|
| |
Chapter 3 Notes
Change in the Biosphere
3-1. The Changing Environment
A. Changes in the Lithosphere
1. Tectonic Plates: Large moveable plates that compose the
lithosphere.
a. Density: Ratio of mass to volume (D = m/v).
1) Materials float on materials with a greater density.
2) Ice floats on water
3) Steel bolts float on mercury.
4) *Tectonic Plates float on magma.
a) Magma: molten (liquid) rock
b) The effect is much like wood on water. The top layers of
earth (lithosphere) float on the more dense magma.
b. Viscosity: the ability of a liquid to be poured.
1) Examples of Viscosity in the kitchen.
a) Oil, Water, Grease, Syrup, Molasses
2) Most often referred to as weight, as in the weight of an oil.
a) The more viscous a liquid is the thicker (harder to pour)
the liquid is.
3) Temperature affects the viscosity: As temperature goes up the
viscosity goes down.
4) *Magma is very viscous (hard to pour). The effect of this is
that the continents move very slowly. Usually no more than 1"
per year.
c. Types of Plate Interactions
1) Sea Floor Spreading: Molten material reaches the
surface and moves two plates apart. New land is formed (usually
underwater), called mid-ocean ridges.
2) Transformed Faults: Two plates slide past each other.
Earthquakes are common with this kind of fault. The San Andreas
fault in California is an example.
3) Subduction: One plate slides under another plate.
Pressure and friction cause the lower plate to melt, resulting in
earthquakes and volcanic activity. –Volcano
Video
a) Social Studies Link; pg 35
4) Plate Collisions: Two plates collide head on. This causes
uplifting, which results in mountains rising and earthquakes. The
Himalayas were formed this way.
2. Pangaea: a super-continent when all of the continents were once
joined. Over a long period of time the plates have moved apart into the
continents we now know.
3. Weathering: The breaking down of rocks by weather and water.
a. Erosion: Material that is broken-down is carried off by the
rain.
1) Wind Erosion
2) Water Erosion
b. Break Up of Rock:
1) Freeze/Thaw Cycle: water gets into cracks and then
freezes during the winter, thaws, then freezes again and again.
2) Plant Growth: Plants grow in small crevasses. As the
plant gets larger the roots expand putting pressure on the rocks.
3) Heat/Cool Global Cycle (Ice Ages): The planet has gone
through ice ages in the past where huge glaciers were formed and
scraped the earth as they moved.
B. Changes In the Hydrosphere:
1. Ice Age: long periods of cooling during which huge glaciers
grow and extend from the Earth's polar regions covering much of the planet's
surface.
a. Glacier: Huge layer of ice which moves very slowly across
the Earth.
1) Glaciers are formed because of extremely cold temperatures.
2) As glaciers move they are very heavy and scrape the Earth.
They carry the soil with them until they melt and drop the soil.
3) Activity 3.2 pg 47: What happens when glaciers move?
b. Scientists have found evidence of five different ice ages.]
1) No one knows why the ice ages come.
2) Some believe that there are periods of global cooling which
start it and others that the Earth wobbles on its axis.
2. El Niño: Unusual currents which last for several months.
a. Normally toward the end of December the flow of warm,
nutrient-poor water lasts for a few weeks. During El Niño this will
last for several months.
1) This affects the fish because of the change of temperature and
lack of nutrients.
2) A drop in fish causes a drop in fishing industries and
increased cost for other industries that depend on fish meal.
3) No one knows exactly what causes the El Niño effect.
4) Dateline 1982; pg 36
3. La Niña: The opposite of El Niña.
4. Issue: The Mississippi Rive; Pg 41
C. Changes in the Atmosphere: Lab 1: The
Atmosphere and Living Things
1. Basic Changes:
a. Each day temperatures change because of the rotation of the Earth.
b. Each season climate changes. This is caused by a rotation in
Earth's axis.
2. Effect of life on atmosphere:
a. Scientists hypothesize that before there was life on the planet
there were many gases in the atmosphere. Water vapor, carbon dioxide,
and sulfur gases were released from erupting volcanoes. Eventually
organisms formed that could combine water, carbon dioxide and the energy
in sunlight to produce food in a process we call photosynthesis.
1) Photosynthesis: changing energy from the sun to glucose
(sugar) and changing carbon dioxide into oxygen.
b. Oxygen, carbon dioxide, water, and nitrogen are continuously
cycling in and out of the atmosphere.
c. Much of the carbon is stored in living and long-dead organisms.
When we burn it as a fuel it releases carbon dioxide gas.
d. Examples of the effects of organisms on the environment.
