HOW TO DEFINE LIFE

Is Ebola a living thing? Most people have heard of Ebola – a deadly VIRUS that is affecting people in parts of Africa. Viruses: Have DNA..... but no cellular structure Can reproduce.....but only with a host Use energy.... but this comes from the host cell’s machinery So....is the Ebola virus a living thing? What do you think?

How do you know something is alive?  Biology means the study of (-ology) all life (bio-) and includes many branches

How do you know something is alive?  Biologists organize living things into kingdoms. There are currently six kingdoms.

How do you know something is alive? KingdomExample Archaebacteria Extremophile bacteria Eubacteria Typical bacteria Protista Seaweed, Amoeba, Slime Mold Fungi Yeast, Mushrooms Plantae Moss, Fern, Holly, Oak Tree Animalia Worms, Fish, Birds, Frogs, Humans

CHARACTERISTICS OF LIFE & LIFE PROCESSES  ORGANIZATION  The level of complexity  All living things need six essential elements: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur (CHNOPS)  All living things are made cells  One-celled organism - unicellular  Many-celled organism - multicellular

CHARACTERISTICS OF LIFE & LIFE PROCESSES  ENERGY USE  Organisms need energy constantly to build molecules (synthesis) and cell and to break down (digest) substances (such as breaking down food for nutrition)

Fill It In …  Synthesis means ….  Visual:

CHARACTERISTICS OF LIFE & LIFE PROCESSES  ENERGY USE  Organisms must transport nutrients to be used in cellular respiration to produce energy

CHARACTERISTICS OF LIFE & LIFE PROCESSES  ENERGY USE  An organism’s chemical reactions are called its metabolism

CHARACTERISTICS OF LIFE & LIFE PROCESSES  REPRODUCTION  An organism must replace themselves so the entire species will survive

CHARACTERISTICS OF LIFE & LIFE PROCESSES  REPRODUCTION  May be asexual (only one individual contributes genetic material) or sexual (two individuals contribute genes)

CHARACTERISTICS OF LIFE & LIFE PROCESSES  GROWTH & DEVELOPMENT  Growth - to increase in size. Increases the number of cells of a multicellular organism  Development - change that takes place in structure and function of an organism during its life cycle. Example: embryo becomes a fetus

CHARACTERISTICS OF LIFE & LIFE PROCESSES  RESPOND TO STIMULI  A quick, non-permanent change  Stimulus - anything that causes an organism to react Example: a loud noise (stimulus) causes your dog to run under the bed (response)

CHARACTERISTICS OF LIFE & LIFE PROCESSES  ADJUST TO ENVIRONMENT  Homeostasis - the regulation of an organism’s internal environment to maintain conditions for life  Ex: Getting rid of wastes by excretion

CHARACTERISTICS OF LIFE & LIFE PROCESSES  ADJUST TO ENVIRONMENT  An adaptation is an inherited structure, behavior, or internal process that enables organisms to better survive an environment  Ex: Gills on a fish

Fill It In …  Life Processes: (things you do)  S-  T-  E-  R-  N-  G-  R-

Fill It In …  Life Processes: (things you do)  S- synthesis  T- transport  E- excretion  R- regulation  N- nutrition  G- growth & development  R- reproduce  R- respond to stimuli

Something extra …  Characteristics of Life: (things you have)  C-  H-  R-  E-  G-  L-  E-  R-

Something extra …  Characteristics of Life: (things you have)  C- cells  H- homeostasis  R- reproduction  E- energy  G- genetic material (DNA)  L- levels of organization  E- evolve  R- respiration

Check Yourself!  What is the basic unit of life?  A group of cells that perform a similar function are known as a ___________.  What are two reasons an organism needs energy?  Label the following an an adaptation or a response to a stimulus  The hollow bones of a bird __________________  Jerking your hand away from a hot stove ___________________

Check Yourself!  What is the basic unit of life? CELL  A group of cells that perform a similar function are known as a ___________.  What are two reasons an organism needs energy?  Label the following an an adaptation or a response to a stimulus  The hollow bones of a bird __________________  Jerking your hand away from a hot stove ___________________

Check Yourself!  What is the basic unit of life? CELL  A group of cells that perform a similar function are known as a _TISSUE_.  What are two reasons an organism needs energy?  Label the following an an adaptation or a response to a stimulus  The hollow bones of a bird __________________  Jerking your hand away from a hot stove ___________________

Check Yourself!  What is the basic unit of life? CELL  A group of cells that perform a similar function are known as a _TISSUE_.  What are two reasons an organism needs energy? SYTHESIS, DIGESTION, TRANSPORT, METABOLISM  Label the following an an adaptation or a response to a stimulus  The hollow bones of a bird __________________  Jerking your hand away from a hot stove ___________________

Check Yourself!  What is the basic unit of life? CELL  A group of cells that perform a similar function are known as a _TISSUE_.  What are two reasons an organism needs energy? SYTHESIS, DIGESTION, TRANSPORT, METABOLISM  Label the following an an adaptation or a response to a stimulus  The hollow bones of a bird ADAPTATION _  Jerking your hand away from a hot stove ___________________

Check Yourself!  What is the basic unit of life? CELL  A group of cells that perform a similar function are known as a _TISSUE_.  What are two reasons an organism needs energy? SYTHESIS, DIGESTION, TRANSPORT, METABOLISM  Label the following an an adaptation or a response to a stimulus  The hollow bones of a bird ADAPTATION _  Jerking your hand away from a hot stove _RESPONSE TO STIMULUS__