carry out their own life processes.
4. Human Impact:
a. Burning fossil fuels uses oxygen
and releases more carbon dioxide.
b. Cutting down trees reduces the
number of producers that can create
oxygen.
5. Nitrogen Cycle: Nitrogen moves from
the air to the soil, into living things and
back into the air.
a. The Earth’s atmosphere is made up
of 78% nitrogen.
b. Nitrogen in the air is N2. It is two
nitrogen atoms bonded together.
Organisms cannot use nitrogen in this
form.
c. Nitrogen Fixation: when N2 is
combined chemically with other
elements. Once this happens, it can be
used by organisms.
i. Bacteria found in the nodules
found on the roots of legumes can fix
nitrogen.
ii. Once nitrogen is fixed organisms
can use it to build proteins and other
complex compounds.
iii. Decomposers return nitrogen
compounds to the soil.
iv. Bacteria breaks down nitrogen
compounds to release free nitrogen.
Chapter 7, Lesson 5: How do
Ecosystems Change?”
I. Natural Changes- take place in
ecosystems
A. Can take place very quicklynatural disasters
B. Can take place slowly, over
time- Climate change or
succession
1. Succession-A series of
predictable changes that
occur over time
a. Succession occurs
because organisms affect
their environment
b. Types of succession
1. Primary successionthe gradual growth of
organisms in an area
that was previously
bare, such as rock. (For
example lichens,
mosses, and ferns will
first appear on bare
rock.)
2. Secondary
succession-is the series
of community changes
which take place on a
previously colonized,
but disturbed or
damaged habitat.
Examples include areas
which have been
cleared of existing
vegetation (such as
after tree-felling in a
woodland) and
destructive events such
as fires.
c. Secondary succession is
usually much quicker than
primary succession for the
following reasons:
1. There is already an
existing seed bank of
suitable plants in the
soil. (SEEDS EXIST
IN THE SOIL)
2. Root systems
undisturbed in the soil,
stumps and other plant
parts from previously
existing plants can
rapidly regenerate.
(PLANTS ALREADY
THERE CAN EASILY
GROW)
3. The fertility and
structure of the soil has
also already been
changed by previous
organisms to make it
more suitable for
growth and
colonization. (SOIL IS
ALREADY FERTILE)
II. Human Activities Cause Changes in
Ecosystems
A. Harmful Activities- clearing
land, polluting the environment,
and introducing new species into
areas
1. Landfills were thought to
be helpful by reducing odors
and health hazards, but they
harm the environment by
changing the land
2. Ranching and FarmingOvergrazing
3. Burning fossil fuels
B. Helpful Activities- Cleaning
up oil spills, recycling, conserving
C. Preventing damage to
ecosystems- Being informed
about the environment and the
way ecosystems work-BE
AWARE and AVOID ACTIONS
THAT CAUSE HARM