Transcript Presentation

Describe evidence of Species
variation due to :
Climate, changing landfiorms,
interspecies interaction an genetic
mutation.
- Darwin’s Theory
Overproduction and Variation
• Natural selection is the process by which individuals
who are better adapted to their environment are
more likely to survive and reproduce than other
members of the same species.
- Darwin’s Theory
Competition and Selection
• Variations among turtles make some of them
better able to survive. Turtles that survive to
become adults will be able to reproduce.
- Darwin’s Theory
Relating Cause and Effect
• In a graphic organizer, identify factors that
cause natural selection.
Causes
Overproduction: More offspring are
produced than can survive.
Variations: Members of the same species
differ.
Effect
Competition: Offspring compete for survival.
Selection: Some variations make individuals
better fit for survival.
Environmental Change: Changes can affect an
individual’s survival.
Genes: Genes that help determine survival are
passed from parent to offspring.
Natural Selection
- Biogeography
Continental Drift
• One factor that has affected how species are
distributed is the motion of Earth’s continents.
- Evidence of Evolution
Kaibab and Abert’s Squirrels
• These two kinds of squirrels have
been isolated from one another
for a long time. Eventually this
isolation may result in two
different species.
Interactions Among
Living Things
Adapting to the Environment
• Every organism has a variety
of adaptations that are
suited to its specific living
conditions.
Interactions Among
Living Things
Using Prior Knowledge
• Before you read, look at the section headings and
visuals to see what this section is about. Then write
what you know about how living things interact in a
graphic organizer like the one below. As you read,
continue to write what you learn.
1.
1.
2.
3.
4.
What You Know
Organisms interact in different ways.
What You Learned
Organisms are adapted to their environments.
Organisms have niches, which are their roles in their habitats.
Organisms compete for resources. Some organisms eat others, and
this affects the size of populations.
Some organisms live together in symbiotic relationships, of which
there is mutualism (both benefit), commensalism (one benefits, the
other is not helped or harmed), and parasitism (one benefits, the
other is harmed).
- Cycles of Matter
The Water Cycle
• The processes of evaporation, condensation,
and precipitation make up the water cycle.
- Cycles of Matter
The Carbon and Oxygen Cycles
• In ecosystems, the
processes by which
carbon and oxygen
are recycled are
linked. Producers,
consumers, and
decomposers play
roles in recycling
carbon and
oxygen.
- Cycles of Matter
The Nitrogen Cycle
• In the nitrogen cycle, nitrogen moves from
the air to the soil, into living things, and
back into the air.
Graphic Organizer
Free nitrogen is
present in air.
Bacteria release
some free nitrogen
back into the air.
Nitrogen Cycle
Decomposers break
down wastes and
remains of
organisms.
Bacteria in root
nodules fix free
nitrogen into
compounds.
Consumers obtain
nitrogen by eating
plants.
- Energy Flow in Ecosystems
Building Vocabulary
• A definition states the meaning of a word or phrase
by telling about its most important feature or
function. After you read the section, reread the
paragraphs that contain definitions of Key Terms.
Use all the information you have learned to write a
definition of each Key Term in your own words.
Key Terms:
Examples:
energy
pyramid
food chain
food
web
consumer
producers
herbivore
omnivore
carnivore
scavenger
Anaenergy
In
food chain,
pyramid
a consumer
shows how
could
much
be an
energy
herbivore,
moves an
from
omnivore,
one
level tooranother
a carnivore,
in a food
including
web, beginning
a scavenger.
with the
producers.
decomposer
Decomposers are nature’s recyclers.
A few thoughts on pollution:
Conserving
Land and Soil
Soil Management
• Poor soil management can result in erosion,
nutrient depletion, and desertification. The
advance of desert-like conditions into areas
that previously were fertile is called
desertification.
Waste Disposal
and Recycling
The Problem of Waste Disposal
• Billions of tons of municipal solid waste are
created in the United States each year. More
than one third of that waste is paper.
Water Pollution
and Solutions
Water Pollution
• Wastes produced by
households, agriculture,
industry, mining, and
other human activities
can end up in water.
Air Pollution
and Solutions
Indoor Air Pollution
• Some substances that cause indoor air
pollution, such as dust and pet hair,
bother only those people who are
allergic to them. Other indoor air
pollutants, such as toxic chemicals, can
affect anyone.
Air Pollution
and Solutions
Reducing Air Pollution
• The key to reducing air pollution is to control
emissions. A smokestack scrubber removes
pollutants such as sulfur dioxide from
emissions.
Air Pollution
and Solutions
Relating Cause and Effect
• Let us identify three causes of air pollution.
Causes
Factory and power plant
emissions
Effect
Emissions from
automobiles and trucks
Indoor air pollutants
such as toxic chemicals
Air pollution
Global Changes
in the Atmosphere
Ozone Cycle
• When ultraviolet radiation from the sun
strikes an ozone molecule, the ozone molecule
splits into an oxygen molecule and a free
oxygen atom.
Global Changes
in the Atmosphere
Global Climate Change
• The trapping of heat near Earth’s surface is
called the greenhouse effect.