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Unit 2: Biology - Sustainability of Ecosystems (24 hours) |
Students will investigate factors that affect ecological systems and the consequences of changes in these factors. Relationships between ecological balance and the sustainability of life will be studied.
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Ontario
Curriculum objectives: |
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Text: Science
10, Nelson
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Lesson One |
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Summary: (U6) |
Homework: |
BIOLOGY
A Title
Page should be added to students notebook, including: Your name, Your Teacher,
SNC 2DO, Year, Home Form
This should be made at home and will allow for prompt return of any lost
notebooks.
A Table of Contents will be added to notebooks, with the following headings:
Title Date Page
Number
Every day ONLY ONE entry will be made into the table contents under the title
of the first note given.
Every page in the students notebook should also include a date and a page
number.
This includes assignments, tests and labs which may be numbered when the
teacher returns them.
These should be placed near the relevant notes and not in a separate part of
the notebook.
DEFINITIONS
Science: study of natural and physical phenomenon
Biology:
study of life
Ecology:
study of interaction of different species in the environment living with
non-living
Community: the living things interacting in a certain area
Ecosystem:
living and non-living things interacting in certain area eg. home, forest,
pond
FOOD CHAINS
-food chain shows flow of energy through these organisms (arrow shows flow of energy)
seed-->rat-->cat
This food chain indicates that a seed is eaten by a rat, which is then eaten by
a cat
-food
chains show one possible pathway of energy, while a food web shows many
pathways
seed-->rat-->cat
grass-->
-->dog
This food web indicates that a rate ate both grass and seeds and could be eaten by both a cat or dog
ECOLOGICAL TERMS
omnivore:
organism that eats both plants and animals e.g. raccoon, human, black bear
herbivore:
organism that eats plants e.g. cow, horse, deer
carnivore:
organism that eats animals e.g. cat, dog, shark, polar bear
decomposer:
small organism that feeds on/ breaks down dead organisms e.g. fungi, bacteria
scavenger:
larger organism that feeds on dead organisms e.g. crow
predator:
organism that hunts and eats an animal
prey:
animal that is hunted/eaten by a predator
consumer/heterotrophs: organism that eats others for food (e.g.
animals)
producer/autotrophs:
organism that makes it's own food (e.g. plants)
niche: role of organisms in the environment
(eg. bunny eats carrot, feeds wolf, makes more bunnies)
habitat:
where an organism lives (eg. bunny lives in burrow)
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Lesson Two |
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Summary: (U6) |
Homework: |
FACTORS
IN AN ECOSYSTEM
Ecosystems consist of living and non-living things interacting in a certain
area
Biotic Factors: The living things in an ecosystem are
called biotic. These factors also include dead material that is decaying
Abiotic
Factors: The non-living things in an ecosystem are called abiotic. (e.g. wind,
light, temperature, moisture, soil)
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Lesson Three |
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Summary: (D3,D5) |
Homework: |
PYRAMIDS
Pyramid of Numbers: constructs which show numbers of organisms
in each level of food chain
-usually
numbers decrease as one moves up food chain
eg.
10 000 blades of grass are eaten by locust which are eaten by 5 birds
5 birds
900 ants
10 000 grass
These constructs do not produce a proper pyramid in all cases
e.g. a tree is consumed by 4000 caterpillars which are eaten by 5 birds which
are preyed on by 1500 lice
1500 lice
5
birds
4000
caterpillars
1
apple tree
Pyramid
of Biomass: constructs that show the total mass of organisms, and works
better to show energy flow
eg.
using the total masses of the organisms in the previous pyramid of numbers, a
pyramid of biomass would be:
2 kg lice
15
kg birds
200
kg caterpillars
2000
kg apple tree
Pyramid
of Energy: constructs that show the total energy of organisms in a food
chain
-these are the best way to show flow of energy through a food chain
eg.
1 kJ lice
10
kJ birds
100
kJ caterpillars
1000
kJ apple tree
approx. 90% energy is lost with each transfer in the food web (remember the
second law of thermodynamics)
DO FOOD CHAIN ACTIVITY
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Lesson Four |
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Summary: (U1,U7,D2,D5) -summarize photosynthesis/respiration |
Homework: -read p.32 |
ENERGY FLOW
ENERGY: ability to do work (stored energy is called potential energy)
Two Laws
of Thermodynamics
-Energy is not created or destroyed, it just changes forms in a closed system
-Energy tends to become the most random form (thermal...heat)
Energy
way be lost from the earth because it is not a closed system...
