BIOLOGY FOR LIFE
  • Syllabus
    • Core >
      • 1: Cell Biology >
        • 1.1: Introduction to Cells
        • 1.2: Ultrastructure of Cells
        • 1.3: Membrane Structure
        • 1.4: Membrane Transport
        • 1.5: The Origin of Cells
        • 1.6: Cell Division
      • 2: Molecular Biology >
        • 2.1: Molecules to Metabolism
        • 2.2: Water
        • 2.3: Carbohydrates and Lipids
        • 2.4: Proteins
        • 2.5: Enzymes
        • 2.6: DNA and RNA
        • 2.7: DNA Replication, Transcription and Translation
        • 2.8: Cell Respiration
        • 2.9: Photosynthesis
      • 3: Genetics >
        • 3.1: Genes
        • 3.2: Chromosomes
        • 3.3: Meiosis
        • 3.4: Inheritance
        • 3.5: Genetic Modification and Biotechnology
      • 4: Ecology >
        • 4.1: Species, Communities and Ecosystems
        • 4.2: Energy Flow
        • 4.3: Carbon Cycling
        • 4.4: Climate Change
      • 5: Evolution and Biodiversity >
        • 5.1: Evidence for Evolution
        • 5.2: Natural Selection
        • 5.3: Classification and Biodiversity
        • 5.4: Cladistics
      • 6: Human Physiology >
        • 6.1: Digestion and Absorption
        • 6.2: The Blood System
        • 6.3: Defense Against Infectious Disease
        • 6.4: Gas Exchange
        • 6.5: Neurons and Synapses
        • 6.6: Hormones, Homeostasis and Reproduction
    • Higher Level >
      • 7: Nucleic Acids >
        • 7.1: DNA Structure and Replication
        • 7.2: Transcription and Gene Expression
        • 7.3: Translation
      • 8: Metabolism, Cell Respiration & Photosynthesis >
        • 8.1: Metabolism
        • 8.2: Cell Respiration
        • 8.3: Photosynthesis
      • 9: Plant Biology >
        • 9.1: Transport in the Xylem of Plants
        • 9.2: Transport in the Phloem of Plants
        • 9.3: Growth in Plants
        • 9.4: Reproduction in Plants
      • 10: Genetics and Evolution >
        • 10.1: Meiosis
        • 10.2: Inheritance
        • 10.3: Gene Pools and Speciation
      • 11: Animal Physiology >
        • 11.1: Antibody Production and Vaccination
        • 11.2: Movement
        • 11.3: Kidney and Osmoregulation
        • 11.4: Sexual Reproduction
    • Options >
      • D: Human Physiology >
        • D.1: Human Nutrition
        • D.2: Digestion
        • D.3: Functions of the Liver
        • D.4: The Heart
        • D.5: Hormones and Metabolism
        • D.6: Transport of Respiratory Gases
  • IB Requirements
    • Learner Profile
    • Group 4 Project
    • External Exam
    • Internal Assessment >
      • Personal Engagement
      • Exploration
      • Analysis
      • Evaluation
      • Communication
    • Extended Essay
  • Investigation Skills
    • Lab Safety
    • Microscopy
    • Lab Drawings
    • Data Tables
    • Measurement
    • Statistics >
      • Descriptive Statistics >
        • Skew
        • Measures of Central Tendancy
        • Measures of Spread
        • Pearson Correlation
      • Inferential Statistics >
        • T-Test
        • ANOVA
        • Kruskal-Wallis
        • X2 Test for Independence
        • X2 Goodness of Fit
    • Graphing >
      • Graphing with Excel
      • Interpreting Error Bars
    • Error Analysis
  • Course Info
    • Above & Beyond >
      • Biology Club
      • Pumpkin Carving
      • Scavenger Hunt
      • Science News
      • IB Bio Dance
      • Wood Duck Project
      • Invasive Crayfish Project
    • Assessment >
      • Class Grading IB Bio I
      • Class Grading IB Bio II
      • Daily Quizzes
      • Lab Practicals
    • Class Photos
    • Recommendations
    • Supplemental Reading
  • Contact
  • About
    • Philosophy
    • Resume
    • Reflection
    • Site Feedback
    • Favorite Quotes
    • AEF Blog
  • Expeditions
    • Bahamas (2009)
    • Trinidad (2010)
    • Trinidad (2011)
    • Ecuador (2012)
    • Trinidad (2013)
    • Peru (2014)
    • Bahamas (2015)
    • Peru (2016)
    • Costa Rica (2017)
    • Costa Rica (2018)
    • Arizona (2022)
    • Florida (2023)
  • Summer Ecology Research

Microscopy

Magnifying Power
A compound microscope has two sets of lenses. The lens you look  through is called the ocular. The lens near the specimen being examined is called the objective. The objective lens is one of three or four lenses located on a rotating turret above the stage, and that vary in magnifying power. The lowest power is called the low power objective (LP), and the highest power is the high power objective (HP). 
 
You can determine the magnifying power of the combination of the two lenses by multiplying the magnifying power of the ocular by the magnifying power of the objective that you are using. For example, if the magnifying power of the ocular is 10 (written 10X) and the magnifying power of an objective is 4 (4X), the magnifying power of that lens combination is 40X.  
Picture
Field of View (FOV)
The field of view is the maximum area visible through the lenses of a microscope, and it is represented by a diameter. To determine the diameter of your field of view, place a transparent metric ruler under the low power (LP) objective of a microscope. Focus the microscope on the scale of the ruler, and measure the diameter of the field of vision in millimeters.  Record this number.
 