1) Greenhouse Effect: An increase in CO2
concentrations is thought to reduce the amount of heat lost from
Earth to outer space. It is hypothesized that this will cause the
temperature of the Earth to go up.
2) Ozone Hole: Increased pollutants in the troposphere are
theorized to cause a hole in the ozone layer. Refrigerants are the
main concern.
3. Effects Abiotic Factors on the Atmosphere:
a. Volcanic eruptions continue to send gases into the atmosphere
where winds carry them around the world.
b. Wild fires send gases into the atmosphere.
c. Natural decomposition of living materials, and by-products of
animals send gases into the atmosphere.
D. Pg 37 #1-3
3-2. Needs of Organisms
A. Water:
1. The presence of fresh water is one of the most important factors in
the ability of land to support life.
a. Water is necessary for both plant and animal life.
b. Rainfall directly affects the abundance of life in an area.
c. Link; Pg 38
2. Fish and aquatic organisms are often affected by various factors:
a. Temperature, pH, nutrients, dissolved oxygen, chemicals, and
number of organisms in the water.
b. Chemical pollutants also affect water quality: pollution mercury,
lead, industrial and domestic waste.
c. Concentration of oxygen is also a factor for aquatic life.
Oxygen's solubility in water decreases with temperature, therefore warm
waters cannot contain as much oxygen as cold water.
B. Food and Energy
1. Almost all energy comes from the sun, either directly or indirectly.
a. The only exceptions are nuclear energy and energy from the core of
the Earth.
b. Plants and algae make food by capturing energy from the sun during
photosynthesis.
c. Animals get energy from eating plants, or eating animals who have
eaten plants.
d. Nutrients: all of the substances that an organism requires from
food. Minerals, vitamins and other necessary chemicals are nutrients.
e. Do It Field Activity: Pg 38
2. Hidden Dangers: Some substances are stored and can build up in the
cells of the body's tissues.
a. If a stored substance is harmful the tissues can become poisonous
if eaten by other animals.
b. This buildup of poisonous materials in tissues allows poisons in
the environment to pass from one organism to another.
c. Biological Magnification: The magnifying effect of poisons
in a food chain.
C. Living Space
1. All organisms need space to live.
a. They need a location with sources of food.
b. They need a location with water.
c. They need space to exist.
1) Plants require a certain amount of space to obtain light and
grow roots.
2) Animals need space in which to seek food, water, shelter and
mates.
a) Territory: an area that is claimed as a living
space by an individual animal or group of animals.
b) Many territorial animals mark their areas with scents to
let intruders know that the area is off limits.
c) Some animals defend their territories with sound or
gestures.
d) The size of an animal's territory is determined by the
needs of that animal. If there is not enough space for all the
members of a population, they will compete for a territory,
often to the death.
e) Think About It, Pg 39
D. Climate
1. Body Temperatures:
a. Ectotherm: Animal where the temperature of the environment
determines the body temperature.
b. Endotherm: Animal whose body temperature is maintained
separately from the environment.
2. Effects of climate changes on organisms.
a. Migration: Animals travel over great distances to have
access to food and warm weather.
b. Hibernation: dormancy in animals. Lowered heartbeat, body
temperature, respiration and the animal enters a sleep-like state. This
low metabolism allows animals to survive a period when there is not
enough food.
c. Plants
1) Dormant: when a plant's life processes slow down during
periods of cold weather.
E. Pg 40 #1-4; Activity 3.1 Pg 42, Environmental Needs of Land Isopods
3-3. The Ecosystem Spot Population Activity
A. Species: a group of
organisms so similar to one another that they can breed and produce fertile
offspring.
1. Habitat: the specific environment in which a particular
species lives.
a. It provides food, shelter and temperature appropriate for the
species.
b. Often when population goes up members of the same species
compete for the same resources (food, water, etc).
2. Geographical range: the total area where the species is
found. Figure 3.6, pg 43
a. How can the elimination of a habitat affect the range of a
species?
3. Dateline 1973; Pg 43
B. Populations and Communities
1. Population: all the members of a species that live in the
same geographical area.
2. Community: all the different populations that live and
interact in the same area.
a. Which is larger, population or community?
C. Ecosystems
1. Ecosystem: all the communities in an area, as well as the
abiotic factors in the environment.
2. Biodiversity: the variety of species in an ecosystem.
3. How would habitat destruction affect biodiversity?
4. Ecology In Action Pg 48; Everglades
D. Pg 44 #1-3
3-4. Chapter 3 Review
A. Pg 45; Define Key Terms, Multiple Choice, Word Comparisons; Concept
Review (CS); Think Critically (CS); Graphic Analysis (CS)
B. Chapter 3 Review WS
|
