CHAPTER 1 SECTION 1
Themes of Biology
Biology is the
study of life.
All living organisms share certain
general properties that separate them
from nonliving things.
•Properties of Life:
• Cellular organization
• Reproduction
• Metabolism
• Homeostasis
• Heredity
• Responsiveness
• Growth and development
Characteristics of Living Organisms
•Cellular organization – every living thing is
composed of one or more cells.
•Reproduction – all living things are able to
reproduce.
•Metabolism – all obtain and use energy to run
the processes of life.
•Homeostasis – living organisms maintain a
consistent internal environment.
Characteristics of Living Organisms
• Heredity – living things
pass traits to offspring.
• Responsiveness – all
living things respond
and adjust to the
environment.
• Growth and
Development – all living
things grow and
development.
Throughout this year, we
will discuss seven themes
of biology that are based
on the seven properties of
life.
We will learn about:
•Cellular structure and
function:
•Cells are highly organized,
tiny structures with thin
coverings called membranes.
All living things are made of
one or more cells. A cell is
the smallest unit capable of
all life functions.
We will learn about:
•Reproduction:
•Reproduction is the
process by which
organisms make
more of their own
kind from one
generation to the
next.
We will learn about:
•Metabolism:
•Metabolism is the sum of all the chemical
reactions carried out in an organism. Almost
all energy used by living organisms is originally
captured from sunlight.
We will learn about:
•Homeostasis:
•Homeostasis is the
maintenance of a stable
internal conditions in spite of
changes in the external
environment. An organism
unable to balance its internal
conditions with its
environmental conditions
could become ill and die.
We will learn about:
•Heredity:
•Heredity is the passing of traits from parent to
offspring. The basic unit of heredity is called a
gene. Genes are coded in a molecule called
deoxyribonucleic acid (DNA). Genes
determine an organism’s traits. A change in
the DNA of a gene is called a mutation. Most
mutations are harmful, but some can help an
organism survive.
We will learn about:
•Evolution:
•Evolution is defined as change in the
inherited characteristics of species
over generations. A species is a
group of genetically similar
organisms that can produce fertile
offspring. Natural selection is the
process in which organisms with
favorable traits are more likely to
survive and reproduce.
We will learn about:
•Interdependence:
•The organisms in a biological community live
and interact with other organisms. Ecology is
the branch of biology that studies the
interactions of organisms with one another
and with the nonliving part of their
environment. Organisms are dependent on
each other and on their environment.