Two
examples of energy changing forms:
photosynthesis:
sunlight
energy is converted into sugar (stored chemical) energy
red + blue
light + 6CO2 + 6H2O ------> C6H12O6
+ 6O2 + heat
red
and blue light + carbon dioxide + water -> sugar + oxygen + heat
cellular respiration:
sugar
(stored chemical energy) is converted into ATP (useful chemical energy)
C6H12O6
+ 6O2------> 6CO2 + 6H2O
sugar
+ oxygen -> carbon dioxide +water
Energy flow on Earth
Sun light (radiant
energy) hits producers
(some heat is lost)
Sugar
(from photosynthesis) is made in producers
(some heat is lost from producer)
1o
consumer obtains energy by eating the producer
(some heat is lost from 1o consumer)
2o
consumer obtains energy by eating the 1o consumer
(some
heat is lost from 2o consumer)
Top
consumer obtains energy by eating the 2o consumer
(some
of the top consumers heat lost from earth)
(remember: the earth is not a closed system)
-do
“life in the soil” microviewer
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Lesson Five |
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Summary: (U1) |
Homework: |
SOLAR ENERGY
Solar energy: Sunlight (radiant energy) is turned into sugar (stored chemical energy) in plants
Photosynthesis:
red
+ blue light + 6CO2 + 6H2O ------> C6H12O6
+ 6O2 + heat
red
and blue light are added to carbon dioxide and water to produce sugar, oxygen and
heat
-only
0.023% of suns light energy is converted into sugar energy
44%
of light heats the earth
1%
of light creates wind
25%
of light causes water to evaporate
30%
of light is reflected back off the earth
Percentage
light reflected off the earth is called the ALBEDO
light
is reflected best off...sand, snow, clouds...this results in cooling of earth (as less heat energy
is absorbed)
hot weather -->causes water evaporates to form clouds
clouds
---> increase albedo, as light is prevented from hitting the earth
high
albedo ---> cool earth
cool
earth ---> clouds condense
less
clouds ---> hot weather.....CYCLE REPEATS
Aside:
-the albedo produced by snowfall is thought to be responsible for a cyclical
pattern of ice ages that have occurred in the past
-these cycles of ice ages began approximately 40 million years ago most likely
because of the rise of the Panama Isthmus and the Himalayas which disrupted
ocean currents and air flow.
The Panama Ismthmus prevented warmer currents flowing between the Atlantic and
Pacific ocean resulting in cooling.
The
Himalayas blocked cooled air and blocked winds resulting in the cool air
flowing towards North America.
As snowfall increases, albedo increases which causes more snowfall resulting in
an ice age.
Previous to 40 million years ago, even the Antarctic was able to support plant
life and was not covered with snow even though it was located at the South
Pole. Evidence for this is found in the fossil record.
An earlier ice age (2.2 billion years ago) produced freezing all over the
earth, most likely because of lack of green house gases which help the planet
retain heat.
NUTRIENT CYCLES
Unlike energy, nutrients are not lost from the earth and flow are able to move in cycles
Complete water cycle descriptions and fill out worksheets on the water cycle.
Carbon
cycle
-organic
carbon is found in sugar (photosynthesis, cellular respiration) and used for
life functions
-organic
carbon is also found underground as peat, coal (crushed plants) and oil
(crushed animals)...FOSSIL FUELS
-inorganic
carbon is mostly found in ocean as CO3-2, and HCO3-1
-some
inorganic carbon is also found in the earth’s crust (eg. limestone produced by
crushed animals) and a little as
atmospheric CO2 (carbon dioxide)
Combustion
of fossil fuels produces CO2 + H2O and can produce
C and CO
Humans
impact carbon cycle by combustion of fossil fuels leading to more CO2 in
the air
Humans
are also responsible for removing plants which results in less CO2 removed
from air by photosynthesis
These human activities result in an increase in atmospheric CO2 by
a rate of 1% every four years and could result in global warming
Do
carbon cycle sheet
Lesson Six
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Summary: (U2,U3) |
Homework: |
NITROGEN CYCLE
-nitrogen
is a nutrient used to make protein which is a major part of all living things
-most
of the air is N2 (nitrogen gas)
-nitrogen
is only useful as NO3- (nitrate) to make protein
Nitrogen
Fixing =making nitrogen compounds into useful NO3-
Lightning
produces (fixes) nitrates in air, which plants absorb from rainwater
Bacteria
in some plants fix nitrogen into nitrates inside "nodules" in plants eg. clover,
soybeans, peas, alfalfa
Decomposers
make nitrates from detritus (fertilizers)
Denitrification
–some bacteria make nitrates into nitrites and then nitrogen gas, returning it
to air
Nitrates
are also lost from soil by leaching away with water
Examine
pictures on pg.66-67
Complete
nitrogen cycle diagram using the text
PHOSPHORUS CYCLE
-phosphorus
is a nutrient used to make DNA (genetic material) needed by all living things
Complete phosphorus cycle diagram using the text
BIOACCUMULATION/BIOAMPLIFICATION
-as nutrients are consumed, so are toxins/poisons (eg. pesticides)
-some
toxins are released in urine or sweat
-small
amounts of fat soluble (dissolve in fat) toxins build up in body fat of
consumers
-secondary
consumers eat many of these, and build up even more toxin
-each
higher trophic level (feeding level...eg. producers, consumers) builds up more
and more toxin
-top
trophic level (top consumer) has the greatest buildup of toxin
...this
buildup is called bioaccumulation (page 54)
eg.
