Biology is the study of life. All living organisms share certain characteristics and life functions including nutrition, transport, respiration, excretion, synthesis, regulation, growth, and reproduction. These life functions allow organisms to sustain life through metabolic activities and maintain homeostasis.

1. What is Biology ?
Biology is the study
of life
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2. SO… WHAT IS LIFE
 Life is defined by a list of characteristics
organisms must possess to be considered
living.
 All living organisms contain the same life
functions although their means of
achieving them may be different
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3. Life Functions
1. Nutrition - activities of an organism, used to obtain materials
from the environment and process them for their use.
Two types of nutrition
Autotrophic Heterotrophic
Materials CO2 H 2O organic food
Light energy
Process Photosynthesis Ingest, digest, egestion
Organism Plants and algae other organisms
2. Transport - involves the absorption and
distribution of materials within an organism.
3. Respiration - includes the chemical process by
which an organism obtains energy (ATP) from its
food (Glucose). 3

4. Life Functions
4. Excretion - the removal of wastes produced
by cells during metabolic activities.
5. Synthesis - includes the chemical activities by
which an organism builds larger molecules from
smaller ones. (to Make)
6. Regulation - involves the control and
coordination of various activities in an organism.
(Nervous system and Endocrine system play a
role)
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5. Life Functions
 7. Growth - increases in cell size and/or
cell numbers.
 8. Reproduction - production of new
individuals. A species survival depends on
reproduction. An individual’s life does not.
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6. II. Important Terms
1. Metabolism - refers to all the life functions
needed to sustain life. Does not include
reproduction
2. Homeostasis - the maintenance of a stable
internal environment. (Regulation helps to achieve
Homeostasis)
• Your body systems are constantly adjusting to
maintain homeostasis.
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7. MR STRANGER
 M=Metabolism
 R= Respiration
 S= Synthesis
 T= Transport
 R= Regulation
 A= Ambulation (Locomotion)
 N=Nutrition
 G=Growth
 E=Excretion
 R= Reproduction 7