CHAPTER 1 – THE NATURE OF
LIFE
THE NATURE OF LIFE
THE NATURE OF LIFE
• MARS VS EARTH (WHAT’S THE BIG DEAL?!?)
THE NATURE OF LIFE
• BIOLOGY
– THE STUDY OF LIVING THINGS
THE NATURE OF LIFE
• WHAT DOES IT MEAN TO BE ALIVE??
– THERE IS NO EASY ANSWER/DEFINITION TO THIS
QUESTION…SO WHAT CAN WE DO TO FIGURE OUT
IF SOMETHING IS “ALIVE”??
THE NATURE OF LIFE
• WE DEFINE SOMETHING AS BEING ALIVE (AN ORGANISM)
IF IT HAS THE FOLLOWING CHARACTERISTICS:
– LIVING THINGS ARE HIGHLY ORGANIZED AND CONTAIN MANY
COMPLEX CHEMICAL SUBSTANCES
– LIVING THINGS ARE MADE UP OF ONE OR MORE CELLS
– LIVING THINGS USE ENERGY
– LIVING THINGS HAVE A DEFINITE FORM AND A LIMITED SIZE
– LIVING THINGS HAVE A LIMITED LIFE SPAN
– LIVING THINGS GROW
– LIVING THINGS RESPOND TO CHANGES IN THE ENVIRONMENT
– LIVING THINGS ARE ARE ABLE TO REPRODUCE
– GROUPS OF LIVING THINGS CHANGE OVER TIME (EVOLUTION)
THE NATURE OF LIFE
• SAY HELLO TO THE EBOLA VIRUS…
– IS IT ALIVE??
– DOES IT MEET
ALL THE
CRITERIA
MENTIONED
PREVIOUSLY??
THE NATURE OF LIFE
• WE DEFINE SOMETHING AS BEING ALIVE (AN ORGANISM)
IF IT HAS THE FOLLOWING CHARACTERISTICS:
– LIVING THINGS ARE HIGHLY ORGANIZED AND CONTAIN MANY
COMPLEX CHEMICAL SUBSTANCES - CHECK
– LIVING THINGS ARE MADE UP OF ONE OR MORE CELLS - CHECK
– LIVING THINGS USE ENERGY - CHECK
– LIVING THINGS HAVE A DEFINITE FORM AND A LIMITED SIZE CHECK
– LIVING THINGS HAVE A LIMITED LIFE SPAN - CHECK
– LIVING THINGS GROW - CHECK
– LIVING THINGS RESPOND TO CHANGES IN THE ENVIRONMENT CHECK
– LIVING THINGS ARE ARE ABLE TO REPRODUCE – FAIL!!
THE NATURE OF LIFE
• NON-LIVING THINGS MAY EXHIBIT SOME OF
THE CHARACTERISTICS LISTED, BUT UNLESS
ALL OF THEM ARE PRESENT…IT IS
CONSIDERED A NONLIVING THING
THE NATURE OF LIFE
• ANOTHER WAY TO DETERMINE IF SOMETHING
IS LIVING IS IF IT PERFORMS ALL OF THE…
•LIFE PROCESSES
THE NATURE OF LIFE
• LIFE PROCESSES =
H.N.T.R.S.G.E.R.M.R.
(“HUNTERS GERMER”)
THE NATURE OF LIFE
• H = HOMEOSTASIS
• G = GROWTH
• N = NUTRITION
• E = EXCRETION
• T = TRANSPORT
• R = REGULATION
• R = RESPIRATION
• M = METABOLISM
• S = SYNTHESIS
• R = REPRODUCTION
THE NATURE OF LIFE
• HOMEOSTASIS
– MAINTAINING A
STABLE INTERNAL
ENVIRONMENT
– “FEEDBACK”
MECHANISMS
THE NATURE OF LIFE
• NUTRITION
– TAKING MATERIALS FROM THE EXTERNAL
ENVIRONMENT AND TURNING THEM INTO FORMS
YOU CAN USE
– AUTOTROPHIC
VS.
HETEROTROPHIC
– INGESTION
VS.
DIGESTION
VS.
EGESTION
THE NATURE OF LIFE
• TRANSPORT
– THE PROCESS BY WHICH
SUBSTANCES ENTER AND
LEAVE CELLS AND BECOME
DISTRIBUTED WITHIN THE
CELLS
– *CIRCULATORY SYSTEM*
• SPECIALIZED SYSTEM TO ALLOW
FOR TRANSPORT
THE NATURE OF LIFE
• RESPIRATION
– BREATHING
VS.
CELLULAR
RESPIRATION
– AEROBIC
VS.
ANAEROBIC
THE NATURE OF LIFE
• SYNTHESIS
– COMBINING
SIMPLE SUBSTANCES
TO FORM LARGER,
MORE COMPLEX
SUBSTANCES
THE NATURE OF LIFE
• GROWTH
– PROCESS
BY WHICH
ORGANISMS
INCREASE IN SIZE
(EITHER # OF CELLS,
OR SIZE OF CELL)
THE NATURE OF LIFE
• EXCRETION
– THE REMOVAL OF
METABOLIC WASTES
THE NATURE OF LIFE
• REGULATION
– ALL THE
ACTIVITIES
THAT HELP
AN ORGANISM
MAINTAIN
HOMEOSTASIS
– A.K.A
“RESPONSE”
THE NATURE OF LIFE
• METABOLISM
– ALL THE
CHEMICAL
REACTIONS
(RxNS) THAT
OCCUR IN
THE BODY
THE NATURE OF LIFE
• REPRODUCTION
– THE PROCESS
BY WHICH
LIVING THINGS
PRODUCE NEW
ORGANISMS
OF THEIR
OWN KIND
– ASEXUAL
VS.
SEXUAL
– *ONLY PROCESS THAT IS
NOT NECESSARY FOR
INDIVIDUAL*
THE NATURE OF LIFE
• ALWAYS REMEMBER…
• H.N.T.R.S.G.E.R.M.R
THE NATURE OF LIFE
• NEXT TIME…
WE TALK ABOUT WHY
I, AND YOU,
LOVE SCIENCE
• LEARN TO THINK,
AND ACT, LIKE A
SCIENTIST