CHAPTER 1 : THE STUDY OF LIFE SECTION 1 : Introduction to Biology

The Science of Life Biology : is the study of living things. In biology, you study the origins and history of life and once-living things, the structures of living things, how living things interact with one another, and how living things function. Biologists study the following: Diversity of life: study how living organisms interact with their environment. Research diseases, study how diseases work and how to prevent them. Biologists develop new vaccines and treatments. Develop technologies: discover tools that are used to improve lives through biomedical engineering and biotechnology.

Cont’d Improve Agriculture research: research agricultural issues for food production, study ways to genetically engineer the growth off plants. Preserve the environment: study ways to keep the environment safe, study animal and plant species and the affect human behavior has had on them.

THE CHARACTRISTICS OF LIFE How do biologists decide if something is alive? Over time, biologists have learned that living things have certain characteristics. An organism is anything that has or once had all of the following characteristics: Made of one or more cell Displays organization Grows and develops Reproduces Responds to stimuli Maintains hemostasis Adaptations evolves over time

MADE OF ONE OR MORE CELL All organisms are made up of one or more cell. The cell is the basic unit of life. Some organisms are unicellular or multi-cellular.

DISPLAYS ORGANIZATION Living things have to be arranged in an orderly way. In unicellular organisms, one cell can be responsible for all the life functions. In multi-cellular organisms the order is an follows: Cells tissue organs organ systems organism.

GROWS AND DEVERLOPS Growth is an important characteristic for a living thing. Most organisms begin as one cell. Growth can add mass to an organism by the formation of new, additional cells, and structures. Development: The process of natural changes that take place during the life of an organism.

REPRODUCES Reproduction: the production of offspring. If a species wants to continue to exist, then it must reproduces. Species: a group of organisms that can breed with one another and produce fertile offspring. If reproduction does not take place for a particular species, then that species will eventually becomes extinct ( no longer exist).

RESPONDS TO STIMULI A stimulus is a anything that is a part of an organisms internal and external environment that causes some type of reaction. Any reaction is a stimulus is called a response. An organisms ability to respond to stimuli is extremely important because it is critical for its safety and survival. Ex: Sharks respond to the smell of blood in the ocean. Plants respond to lights if placed near the window. Humans respond to any signs of immediate danger.

REQUIRES ENERGY Living things need energy for their life function. Living things get energy from food like plants and animals. Plants get their energy from the sun. Cells can transform energy into chemical compounds. Some organisms consume other organisms if they cannot make their own food.

MAINTAINS HOMEOSTASIS Homeostasis – regulation of an organism’s internal conditions to maintain life. If something Happens to or within an organism that effect’s its internal state, then there are processes that begin to bring the organism back to homeostasis. Example: Athletes competing at higher altitudes, switching between extremely hot and cold temperatures.

ADAPTATIONS EVOLVE OVER TIME Over a long period of time, organisms begin to inherit certain characteristics to allow them to survive. Adaptation: it is any inherited characteristics that results from changes to a species over time. Example: Cactus plant

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