Themes of Biology

 

I. Science => The study of how the world works and how

things in nature happen.

A. Biology => The study of living things

1. Different fields in Biology

a. Zoology

b. Anatomy and Physiology

c. Marine Biology

d. Environmental Science

e. Ecology

 

II. Characteristics of Living Organisms

Seven themes.

 

A. Cells => All living things are made of cells, if

multicellular then they are specialized cells to carry

out specific functions.

1. Cells are the lowest level of organization that

can carry out all of the life processes.

2. Cell Theory =>

a. All organisms are composed of cells

b. All cells come from preexisting cells

 

B. Reproduction is the process by which organisms make more of their own kind from one generation to the next.

 

C. 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

1. Energy => The ability to do work

2. Every cell must burn energy to do work

a. Cells can break down chemically to make

energy

 

 

D. 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.

 

E. 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 mutations can help an organism survive.

 

 

F. Evolution is defined as change in the inherited

characteristics of species over generations. Aspeciesis a group of genetically similar organisms that can produce fertile offspring (Change over time). Natural selection is the process in which organisms with favorable traits are more likely to survive and reproduce.

 

 

G. The organisms in a biological community live and

interact with other organisms.Organisms are dependent on each other and on their environment.

 

III. Levels of Organization

A. Atoms

B. Cells

C. Tissues

D. Organs

E. Organ Systems

F. Organisms

G. Population

H. Ecosystem