What is the core theme of biology?
Evolution
The process of change that has transformed life on Earth
7 Characteristics of Life
10 Levels of Biological Hierarchy (Biggest level to smallest level)
Biosphere
all environments (everything) on Earth
Ecosystem
all living and nonliving things in a particular area
Community
all organisms (living things) in an ecosystem
Population
all individuals of a species in a particular area
Organism
an individual living thing (one single organism)
Organs and Organ Systems
specialized body parts made up of tissues. Ex: heart, stomach
Tissue
a group of similar cells
Cell
life’s fundamental unit of structure and function. (cells are alive)
Organelles
a structural component of a cell (building blocks of a cell)
Molecule
a chemical structure consisting of atoms
Emergent Properties
new properties that arise with each step upward in the hierarchy of life owing to the arrangement and interactions of parts as complexity increases.
Emergent properties characterize nonbiological entities as well.
Ex: Bike
Emergent Properties- put them/things together
Reductionism
is the reduction of complex systems to simpler components that are more manageable to study.
Ex: the molecular structure of DNA v. heredity
An understanding of biology balances reductionism with the study of emergent properties.
Reductionism- breaks things apart
Life requires energy transfer and transformation
Living organisms transform energy from one form to another
food (chemical energy)»_space; motion (kinetic energy)
Two Rules of Ecosystem Dynamics (how they work)
The two major processes that the dynamics of an ecosystem include
2. Energy flows- usually enters as sunlight exits as heat
Structure and Function of living organisms
are closely related.
By looking at the structure we can figure out the function.
The fundamental unit of life
Cell
The lowest level of organization that can perform all activities required for life (Order, evolutionary adaptation, response to the environment, reproduction, growth and development, energy processing, regulation)
The Cell
All Cells
- use DNA as their genetic material (inside part)
Two main forms of cells are
Eukaryotic Cell and Prokaryotic Cell
Eukaryotic Cell
has membrane-enclosed organelles, the largest of which is usually the nucleus
(have internal membrane)
Prokaryotic Cell
is simpler and usually smaller, and does not contain a nucleus or other membrane-enclosed organelles
(doesn’t have internal membrane. normally much smaller)
(bacteria)