peregrine falcons bioaccumulate DDT (pesticide) by this process, and produce
thin egg shells, resulting in
near extinction of this species.
(now DDT is banned because of it's damaging effects)
-insecticide resistance develops if there are any survivors of the initial
insecticide spraying (page 55)
-these insects pass on the genetic differences that allowed them to survive to
their offspring
-this ensures that the next generation of insects will be insecticide resistant
Do worksheets on cycles
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Lesson Seven |
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Summary: (U4,U5,U8) |
Homework: -complete soil lab |
SUSTAINABLE ECOSYSTEMS
Sustainable
ecosystems exist in equilibrium (balance) where natural resources are conserved, preserved and
restored
-biodiversity
(a variety of species) is maintained within a sustainable ecosystem as biotic
and abiotic factors interact
ABIOTIC INFLUENCES
ON SUSTAINABLE ECOSYSTEMS
(I) SOIL
Soil is
the material found on the top layer of the earth and has variable composition
Clay: soil with a diameter of approximately 0.002 mm
Silt:
soil with a diameter of approximately 0.05 mm
Sand:
soil with a diameter of approximately 1.00 mm
Loam:
soil with a mix of clay, silt and sand
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SOIL |
Infiltration |
Water Holding |
Aeration |
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SAND |
Good |
Poor |
Good |
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SILT |
Medium |
Medium |
Medium |
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CLAY |
Poor |
Good |
Poor |
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LOAM |
Medium |
Medium |
Medium |
%
Mass of sand, silt and clay is determined by separating using two sizes of
sieves
Masses
each of three types of soil are then measured on a balance
Mass of soil type/Total mass of soil X 100 = % Mass of each soil type
Use a soil triangle chart to find type of soil you have
Soil
terms:
Percolation: water loss from soil, more common in sandy soil (poor water
holding)
Leaching:
loss of water soluble materials from the soil as water carries the material
when it percolates
Humus:
partially decomposed matter at soil surface (mixed by animals)...black
LEACHING
Leaching:
loss of nutrients in the soil and build up in water
ground water – melted snow/rain moves into the soil via gravity
percolation
– movement of water through the soil
water
table – an area of soil saturated (full) of water (higher after rainfall)
leaching results when nutrients dissolve into groundwater and go down to water
table
-plants
send roots down to get nutrients from water table
-too much of these nutrients may be harmful/toxic
-some nutrients end up in well water (drinking) and some goes to lakes and
rivers, which may harm animal/plant life
Work on soil lab using dirt, sand and marble to examine water holding capacity
of different sized soil
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Lesson Eight |
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Summary: (U4,U5) |
Homework: |
(II)LIGHT
light
consists of wavelengths of electromagnetic radiation
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visible light ranges from wavelengths of red=700nm to violet=390nm
red-orange-yellow-green-blue-indigo-violet (roygbiv)
Infra
red light has a larger invisible wavelength (heat produces infra red)
Ultra
violet has smaller invisible wavelength (sun produces ultra violet)
LIGHT
FACTORS IN ECOSYSTEMS:
(a)
Intensity: brightness of the light
Plants need certain intensities of light in order to carry out photosynthesis
formula for photosynthesis: red/blue light + carbon dioxide + water produce
sugar + oxygen
Compensation
Intensity – light is just bright enough to allow photosynthesis...below this
level, plants will die
Saturation
Intensity – maximum amount of light needed for food production...more light will
not produce more food
Shade
tolerant plants have low saturation intensity (allows growth on forest floor),
eg. fern, moss, maple seedlings
Behavioural
responses to light intensity:
Tropism –directional movement of plants
Positive
phototropism –movement towards light eg. stem
Negative
phototropism –movement away from light eg. root
Nastic movement –non-directional movement, eg. flower opens in light
Taxis –directional movement of animals
Positive
phototaxis –movement of animals towards light eg. insects at night
(b) Duration:
the length of time organisms are exposed to light
The
length of daily exposure to light is called the photoperiod
Plant
photoperiod
-certain plants grow best in long days (14 h) eg. oats, clover (arctic and mid
summer growth)
-other
plants prefer shorter days (10 h) eg. perennials like tulips (equatorial, early
spring growth)
Animal photoperiod
-light duration controls migration, sleep patterns, mating habits in some
species
(eg.
