Transcript 1.1 The Study of Life

1.1 The Study of Life
KEY CONCEPT
Biology is the study of all forms of life.
1.1 The Study of Life
• 1.1 Objectives
– Students will be able to define and give examples of
Earth’s biodiversity.
– Students will be able to summarize the characteristics
that all living things share.
– Students will be able to summarize and give examples of
the four major unifying themes of biology.
1.1 The Study of Life
Earth is home to an incredible diversity of life.
• The biosphere includes all living things and all the places
they are found.
biosphere = everywhere life exists
1.1 The Study of Life
Earth is home to an incredible diversity of life.
• Every part of the biosphere is connected with every other
part.
• The biosphere includes many environments.
– land environments
1.1 The Study of Life
• The biosphere includes many environments.
– saltwater and freshwater environments
Tidepool
Estuary
– portions of the atmosphere
1.1 The Study of Life
• Biodiversity is the variety of life.
– Biodiversity generally increases from the poles to the
equator.
– Biodiversity is greater in areas with consistently warm
temperatures.
Biodiversity is
greater closer to
the equator.
1.1 The Study of Life
• A species is one particular type of living thing.
– Members of a species can interbreed to reproduce.
– There are about 2 million different living species
have been identified.
1.1 The Study of Life
All organisms share certain characteristics.
• Biology is the scientific study of all forms of life.
1.1 The Study of Life
• An organism is any individual living thing.
– All are made of one or more cells.
1.1 The Study of Life
• An organism is any individual living thing.
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All are made of one or more cells.
All need energy for metabolism.
All respond to their environment.
All have DNA that they pass on to offspring.
1.1 The Study of Life
1.1 Review
1. How are species related to the concept of biodiversity?
2. How do the characteristics of living things contribute to
an organism’s survival?
3. What is the relationship between cells and organisms?
4. How does biodiversity depend on a species’ ability to
reproduce?
5. You respond automatically to many different stimuli,
such as loud noises. Why might a quick response to a
sound be important?
1.1 The Study of Life
1. How are species related to the concept of biodiversity?
• Biodiversity is the variety and number of species in a
given area.
1.1 The Study of Life
2. How do the characteristics of living things contribute
to an organism’s survival?
• The cells that are the basic unit of life carry out the
functions needed to support and maintain life, for which
they require a continual supply of energy. The ability to
respond to the environment helps an organism to avoid
injury and death, as well as meet material needs.
Reproduction and development enables species survival.
1.1 The Study of Life
3. What is the relationship between cells and
organisms?
• All organisms are made of one or more cells, which are
the functional units of life, carrying out activities that
support life.
1.1 The Study of Life
4. How does biodiversity depend on a species’ ability to
reproduce?
• Without the ability to reproduce, a species would become
extinct, which would lead to a decrease in biodiversity.
1.1 The Study of Life
5. You respond automatically to many different stimuli,
such as loud noises. Why might a quick response to a
sound be important?
• A quick response could protect against hearing damage
or a physical threat.
1.12 The Study of Life
KEY CONCEPT
Unifying themes connect concepts from many
fields of biology.
1.12 The Study of Life
All levels of life have systems of related parts.
• A system is an organized group of interacting parts.
– A cell is a system of chemicals and processes.
– A body system includes organs that interact.
– An ecosystem includes living and nonliving things that
interact.
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• Biologists study many different systems.
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Structure and function are related in biology.
• Structure determines function.
– Proteins with different structures perform different
functions.
– Heart muscle cells have a different structure and
function than stomach muscle cells.
– Different species have different anatomical structures
with different functions.
1.12 The Study of Life
Organisms must maintain homeostasis to survive in
diverse environments.
• Homeostasis is the maintenance of constant internal
conditions.
1.12 The Study of Life
• Homeostasis is the maintenance of constant internal
conditions.
– Homeostasis is usually maintained through negative
feedback.
– Negative feedback systems return a condition to its
normal (set) point.
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• Behaviors and adaptations can help maintain
homeostasis.
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Evolution explains the unity and diversity of life.
• Evolution is the change in living things over time.
– The genetic makeup of a population of a species
changes.
– Evolution can occur through natural selection of
adaptations.
– Adaptations are beneficial inherited traits that are
passed to future generations.
1.12 The Study of Life
• Evolution accounts for both the diversity and the unity of
life.
1.12 The Study of Life
1.2 Review
• Describe a biological system.
• Give an example of how structure is related to function in
living things.
• Why is homeostasis essential for living things?
• What is the relationship between adaption and natural
selection?
• How are structure and function related to adaption?
• How is the process of natural selection involved in
evolution?