INTRODUCTION TO BIOLOGY

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INTRODUCTION TO BIOLOGY
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How does life begin?

• There were 2 theories
• Spontaneous generation
• Biogenesis

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Spontaneous Generation

• Process by which life begins when ethers enter
  nonliving things
• Francesco Redi conducted an experiment to
  disprove this theory

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Redis Experiment

• During Redis time maggots were thought to come
  from rotting meat
• Redi placed meat in an open jar and maggots
  appeared on the meat
• Redi placed meat in a closed jar and no maggots
  appeared
• Critics of Redi suggested that the ethers could
  not enter the container which is why the maggots
  did not appear

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Redis Revised Experiment

• Redi placed meat in a jar covered with a mesh
  cloth to allow ethers to enter but nothing else
• Maggots did not appear on the meat

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Biogenesis

• Principle that life comes only from life
• After Francesco Redi disproved the theory of
  spontaneous generation, Louis Pasteur conducted
  an experiment to prove biogenesis

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Pasteurs Experiment

• Broth is placed in a flask with a curved neck to
  prevent dust from entering the broth
• The broth is heated and after one year, the broth
  was still free of bacteria
• The curved neck is broken off so that dust can
  now enter the flask
• After one day, the broth was cloudy and filled
  with bacteria

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Characteristics of Life

• Organization living things are organized the
  basic unit of organization is the cell
• Energy living things use sound, light and
  chemical energy all living things take in energy
  from the environment and use it for their life
  processes
• Growth and Development
• Growth is an increase in size
• Development is a change in shape or form

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Characteristics of Life (cont.)

• Reproduction process by which new living things
  are formed
• Response and Adaptation
• Response includes migration, movement, color
  changes, etc.
• Adaptation is a way for an entire population of
  organisms to respond to long-term changes in
  their surroundings these are passed on from
  generation to generation

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Levels of Organization

• Atom
• Molecule
• Cell
• Tissue
• Organ
• Organ System
• Organism
• Population
• Community
• Ecosystem
• Biosphere

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Population, Community, Ecosystem Biosphere

• Population group of organisms of the same
  species that live together in a particular
  location
• Community include all organism populations in a
  particular location
• Ecosystem all the communities and the non-living
  parts in a particular location
• Biosphere thin layer of air, land and water on
  the surface of the earth