geese sometimes fly north in a blizzard because the day length has increased)
(c) Quality:
the colour of light
Red and blue light are used by plants to carry out photosynthesis with the aid
of chlorophyll (green pigment)
Practice use of photometer
Examine
microscope slides of plants from different ecosystems
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Lesson Nine |
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Summary: (U4,U5) -prepare buckets for field study |
Homework: |
(III) TEMPERATURE
Temperature is a measure of the heat content in a body
Extreme temperatures result in dormancy followed by death
Organisms
function best at certain "optimum temperatures"
Plant optimum temperatures
–photosynthesis occurs best at 30oC
At lower temperatures the rate of photosynthesis decreases as molecules slow
down
Above
this temperature photosynthesis usually stops as molecules break down due to
the heat
Germination (opening of seeds) often occurs after cold weather (spring) in
order to ensure longer
growing
season.
-temperature
influences fruit and flower growth as well
-plants
survive cold weather with dormancy
Animal
optimum temperatures
-poikilotherms (cold blooded) -temperatures of the organism is similar to the
environment, change
(eg.
reptiles)
-homeotherms
(warm blooded) –temperature of the organism is constant (eg. humans are 37oC)
(IV) WIND
Wind is
the movement of air
Good effects of wind:
–moisture is blown inland
-plant
pollen, seed, fungus spores are moved to help with reproduction
Bad effects
-erodes soil
-blows
off vapour needed for life
-blows
trees over
(V) MOISTURE
Moisture
is the water present in an ecosystem
Precipitation: rain, snow etc. that brings moisture into an ecosystem
Relative
Humility: % of water in the air
eg.
if the air has 100% relative humidity, no more water can evaporate into the air
Transpiration:
leaves lose water in stoma (openings) on the bottom of leaves
Plant responses to moisture levels:
-deciduous plants drop leaves in order to conserve water during winter, dry
seasons
-coniferous
plants use modified leaves to conserve water and do not drop leaves
Animal responses to moisture levels:
-some animals have exoskeletons to prevent water loss (eg. insects, shellfish)
-some animals have waterproof skin to conserve water (e.g. humans)
-some animals stay in moist areas in order to conserve water (e.g. earthworms)
Use pg. 26 of Nelson 10 to design and build wind meter
Do Peregrine falcon summary paragraph
Assemble
buckets for next day. Buckets should contain:
-bug net
-thermometer
-soil
scooper
-trowel
-wind
meter (made last class)
-meter
stick
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Lesson Ten |
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Summary: (U7,D2,D5) |
Homework: |
FIELD STUDY
Do field
study in back woods
Write
up answers (in full sentences) for field study
Some
terms needed in the field study:
Independent variable...a factor chosen for study by the experimenter
dependent
variable...a factor influenced by independent variable during an experiment
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Lesson Eleven |
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Summary: (R2) |
Homework: |
ONTARIO FIRST NATIONS
Two
major Native groups lived in different areas of Ontario, and had different
season lifestyles:
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IROQUOIS |
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ALGONQUIN |
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Southern Ontario- warmer, less rock |
Middle Ontario- moderate, some rock |
Northern Ontario- colder, rockier |
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Carolinian forest |
Canadian shield/Carolinian forest |
Canadian Shield |
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Iroquois language spoken |
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Algonquin language spoken |
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5 nations present (later 6) |
Huron, Ottawa present |
Ojibwa, Nipissing present |
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SPRING IN THE SOUTH |
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SPRING IN THE NORTH |
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planting of three "sister" crops occurs |
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tapping of maple sugar occurs |
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SUMMER IN THE SOUTH |
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SUMMER IN THE NORTH |
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farm the "three sisters" |
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gather stone for tools, weapons |
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FALL IN THE SOUTH |
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FALL IN THE NORTH |
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harvesting of crops |
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nets used for catching whitefish in lakes |
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WINTER IN THE SOUTH |
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WINTER IN THE SOUTH |
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consume crops, stay put |
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go north for hunting on ancestral hunting grounds |
-in
1318-1320, a "little ice age" started when massive flooding caused a
period of cooling in North America
-both
Algonquin and Iroquois moved southward for a few hundred years instead of adapting to the new
environments in their area, then moved back when the climate warmed up.
