1. The Characteristics of Life

2. The Characteristics of Life
History:
Spontaneous Generation or Abiogenesis-
1st proposed by Aristotle
held that complex, living organisms are generated by decaying organic substances,
e.g. that mice spontaneously appear in stored grain or maggots spontaneously appear in meat.

3. The Characteristics of Life
History:
Was widely believed until the 19th century.
Several scientists performed experiments that disproved spontaneous generation
Francisco Redi
Lazzaro Spallanzani
Louis Pasteur

4. Redi’s Experiment
Francisco Redi
1668

5. Spallanzani’s Experiment
Lazzaro Spallanzani
1746

6. Pasteur’s Experiment
Louis Pasteur
1859

7. The Characteristics of Life
History:
Biogenesis- is the process of life forms producing other life forms
e.g. a spider lays eggs, which form into spiders.
The term is also used for the assertion that life can only be passed on by living things.

8. The Characteristics of Life
How can you tell if something is alive?

9. The Characteristics of Life
Biologists have devised a list of 5 characteristics that define life.
Something can be considered alive ONLY if it displays ALL 5 of the characteristics.

10. The Characteristics of Life
Anything that possesses all 5 of the characteristics of life is called an organism.

11. The 5 characteristics of life are:
Cellular Organization celltissueorgansystemorganism
2. Growth & Development
3. Reproduction
4. Adaptation to environment – response to a stimulus
5. Maintenance of Homeostasis

12. The Characteristics of Life
Organization:
All living organisms have an organized structure
Ex. -Cells form tissues
-Tissues form organs
-Organs form organ systems

13. The Characteristics of Life
Growth & Development:
All living organisms grow and develop during their life spans.

14. The Characteristics of Life
Growth: an increase in the size of an organism due to an increase in the size and number of cells
Development: all of the changes that take place throughout the life span of an organism

15. The Characteristics of Life
Reproduction:
All living organisms are able to produce live offspring.

16. The Characteristics of Life
Adaptation to environment:
All living organisms are able to adapt to their surroundings.
They are able to react, or respond to an environmental condition, or stimulus.

17. The Characteristics of Life
Maintenance of Homeostasis:
All living organisms are able to maintain a relatively constant internal environment.
Homeostasis: The regulation of an organism’s internal environment to maintain conditions suitable for life.

18. The Characteristics of Life
Are bacteria alive?
How about viruses?

19. Additional Characteristics
6. Require energy 7. Change over time or Evolve 8. Contain DNA

20. All living things require Energy
AUTOTROPH: produce own food HETEROTROPH: must consume food

21. All living things change over time
adapt to long-range changes in environment to better survive in environment
these changes take place over a long period of time & involve the entire species

22. All living things contain DNA
inheritance of traits is carried on DNA
Living things are base on the genetic code

23. Living or Not??

24. Living or Not??

25. Living or Not??

26. Living or Not??

27. Living or Not??

28. Living or Not??

29. Living or Not??

30. Living or Not??

31. You eat a hamburger for lunch.
A. Adapt D. genetic code G. Respond to stimulus B. Made of cells E. Grow and develop H. Homeostasis C. Reproduce F. Use/need energy
You eat a hamburger for lunch.
A baby gains 3 pounds in one week and begins to recognize voices.
A polar bear has white fur to blend in with the snow.
Your start to cry whenever you get a shot at the doctor’s office.
You begin to shiver because it is cold outside.
Red and white particles make up part of your blood.
A chick breaks out of an egg.