When you are viewing an object under high power, it is sometimes not possible to determine the field of view directly. The higher the power of magnification, the smaller the field of view. 
Picture
The diameter of the field of view under high power can be calculated using the following equation:
Picture
For example, if you determine that your field of view is 2.5 mm in diameter using a 10X ocular and 4X objective, you will be able to determine what the field of view will be with the high power objective by using the above formula. For  this example, we will designate the high power objective as 40X.
Picture
Estimating the Size of the Specimen Under Observation
Objects observed with microscopes are often too small to be measured conveniently in millimeters.  Because you are using a scale in millimeters, it is necessary to convert your measurement to micrometers. Remember that 1 μm = 0.001 mm.
 
To estimate the size of an object seen with a microscope, first  estimate what fraction of the diameter of the field of vision that the object occupies. Then multiply the diameter you calculated in micrometers by that fraction. For example, if the field of vision’s diameter is 400 μm and the object’s estimated length is about one-tenth of that diameter, multiply the diameter by one-tenth to find the object’s length.
Picture
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"When we try to pick out anything by itself, we find it hitched to everything else in the Universe." 
 John Muir,   1911
  • Syllabus
    • Core >
      • 1: Cell Biology >
        • 1.1: Introduction to Cells
        • 1.2: Ultrastructure of Cells
        • 1.3: Membrane Structure
        • 1.4: Membrane Transport
        • 1.5: The Origin of Cells
        • 1.6: Cell Division
      • 2: Molecular Biology >
        • 2.1: Molecules to Metabolism
        • 2.2: Water
        • 2.3: Carbohydrates and Lipids
        • 2.4: Proteins
        • 2.5: Enzymes
        • 2.6: DNA and RNA
        • 2.7: DNA Replication, Transcription and Translation
        • 2.8: Cell Respiration
        • 2.9: Photosynthesis
      • 3: Genetics >
        • 3.1: Genes
        • 3.2: Chromosomes
        • 3.3: Meiosis
        • 3.4: Inheritance
        • 3.5: Genetic Modification and Biotechnology
      • 4: Ecology >
        • 4.1: Species, Communities and Ecosystems
        • 4.2: Energy Flow
        • 4.3: Carbon Cycling
        • 4.4: Climate Change
      • 5: Evolution and Biodiversity >
        • 5.1: Evidence for Evolution
        • 5.2: Natural Selection
        • 5.3: Classification and Biodiversity
        • 5.4: Cladistics
      • 6: Human Physiology >
        • 6.1: Digestion and Absorption
        • 6.2: The Blood System
        • 6.3: Defense Against Infectious Disease
        • 6.4: Gas Exchange
        • 6.5: Neurons and Synapses
        • 6.6: Hormones, Homeostasis and Reproduction
    • Higher Level >
      • 7: Nucleic Acids >
        • 7.1: DNA Structure and Replication
        • 7.2: Transcription and Gene Expression
        • 7.3: Translation
      • 8: Metabolism, Cell Respiration & Photosynthesis >
        • 8.1: Metabolism
        • 8.2: Cell Respiration
        • 8.3: Photosynthesis
      • 9: Plant Biology >
        • 9.1: Transport in the Xylem of Plants
        • 9.2: Transport in the Phloem of Plants
        • 9.3: Growth in Plants
        • 9.4: Reproduction in Plants
      • 10: Genetics and Evolution >
        • 10.1: Meiosis
        • 10.2: Inheritance
        • 10.3: Gene Pools and Speciation
      • 11: Animal Physiology >
        • 11.1: Antibody Production and Vaccination
        • 11.2: Movement
        • 11.3: Kidney and Osmoregulation
        • 11.4: Sexual Reproduction
    • Options >
      • D: Human Physiology >
        • D.1: Human Nutrition
        • D.2: Digestion
        • D.3: Functions of the Liver
        • D.4: The Heart
        • D.5: Hormones and Metabolism
        • D.6: Transport of Respiratory Gases
  • IB Requirements
    • Learner Profile
    • Group 4 Project
    • External Exam
    • Internal Assessment >
      • Personal Engagement
      • Exploration
      • Analysis
      • Evaluation
      • Communication
    • Extended Essay
  • Investigation Skills
    • Lab Safety
    • Microscopy
    • Lab Drawings
    • Data Tables
    • Measurement
    • Statistics >
      • Descriptive Statistics >
        • Skew
        • Measures of Central Tendancy
        • Measures of Spread
        • Pearson Correlation
      • Inferential Statistics >
        • T-Test
        • ANOVA
        • Kruskal-Wallis
        • X2 Test for Independence
        • X2 Goodness of Fit
    • Graphing >
      • Graphing with Excel
      • Interpreting Error Bars
    • Error Analysis
  • Course Info
    • Above & Beyond >
      • Biology Club
      • Pumpkin Carving
      • Scavenger Hunt
      • Science News
      • IB Bio Dance
      • Wood Duck Project
      • Invasive Crayfish Project
    • Assessment >
      • Class Grading IB Bio I
      • Class Grading IB Bio II
      • Daily Quizzes
      • Lab Practicals
    • Class Photos
    • Recommendations
    • Supplemental Reading
  • Contact
  • About
    • Philosophy
    • Resume
    • Reflection
    • Site Feedback
    • Favorite Quotes
    • AEF Blog
  • Expeditions
    • Bahamas (2009)
    • Trinidad (2010)
    • Trinidad (2011)
    • Ecuador (2012)
    • Trinidad (2013)
    • Peru (2014)
    • Bahamas (2015)
    • Peru (2016)
    • Costa Rica (2017)
    • Costa Rica (2018)
    • Arizona (2022)
    • Florida (2023)
  • Summer Ecology Research