Question | Answer |
What is the basic unit of biology? | The cell |
What did Hooke do in 1665? | He coined "cells" |
How did Hooke coin the term "cells"? | By looking at a cork and seeing the cell walls of dead plant tissue |
Who was Antonie van Leuwenhoek? | He advanced the microscope and was the first to view living cells |
What did van Leuwenhoek view? | the first living cells: Blook, sperm, bacteria, and 1 celled organisms |
What were the two factors restricting advancement in microscopes? | Limited resolution(resolving power) and the restricted descriptive nature of 17th century biology |
Define Resolving power. | The ability to see fine details |
What happened in the 1830s? | Able to see structures 1 micrometer in size |
Who was Robert Brown? | Found that plant cells have a "nucleus" |
What are the 3 main points of cell theory? | 1. All organisms consit of one or more cells
2. The cell is the basic unt of structure for all organisms
3. All cells arise only from preexisting cells |
What was the first strand of cell biology? | cytology |
Define Cytology. | Study of cells and their structures |
When did cytology first come about? | 3 centuries ago thanks to light microscopes |
What is the nanometer (nm)? | Unit of choice for molecules and subcellular structures too small to be seen using a light microscope |
In comparison to a meter, how big is a nm? | one-billionth of a meter (10^-9) |
How many nanometers in a micrometer? | 1 micrometer=1000nm |
What is the diameter of a robosome? | 25-30 nm |
What is an Angstrom? | smaller than a nm |
What is an Angstrom used to measure? | demensions within proteins and DNA molecules |
What does 1 Angstrom equal? | 0.1 nm; about the size of a hydrogen atom |
What should you use to view eukaryotic cells? | light microscope |
What should be used to view a nucleus? | light microscope |
What should be used to view mitochondria and chloroplasts? | light microscope |
What is the limit of resolution? | how far apart adjacent objects must be to appear as separate entitites |
What is resolving power? | ability to see fine details |
A small limit of resolution means a ________ resolving power. | large |
What is brightfield microscopy? | white light being passed directly through a speciment that is either stained or unstained and the background is illuminated |
What are the limitations of brightfield microscopy? | the specimens often msut be chemically fixed and are no longer alize |
What is phase-contrast and differnetial interference contrast microscopy? | made viewing living cells possible |
What is phase of light? | prcise positions of maxima nad minima as light traveles |
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