1. What Does it Mean to Be Alive?
What Are The Characteristics of Life?

2. Exploring LIFE Biology – The study of Life
What does it mean to be ALIVE?
How do you know if something is ALIVE?

3. Is Fire ALIVE?

4. Characteristics of Life!
All living things share basic properties  Eight Characteristics of Life
C  Composed of cells (+1)
H  Homeostasis
A  Adaptation
R  Reproduce
R  Respond to the environment
G  Growth & Development
E  Energy (metabolism)
D  DNA /RNA (genetic material)

5. All Living Things are Made Up of Cells
Living organisms consist of organic (carbon-containing) molecules  organized to form cells
Cells  Life’s basic units of structure and function

6. Unicellular Organisms
Entire organism is made up of one single cell
Bacteria and protists

7. Multicellular Organisms
The organism is made up of many cells
Cells have specialized functions within the organism

8. All Organisms Maintain Homeostasis
Homeostasis = ability of an organism to maintain relatively constant, stable state of internal conditions
EXAMPLES:
Body temperature
Blood volume
pH balance
Water balance
All organ systems contribute to homeostasis

9. All Living Things Adapt to Their
Environment Through Evolution
Adaptation
A trait (or process) that enables organisms to become better suited to their environment
Species obtain adaptations through evolution, which occurs over great periods of time

10. Evolution Gradual change in a species over time
Species differ greatly in their adaptations to the many distinct environments on Earth
Both the unity and diversity of organisms can be explained by the mechanisms of evolution and natural selection….more on that later 

11. An Example of Adaptation
Desert plants have succulent waxy leaves and stems to store water and reduce water loss

12. All Living Things Reproduce
Reproduction is the process of producing new organisms. Two types:
Asexual Reproduction
A single parent organism reproduces by itself
Ex: binary fission in bacteria

13. Sexual Reproduction
Two different parent organisms contribute genetic information
Involves the combination of male and female sex cells

14. Respond to the Environment
Living things respond to the environment by reacting to a stimulus (a thing or event that produces a specific reaction)

15. All Living Things Respond to Their Environment
Example: A plant’s leaves and stems grow toward light
Organisms react to stimuli:
Light
Temperature
Odor
Sound
Gravity
Heat
Water
Pressure

16. ALL ORGANISMS GROW & DEVELOP
Growth & Development
ALL ORGANISMS GROW & DEVELOP

17. All Living Things Grow
Growth means to get bigger in size

18. All Living Things Develop
Development involves a change in the physical form or physiological make-up of an organism

19. ENERGY:
All living organisms obtain & use energy for all body processes: growth and development, damage repair, , transport, and reproduction

20. Energy: Two types of Living Organisms
1. PRODUCERS:
- Plants, algae, and other photosynthetic organisms that
produce their own “food” for energy (from CO2, H2O, & the sun)
- Entire ecosystems depend on producers
2. CONSUMERS:
- Organisms that obtain nutrients and energy from consuming the food made by producers

21. Metabolism All chemical reactions occurring within an organism
Anabolism + Catabolism = Metabolism

22. Anabolism
Process of building up complex substances from simpler substances
Building up cells and cellular components
Photosynthesis

23. Catabolism
Process of breaking down complex substances into simpler substances to release energy
Digestion
Cellular Respiration

24. All Organisms Pass Along Hereditary Traits
Genes carry hereditary information
Genes are composed of DNA
Heredity is the reason offspring resemble their parents
Mutations change DNA code and can be passed from generation to generation

25. Characteristics of Life - RECAP
C  Composed of cells (+1)
H  Homeostasis
A  Adaptation
R  Reproduce
R  Respond to the environment
G  Growth & Development
E  Energy (metabolism)
D  DNA /RNA (genetic material)

26. Organisms
Viruses
Metabolism
Do not metabolize
Grow and Develop
No Growth and Development
Sexual or Asexual Reproduction
Must use the machinery of cells to reproduce
Composed of cells
DNA or RNA and a protein coat – no cells
Maintains Homeostasis
Does not maintain Homeostasis

27. STRUCTURE OF A VIRUS
CAPSID (protein coat)
DNA or RNA

30. How is life classified? Taxonomy = biological classification
binomial nomenclature
Two-word “scientific” name (Genus & species)

31. Benefits of Classifying
Accurately & uniformly names organisms
Prevents misnomers such as “starfish” & “jellyfish” that aren't really fish
Uses same language (Latin or some Greek) for all names
Sea”horse”??

32. Prokaryotes – The first Cells
Cells that lack a nucleus or membrane-bound organelles
Includes bacteria
Simplest type of cell
Single, circular chromosome
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Prokaryotes
Nucleoid region (center) contains the DNA
Surrounded by cell membrane & cell wall (peptidoglycan)
Contain ribosomes (no membrane) in their cytoplasm to make proteins
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Eukaryotes
Cells that HAVE a nucleus and membrane-bound organelles
Includes protists, fungi, plants, and animals
More complex type of cells
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Eukaryotic Cell
Contain 3 basic cell structures:
Nucleus
Cell Membrane
Cytoplasm with organelles
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