1. Biology Bio (life) ology (study of)

2. A. Characteristics of Living Things

3. 1. Cells
All living things are composed of cells

4. Cell structure and function
Cell basic unit of life
All organisms are made of and develop from cells
Some composed of only a single cell (unicellular)
Virtually identical to parent
Some composed of many cells (multicellular)
Cells are different (undergo differentiation)
Cells are small
Cells are highly organized

5. 2. Organization
Each life process that an organism performs is vital to its existence. All life processes come together to create a single orderly living system.

6. Example:
In multicellular organisms cells and groups of cells (tissues) are organized by their function
Cells  tissues
Tissues  organs
Organs  systems
Systems organism

7. 3. Reproduction All species have the ability to reproduce
Not essential to survival of individual but is essential for continuation of a species

8. Species
Donkey
Horse
A group of organisms that can interbreed and produce fertile offspring
Mule

9. 4. Growth & Development Growth is increasing in size over time.
Development is changing toward final adult form.

10. 5. Respond to Change (Responsiveness)
Respond to stimuli in the external environment.

11. 4a. Environment
An organisms surroundings, which includes the air, water, weather, temperature, and any other organisms in the area.

12. 4b. Stimulus
A condition in the environment that causes an organism to adjust.

13. 4c. Response
The reaction to a stimulus.

14. 4d. Homeostasis
homeo (same) stasis (steady state)

15. Stability and homeostasis
Regulation of internal conditions in order to adjust to external environment. Maintain very stable internal conditions
Example: temperature 37° hot-perspirecools cold-shiverwarms Other examples include: water content, chemical content, etc.

16. 4e. Energy
The ability to do work. Work is anything that causes motion. Work is required to be a living thing. Every living thing uses energy from some of the materials in food as fuel for the functions needed to keep it alive.

17. Energy continued
Almost all energy comes from the sun (directly or indirectly)
Photosynthesis is the process by which some organisms capture the energy from the sun (solar) and transform it into energy (chemical) that can be used by living things

18. Autotrophs Organisms that make their own food are called autotrophs
Phototrophs – use solar energy (photosynthesis) to get energy
Convert H2O and CO2 into sugar and O2
Chemotrophs – use different chemical processes to get energy

19. Heterotrophs
Organisms that must take in food to meet their energy needs are called heterotrophs Consume autotrophs (herbivores), other heterotrophs (carnivores) or both (omnivores) for their energy needs
Complex chemicals are broken down and reassembled into chemicals and structures needed by organisms

20. Matter, Energy and Organization
Living things are highly organized
Requires a constant supply of energy to maintain their orderly state

21. 6. Adapt & Evolve

22. Adaptation
Any structure, behavior, or internal process that enables an organism to respond to stimuli and better survive in an environment.
Ability to adapt to their environment through the process of evolution
Favorable characteristics are selected for and passed on to offspring

23. Evolution The gradual accumulation of adaptations over time.
Change over time.

24. Natural Selection Natural selection is the driving force in evolution
Organisms that have certain favorable traits are better able to successfully reproduce than organisms that lack these traits
Survival of organisms with favorable traits cause a gradual change in populations over many generations  “descent with modification”

25. Misconception: “Natural selection involves organisms ‘trying’ to adapt
Natural selection leads to adaptation, but the process doesn’t involve “trying.” Natural selection involves genetic variation and selection among variants present in a population. Either an individual has genes that are good enough to survive and reproduce, or it does not, but it can’t get the right genes by “trying.”