1. Chapter 1 : The Science of Life pg. 4
Section 1 : The World of Biology

2. Biology- the study of life
How is biology important to a person’s daily life and to human society?

3. Knowledge of biology allows us to make informed decisions and know about our health, technology, the food we eat, pollution, diseases, and the environment.

4. Characteristics of Life
1. Organization and Cells
2. Response to Stimuli
3. Homeostasis
4. Metabolism
5. Growth and Development
6. Reproduction
7. Change Through Time

5. 1. Organization and Cells
Organization- the high degree of order within an organism’s internal and external parts and in its interactions with the living world

6. Organs- structures that carry out specialized jobs within an organ system; made of tissues
Tissues- groups of cells that have similar abilities
Cell-the smallest unit that can perform all life’s processes

7. Organelles- tiny structures that carry out functions necessary for the cell to stay alive
Examples: mitochondria & Golgi Apparatus
Biological molecules- the chemical compounds that provide physical structure and enable other cellular functions and biological molecules are made of ATOMS

8. Organization also includes:
Unicellularity-
Multicellularity-
Single-celled
More than one cell

9. 2. Response to Stimuli
An organism’s response to a stimulus (a physical or chemical change in the environment)
Examples: pupil dilation in response to bright light
What are some other examples of an organism responding to a stimulus?

10. 3. Homeostasis
Homeostasis- the maintenance of a stable level of internal conditions even though environmental conditions are constantly changing.
Examples: burning calories to stay warm
:Birds fluffing up feathers to keep warm

11. 4. Metabolism
Metabolism- the sum of all the chemical reactions that take in and transform energy and materials from the environment; getting energy from the food we eat
Or……………….
photosynthesis

12. 5. Growth and Development
*All living things grow and increase in size.
Growth in living things occurs by cell division and not accumulation of matter such as occurs in crystals
(nonliving)
Development- the process by which an organism becomes a mature adult

13. 6. Reproduction Producing offspring
*NOT essential to the survival of an individual
DNA transmits heredity information from parent to offspring

14. Why is reproduction an important characteristic of life?
Gene- a short segment of DNA that contains the instructions for a single trait of an organism
Why is reproduction an important characteristic of life?
*Reproduction is essential to the continuation of a species*

15. Types of Reproduction Asexual Sexual
One parent; produces identical offspring
Ex. bacteria
2 parents produce offspring that contain genetic material from both parents; a different individual

16. 7. Change Through Time Evolution- changes in a population over time
The ability of populations of organisms to change over time is important for survival in a changing world.
Also, it explains the diversity of life-forms found on earth today.
Evolution- changes in a population over time