Characteristics of living things
Living things are made of cells.Living things obtain and use energy.Living things grow and develop.Living things reproduce.Living things respond to their environment.Living things adapt to their environment.
unicellular
one cell, does not have specialized cells
multicellular
Made up of more than one cell, and has specialized cells
specialized cells
Cells that perform specific functions that benefit the entire multicellular organism
Stimulus
A change in an organism's surroundings that causes the organism to react
response
An action or change in behavior that occurs as a result of a stimulus.
growth
a change in numbers
development
becoming more complex
homeostasis
maintains stable internal environment
cell theory
idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells
Hooke
named cells
schwann
all animals are made of cells
Schleiden
All plants are made of cells
Virchow
All cells come from pre-existing cells
Levels of organization
cell, tissue, organ, organ system, organism
tissues
group of different cells, but perform the same structure and function
virus
nonlivingsmaller than a cellrequires a host
host cell
replicates the viruses DNA
cell
basic unit of life
organ
different tissues