Biology 11 - Introduction to Biology - PowerPoint PPT Presentation

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Biology 11 - Introduction to Biology

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Title: Biology 11 - Introduction to Biology


1
Introduction to Biology
2
Welcome to Biology
  • Biology a science, specifically the studying of
    living things
  • Modern biology is grounded in the study of
  • Cell Theory
  • Genetics (gene theory)
  • Energy
  • Homeostasis
  • Evolution

3
What makes something alive?
  • The following are characteristics of living
    things
  • Maintain homeostasis a steady internal state

4
What makes something alive?
  • Have the ability to reproduce

5
What makes something alive?
  • Have metabolism

6
What makes something alive?
  • Have some sort of cellular organization /
    function
  • Contain genetic information

7
What makes something alive?
  • The following are characteristics of living
    things
  • Maintain homeostasis a steady internal state
  • Have the ability to reproduce
  • Have some sort of cellular organization /
    function
  • Have metabolism use chemical energy to survive
  • Contain genetic information

8
What makes something alive?
  • The following are characteristics of living
    things
  • Maintain homeostasis a steady internal state
  • Have the ability to reproduce
  • Have some sort of cellular organization /
    function
  • Have metabolism use chemical energy to survive
  • Contain genetic information

9
Interesting Facts about Cells
  • The average human being is composed of around 100
    Trillion individual cells!!!
  • It would take as many as 50 cells to cover the
    area of a dot on the letter i
  • People did not always know about cells.

10
DISCOVERING CELLS
11
Microscopes
  • Cells are tiny, not discovered until the
    invention of the microscope
  • Microscopes magnify an object
  • Magnification
  • Means making objects appear larger than they are
  • Example Magnifying class

12
Magnification
13
Microscopes
  • Resolution
  • How clearly an image appears
  • High Resolution clear image, lots of detail
  • Low Resolution blurry image, less detail

14
Resolution
15
Resolution
16
Resolution
17
Resolving Power
  • The ability to distinguish between two dots or
    objects that are very close together is called
    resolving power.
  • The human eye has a certain resolving power. You
    can see the individual dots in diagrams A, B and
    C. The human eye does not have the resolving
    power to see the dots in diagram D.

18
Robert Hooke
  • Invents a single-lens microscope and observes the
    world around him (late 1600s)
  • Records observations in his book Micrographia
    (1665)

19
Hookes Mircoscope
20
Hookes Microscope
21
Hookes Drawings
More to the world than meets the eye
22
Hookes Drawings
23
Hookes Drawings
  • Long-legged spider

24
Robert Hooke
  • Discovers Cells (1665)
  • Observes bark of a cork tree
  • Observes tiny honey comb structures, which he
    calls cells
  • Problem
  • Cork bark cells are dead
  • Thought only plants had cells

25
Cork Bark Cells
26
Anton van Leuwenhoek
  • Makes observations at same time as Hooke
  • Improves the Microscope
  • Grinds the lens of the microscope to the size of
    a pin head
  • Improves magnification to 350x

27
AVLs microscope
28
Anton van Leuwenhoek
  • Observes (1) rain pond water, and (2) blood
  • Animacules
  • Observed living cells in water
  • These were bacteria cells
  • Blood Cells
  • Observes different types of cells in blood

29
Life in Water
30
Life in Water
31
Cells in Human Blood
32
Spontaneous Generation
  • Few discoveries about cells from 1650 to 1850.
    But why?
  • People believe in Spontaneous Generation
  • The belief that life simply starts
  • Maggots come from rotting meat
  • Mice come from dirty clothes and corn



33
MODERN CELL THEORY
34
Spontaneous Generation Disproved
  • Francesco Redi
  • Italian physician poet
  • One of the first scientists to disprove
    spontaneous generation
  • Performs famous experiment in 1668

35
Spontaneous Generation Disproved
36
Cell Theory (classical)
  • 3 major laws
  • All organisms are made of one or more cells.
    (Schleiden Schwann)(1838-39)
  • The cell is the basic unit of life in all living
    things. (Schleiden Schwann)(1838-39)
  • All cells come from other (preexisting) cells.
    (Virchow)(1858)

37
Cell Theory (modern)
  • Modern cell theory adds 4 more statements
  • The cell contains hereditary information(DNA)
    which is passed on from cell to cell during cell
    division.
  • All cells are basically the same in chemical
    composition and metabolic activities.
  • All basic chemical physiological functions take
    place in the cell
  • Cell activity depends on the activities of
    structures within the cell (organelles, nucleus,
    plasma membrane

38
Cell Specialization
  • Some cells are part of a larger organism
  • These cells must become specialized and perform
    specific jobs
  • Cell Specialization
  • When cells perform a specific function as part of
    a larger organism
  • To perform this job, cells often become
    specialized (look work differently)

39
Examples of Cells
Amoeba Proteus
Plant Stem
Bacteria
Red Blood Cell
Nerve Cell
40
Compound Light Microscope
  • Has 2 sets of lenses that magnify an image.
  • Each objective lens has a different magnification
    power.
  • Low power 4x objective
  • Med power 10x objective
  • High power 40x objective
  • Multiply the objective by eyepiece for total
    magnification.
  • Example High Power 40 x 10 400 x
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