Understanding%20Animal%20Life%20Span%20Unit%203,%20Lesson%202

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Understanding Animal Life SpanUnit 3, Lesson 2
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Life Span

• Live span is the period of life for an organism.
  It is the length of time between birth and death.
• Based on the average amount of time an organism
  lives
• Humans 75 years in U.S.
• Cattle 12-15 years

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Living Condition

• Living condition is the ability of an organism
  to carry out life processes, needed for
  protoplasm to function.
• 7 Processes needed to remain alive
• Getting and using food
• Movement
• Circulation
• Respiration
• Growth and repair
• Secretion
• Sensation
• Some have 2 more processes
• Reproduction
• Lactation

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The 5 Stages of Life

• All organisms have a definite sequence of stages
  of life
• A. Stages of Life developmental periods with
  common characteristics that represent various
  conditions of the organism.
• B. These stages are recognized in most animals
  lives.

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Stage 1 Beginning

1. The start of an organisms life.
2. With mammals, begins with conception or birth,
   depending on calculation.
3. Age begins with day of birth.
4. Living organism starts forming at conception.

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Stage 2 Growth

1. The time following the beginning
2. Organism is rapidly increasing in size and
   developing skills.

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Stage 3 Maturity

1. The state when organism is fully developed.
2. Carries out functions of adults
3. No longer increases much in size
4. Have reached reproductive potential

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Stage 4 Decline

1. The stage of life that follows maturity
2. Organism has lived past maturity and begins to
   lose the ability to maintain itself
3. Cells are no longer repaired and replaced
4. Associated with aging

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Stage 5 Death

1. Protoplasm in the cells of the organism cease to
   function.
2. Chemical activity in the cells stops
3. Organism is no longer alive.

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C. An example The Horse

1. Stage 1 Conception
2. Stage 2 During the first 2-3 years of life
3. Stage 3 10-12 years following growth
4. Stage 4 Horse starts losing teeth, bone
   problems, deterioration
5. Stage 5 Death follows when horse stops breathing