Section 1 Flashcards
Who is known as the father of biology and why?
Aristotle; he was one of the first Greek philosophers who used the Scientific Method instead of making assumptions.
Who invented the microscope? How much magnification power did it have?
Hans and Zacharias Janssen; 20x
How many lenses were used in the first microscope? Name them.
Two lenses were used; ocular and objective.
What is a compound microscope?
A microscope that uses more than one lens.
What is a simple microscope?
A microscope that only uses one lens.
What did Robert Hooke add to the microscope?
- A 3rd lens (two lenses in the ocular)
- A light source
Who came up with the term “cells”? How did they come up with it?
Robert Hooke; he was observing cork under his microscope and noticed chambers, which he named cells.
In Latin, what does “cell” mean?
Small compartment.
Name an example of how microscopy affects surgery.
Laparoscopic surgery.
How many lenses did Antoni Van Leeuwenhoek’s microscope have? What was its magnification?
One lens; 250x
Antoni Van Leeuwenhoek was the first person to…
observe the movement of living single celled organisms (eg. bacteria, sperm).
Robert Hooke’s chambers ended up being…
the remnants of living cells.
What is the function of an eyepiece/ocular lens? What is its usual magnification?
Used to observe the specimen. It usually has a magnification of 10x.
What is the function of the coarse adjustment knob?
It moves the stage or objective lens up/down.
What is the function of the fine adjustment knob?
Used to produce a clear, sharp, image.
What is the function of the revolving nosepiece?
It holds the objective lenses: rotates those lenses and helps change the magnification power.
What is the function of the objective lenses? How many do most compound microscopes have?
- Zooms into the specimen
- Can have a low, medium, or high magnification
- Most compound microscopes have three
What is the function of the stage?
It is where the specimen is put for observation.
What is the function of the stage clips?
It holds the slide in place.
What is the function of the diaphragm?
It adjusts the diameter of an opening to control the amount of light passing through the specimen.
What is the function of the lamp/mirror?
The lamp supplies the light required to view the specimen. Sometimes a mirror is used, which directs lights from its surroundings through the diaphragm.
What is the function of the arm?
Used to transport microscopes. Supports the microscope head and attaches it to the base.
What is the function of the base?
Used to transport microscopes. It houses illumination and supports the compound microscope.
What lens improved the amount of detail that could be seen?
The achromatic lens.
What is magnification?
It tells us how much larger (or smaller) the picture is than the real size of the specimen.
Equation:
Magnification =
(power of objective lens) (power of ocular lens)
How many micrometers are in a millimeter?
1000
What is field of view? What can it be referred to as?
Field of view is the entire area that can be seen with a microscope with a particular lens power. It can be referred to as “field diameter” or “field area.”
When the magnification ____________ (increases/decreases), the field diameter decreases.
Increases.
Equation:
higher-power field diameter
————————————— =
Low-power field diameter
low-power magnification/
high-power magnification
Equation:
actual size of an object =
of objects estimated to fit across field of view/field diameter
field diameter/# of objects estimated to fit across field of view
Equation:
scale =
diagram size of object/actual size
Name an example of science contradicting beliefs.
Galileo with his heliocentric model of the universe.
What is spontaneous generation? What is responsible for it? When was it accepted until?
Spontaneous generation is the belief that living things can emerge from non-living matter. People believed that there was a “life force” that caused non-living things to produce/”birth” living things. It was widely accepted until the 19th century.
Explain Francesco Redi’s experiment.
- He questioned spontaneous generation (did not think that maggots appeared spontaneously from raw meat)
- Set out flasks with raw meat, one with access to air, one without
- Maggots were found in the open flasks (flies laid eggs)
Did Francesco Redi’s experiment change the idea of spontaneous generation?
No, it did not, despite the evidence disproving it. Other scientists said that air was an ingredient in life force.
Explain John Needham’s experiment.
- He boiled chicken broth, put it in a flask, and sealed it
- Although it was boiled, micro-organisms still appeared
Did John Needham’s experiment change the idea of spontaneous generation?
Yes, it did. Through his experiment, he suggested that there was a life force that produced spontaneous generation. This became widely accepted.
Explain Lazzaro Spallanzani’s experiment.
- Proposed that there were micro-organisms in the air responsible for new growth.
- Repeated Needham’s experiment but drew off the air in the flask
- Nothing grew
Did Lazzaro Spallanzani’s experiment change the idea of spontaneous generation?
No, it did not. Critics suggested that he only proved that air was required for spontaneous generation.
Explain Louis Pasteur’s experiment.
- Set up two flasks with the same boiled meat broth.
- Flasks had bent s shaped necks; open to air, not dust
- Did not become cloudy with microbial growth
- When a neck was removed, bacteria grew.
Did Louis Pasteur’s experiment change the idea of spontaneous generation?
Yes, it was the decisive proof to reject spontaneous generation. It showed that micro-organisms are not generated, but rather carried in the air, too small to see.