How do we define life?
Properties of Living Things
• Are organized, and are made of one or
more cells (Cellular Organization)
• Maintain stable internal conditions
(Homeostasis)
•Are capable of Reproduction
•Exhibit Growth and development
•Respond to their environment
(Responsiveness)
Properties of living things
(continued)
• Pass traits to offspring (Heredity)
• Use energy. Metabolism is the sum of all
chemical reactions carried out in an
organism.
Stimulus or response?
• The bell rings at the end of a class period
• Your dog runs into the kitchen when you
open a can
• A paramecium backs up and moves away
when it encounters an obstacle.
• A plant grows toward the window
• A baby hears a loud noise
• You pull your hand away after touching the
hot oven
Examples
• Hummingbirds feed almost
constantly to supply energy to
their racing wings and hearts.
• Metabolism, homeostasis
• A butterfly emerges
from a cocoon.
• Growth and
Development
A bacterium divides into new cells
every 15 minutes
• Reproduction
An elephant's large ears allow the
blood in the ears to be cooled by
as much as 10 degrees.
• Homeostasis, responsiveness
•
• A pill bug rolls into a ball
when touched.
• Responsiveness
• Earthworms are made of specialized
cells, such as digestive cells, muscle
cells, skin cells, etc.
• Cellular Organization
•A female frog lays many eggs at a
time
• Reproduction
• A toad burrows
in the mud
during hot
weather to avoid
water loss
• Homeostasis
• Responsiveness
•An amoeba
is composed
of a single cell
•Cellular
Organization
A child inherits cystic fibrosis
from her parents
• Heredity
Mitochondria in a cell release
energy from sugars
• Metabolism, cellular organization,
homeostasis
Branches of Biology
• Biochemistry: chemistry
of life
• Ecology: how organisms
interact with each other
and their environment
• Cell biology: life on the
cellular level
• Genetics: how organisms
pass traits to their
offspring
• Evolution: changes in
organisms over time
• Microbiology:
microscopic
organisms
• Botany: plants
• Zoology: animals