Biology The Study of Life

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Biology The Study of Life

• Chapter 1

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Why study Biology?

• What is the most direct effect of Biology on your
  life?
• Medicine

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Biological knowledge

• Biological knowledge is used to help cure genetic
  disorders.
• Genetic engineering has been trying to transfer
  normal genes to replace defective copies of that
  gene.
• Ex. of a genetic disorder - Cystic fibrosis is
  caused by 1 faulty gene. Individuals build up a
  thick mucus coating in their lungs and have
  difficulty breathing.

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Biological knowledge is used to fight disease.

• At the beginning of the 20th century the leading
  causes of death were-
• Tuberculosis
• Pneumonia
• Influenza The influenza epidemic of 1918-1919
  killed 22 million people in 18 months.

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Spanish Flu
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Leading causes of death at the present time.

• Aids
• Malaria kills 1 million people a year
• Cancer

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Malaria
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Are scientists people who know all the answers?

• In our enthusiasm for telling you all that
  Biology has discovered, do not let us convince
  you that all is known, many questions are still
  unanswered. More important, many good questions
  have not yet been asked. Perhaps you may ask one
  of them.
• Helena Curtis

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Sir Isaac Newton

• Sir Isaac Newton in a letter written to Robert
  Hook said
• If I have seen further than you. It is by
  standing on the shoulders of giants.

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Introduction

• Biology is the study of all living things and how
  they interact with each other their environment.

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Characteristics of Living Organisms

• 1. Cell structure function
• 2. Reproduction Inheritance
• 3. Stability Homeostasis
• 4. Evolution
• 5. Interdependence of Organisms
• 6. Matter, Energy Organization

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Cell Structure Function

• Cell is the basic unit of structure function
• Cells are small but highly organized- contain
  organelles that carry out the jobs of a cell.
• All cells are surrounded by a cell membrane,
  contain cytoplasm, have DNA

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Stability Homeostasis

• All organisms maintain stable internal conditions
  such as body temperature water content.
• Stable level of internal conditions is called
  homeostasis.

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Reproduction Inheritance

• All organisms reproduce new organisms by
  transmitting hereditary material to their
  offspring.
• DNA (Deoxyribonucleic acid) is a large molecule
  containing the hereditary material of the cell.

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Reproduction Inheritance

• DNA of a cell contains all of the genes
  (instructions) it will ever need.
• All body cells have a complete set of DNA
  (genome), but different types of cells use
  certain genes from the set.
• Ex Muscle cells have the genes to make
  thyroxine, but they dont use these genes.

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Evolution

• Populations of organisms change over time
  Theory of Evolution
• Natural selection or survival of the fittest is
  the process that drives evolution
• Driven by competition for resources such as food,
  habitat, mates
• Ex Great apes polar bears will be extinct by
  2050 mainly due to loss of habitat
• The survival of organism with favorable traits
  causes a gradual change in populations of
  organism over many generations.

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Interdependence of Organisms

• Ecology is the study of the interaction of
  organisms with each other their environment.
• Sunlight is the ultimate energy for all
  organisms.
• Energy from the sun is passed from one organism
  to another producers (plants) to herbivore
  (plant eater) to carnivore (meat eater) to
  decomposers (break down dead organisms).

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Interdependence of Organisms

• Human interference is the main cause for
  endangerment extinction.
• Pollution of land, air, water
• Clear-cutting rain forests
• Diverting rivers lakes
• Draining wetlands (Everglades)
• Global Warming
• Extinction of any species upsets the balance of
  nature.

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Matter, Energy Organization

• Organisms are highly organized, maintain internal
  order, require a constant energy supply.
• Plants unicellular organisms with chlorophyll
  capture sunlight through photosynthesis store
  it in food to be used by other organisms.
• Autotrophs or producers use sunlight, water,
  carbon dioxide to make glucose (energy rich
  sugar) oxygen photosynthesis
• Heterotrophs (consumers) feed on producers or
  other consumers to get energy release carbon
  dioxide.