Introduction to Biology :Introduction to Biology 1 M.Bregar (Dante C.S.S.)


Welcome to Biology :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 M.Bregar (Dante C.S.S.) 2


What makes something alive? :What makes something alive? The following are characteristics of living things Maintain homeostasis – a steady internal state 3 M.Bregar (Dante C.S.S.)


What makes something alive? :What makes something alive? Have the ability to reproduce 4 M.Bregar (Dante C.S.S.)


What makes something alive? :What makes something alive? Have metabolism 5 M.Bregar (Dante C.S.S.)


What makes something alive? :What makes something alive? Have some sort of cellular organization / function Contain genetic information 6 M.Bregar (Dante C.S.S.)


What makes something alive? :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 7 M.Bregar (Dante C.S.S.)


What makes something alive? :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 M.Bregar (Dante C.S.S.)


Interesting Facts about Cells :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. 9 M.Bregar (Dante C.S.S.)


DISCOVERING CELLS :DISCOVERING CELLS 10 M.Bregar (Dante C.S.S.)


Microscopes :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 11 M.Bregar (Dante C.S.S.)


Magnification :Magnification 12 M.Bregar (Dante C.S.S.)


Microscopes :Microscopes Resolution How clearly an image appears High Resolution = clear image, lots of detail Low Resolution = blurry image, less detail 13 M.Bregar (Dante C.S.S.)


Resolution :Resolution 14 M.Bregar (Dante C.S.S.)


Resolution :Resolution 15 M.Bregar (Dante C.S.S.)


Resolution :Resolution 16 M.Bregar (Dante C.S.S.)


Resolving Power :Resolving Power M.Bregar (Dante C.S.S.) 17 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.


Robert Hooke :Robert Hooke Invents a single-lens microscope and observes the world around him (late 1600’s) Records observations in his book – Micrographia (1665) 18 M.Bregar (Dante C.S.S.)


Hooke’s Mircoscope :Hooke’s Mircoscope 19 M.Bregar (Dante C.S.S.)


Hooke’s Microscope :Hooke’s Microscope 20 M.Bregar (Dante C.S.S.)


Hooke’s Drawings :Hooke’s Drawings “More to the world than meets the eye” 21 M.Bregar (Dante C.S.S.)


Hooke’s Drawings :Hooke’s Drawings 22 M.Bregar (Dante C.S.S.)


Hooke’s Drawings :Hooke’s Drawings Long-legged spider 23 M.Bregar (Dante C.S.S.)


Robert Hooke :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 24 M.Bregar (Dante C.S.S.)


Cork Bark – Cells :Cork Bark – Cells 25 M.Bregar (Dante C.S.S.)


Anton van Leuwenhoek :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 26 M.Bregar (Dante C.S.S.)


AVL’s microscope :AVL’s microscope 27 M.Bregar (Dante C.S.S.)


Anton van Leuwenhoek :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 28 M.Bregar (Dante C.S.S.)


Life in Water :Life in Water 29 M.Bregar (Dante C.S.S.)


Life in Water :Life in Water 30 M.Bregar (Dante C.S.S.)


Cells in Human Blood :Cells in Human Blood 31 M.Bregar (Dante C.S.S.)


Spontaneous Generation :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 + = 32 M.Bregar (Dante C.S.S.)


MODERN CELL THEORY :MODERN CELL THEORY 33 M.Bregar (Dante C.S.S.)


Spontaneous Generation Disproved :Spontaneous Generation Disproved Francesco Redi Italian physician & poet One of the first scientists to disprove spontaneous generation Performs famous experiment in 1668 34 M.Bregar (Dante C.S.S.)


Spontaneous Generation Disproved :Spontaneous Generation Disproved 35 M.Bregar (Dante C.S.S.)


Cell Theory (classical) :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) 36 M.Bregar (Dante C.S.S.)


Cell Theory (modern) :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 37 M.Bregar (Dante C.S.S.)


Cell Specialization :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) 38 M.Bregar (Dante C.S.S.)


Examples of Cells :Examples of Cells Amoeba Proteus Plant Stem Red Blood Cell Nerve Cell Bacteria 39 M.Bregar (Dante C.S.S.)


Compound Light Microscope :Compound Light Microscope M.Bregar (Dante C.S.S.) 40 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