LESSON 1
Biology science
2. Levels of biological organization
3. Criteria for organism classification
Common characteristics of living organisms
5. Evolution
1.
4.
 From the Greek roots:
 Bio: Life
 Logy: Study of
BIOLOGY SCIENCE
Biology is a natural
science concerned
with the study of life
and living organisms,
including their
structure, function,
growth, origin,
evolution,
distribution, and
taxonomy.
SCIENTIFIC THEORY
 General explanation of natural phenomena
 Developed through extensive and reproducible
experiments and observations
LEVELS OF BIOLOGICAL ORGANIZATION
Biosphere
Ecosystem
Community
Species
Population
Multicellular organism
Organ system
Tissue
Cell
Organelle
Molecule
Atom
Biosphere
is a part of the Earth inhabited by living organisms
includes both the living and nonliving components
Ecosystem
 is a system formed by interaction of a community of
organisms with their environment
COMMUNITY
Population:
is a group of individuals of the same species that
occupy the same general area:
+ they rely on the same resources
+ they are influenced by the same environmental factors
+ they have a high possibility of interacting and breeding with each
other
Levels of Organization
Three domains of organisms
Bacteria
Archaea
Eukarya
CRITERIA FOR ORGANISM
CLASSIFICATION
 Cell type:
 Eukaryotic cells
 Prokaryotic cells
 Cell number:
 Unicellular organisms
 Multicellular organisms
 Energy acquisition:
 Autotrophic organisms
 Heterotrophic organisms
HOMEOSTASIS
COMMON CHARACTERISTICS OF ORGANISMS
Response
to stimuli
COMMON CHARACTERISTICS OF ORGANISMS
They acquire energy and materials from the
environment
•Nutrients: from air, water, soil or from other living
organisms
•Energy:
•some organisms can capture the energy of
sunlight
•some consume the energy-rich molecules of other
organisms
COMMON CHARACTERISTICS OF ORGANISMS
Ling things grow and reproduce
COMMON CHARACTERISTICS OF ORGANISMS
Living
things have
the capacity
to evolve
EVOLUTION
Evolution is the unifying theory that can explain the
origin of diverse forms of life as a result of change in
their genetic makeup
THREE NATURAL PROCESSES UNDERLIE EVOLUTION
 Genetic variation
 Inheritance
 Natural selection
Genetic variations
 Genetic variations:
Influence of
 Environment and
lifestyles (rare)
 Genes (main reason):
changes in genes
Inheritance
 Inheritance:
the genetic
transmission of
characteristics
from parent to
offspring
Natural selection
Adaptation: structures, physiological processes or behaviors that aid in survival
and reproduction in a particular environment
Natural selection: tends to preserve genes that help an organism survive and
reproduce