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Lesson Twelve |
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Summary: (R5) |
Homework: |
NORTHERN CONIFER FOREST
-view
video on Northern Conifer Forest
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Lesson Thirteen |
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Summary: (D7) |
Homework: |
HIEARCHY OF LIFE
HIERARCHY
OF LIVING THINGS: a construct to arrange organisms from smallest and simplest
to largest and most complex
Cells
–smallest things with all characteristics of life
(1)Organisms
–able to carry out life functions on own
-unicellular organisms: must live as single cells eg. bacteria, amoeba
-simple multicellular organisms: may live as single cell or in groups, eg.
slime mold
-complex multicellular organisms: must live as group of cells, eg. rabbit, dog,
human
(2)
Population –number of one species that live in one area at one time
(3)
Ecosystem/Community –group of populations interacting with abiotic factors
(small area)
(4)
Biome –group of ecosystems with characteristic climate and populations (large
area)
(5)
Biogeographical region –large area with many biomes, continent
(6)
Biosphere –surface of planet with living organisms
BIOTIC
POTENTIAL / ENVIRONMENTAL RESISTANCE
Biotic
Potential: maximum population size that can be maintained
immigration –individuals entering the population from other areas
natality
–birth rate
Four factors affect birth rate:
1) Birth potential
–number of babies per birth
2) Number of offspring
likely to survive to have offspring of their own
3) Procreation- number
of times reproduction occurs per year
4) Length of
Reproductive life- number of years an individual can reproduce (e.g. elephants-
75 yrs)
Environmental
Resistance: factors decreasing population size such as...
mortality –death rate
emigration
–individuals leaving the population to other areas
Review Graphing Rules....
Do
Biotic Potential/Environmental Resistance activity
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Lesson Fourteen |
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Summary:(D7,R6) |
Homework: |
In ecosystems, populations interact with each other and abiotic
factors
Populations
staying the same/balanced = EQUILIBRIUM (homeostasis)
Populations
are DYNAMIC, going up and down in size
Populations
which go up and down in cycles have DYNAMIC EQUILIBRIUM
OH DEER
Play
"Oh Deer"
complete and hand in "Oh Deer"
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Lesson Fifteen |
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Summary:(D7) |
Homework: -test next class, lessons #1-13 |
POPULATION TERMS
In ecosystems, populations interact with
each other and abiotic factors
Populations
staying the same/balanced = EQUILIBRIUM (homeostasis)
Populations
are DYNAMIC, going up and down in size
Populations
which go up and down in cycles have DYNAMIC EQUILIBRIUM
Carrying capacity: theoretical maximum number of individuals an
environment can support without being harmed
Critical
number: a number of organism below which will result in the extinct of a
species
threatened species: populations that are declining rapidly
endangered
species: populations close to critical number
Recruitment rate: amount of a species that are able to reach reproductive age
k-strategy organisms: few offspring are produced, but most reach reproductive
age.
-better
for stable environments (eg. humans)
r-strategy: many offspring are produced, but few reach reproductive age.
-better
for unstable environments (eg. spiders)
Work on lynx and rabbit graph and chart for population activity
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Lesson Sixteen |
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Summary: |
Homework: |
ECOLOGY TEST
ECOLOGY TEST on lessons 1-13
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Lesson Seventeen |
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Summary:(U5,U7,D3,D5) |
Homework: |
BIOGEOGRAPHY
-climatograms:
charts that compare temperature and moisture
-these
two abiotic factors determine the plant life that will grow in an area
(plants
will in turn determine type of animal life that will be found in this area)
-do pg. 94, (d), (e), (f), (g), (h)
BIOMES
FOUND IN CANADA