Microscopy And Cells (lab 1)

Question 1

What does the iris diaphragm do?

Answer 1

Maximizes the resolution of the microscope

Question 2

When should you use the focus (course) knob?

Answer 2

Only on 4X

Question 3

When should you use the focus (fine) knob?

Answer 3

Only on 10X and 40X

Question 4

What are the field of diameter views on 4x, 10x, and 40x?

Answer 4

4x = 4.40mm
10x = 1.75mm
40x = 0.44mm

Question 5

How do you calculate the actual size of cell (or organism)?

Answer 5

Actual size = diameter of field of view/ number of cell or organisms can fit across field of view

Question 6

What are the four basic structural features all living organisms share?

Answer 6

1. DNA
2. Ribosomes
3. Cytoplasm
4. Plasma membrane

Question 7

What are the two types of light microscopy?

Answer 7

1. Fluorescence microscopy
2. Confocal laser scanning microscopy

Question 8

Fluorescence microscopy

Answer 8

Fluorescent molecules absorb one particular wavelength of light and emit some of that absorbed light at another wavelength. Due to its high sensitivity, fluorescent dyes and antibody dye complexes are used to label specific molecules (proteins, DNA) or organelles within the cell

Question 9

Confocal laser scanning microscopy

Answer 9

Involves focusing a laser light source onto a very thin plane. This type of microscopy is used to examine specimens that are too thick to be examined with fluorescence microscopy. Specimens can be constructed into a three-dimensional image

Question 10

Electron microscopy

Answer 10

Electron microscopes are useful for examining very small objects, such as the internal structure of cells. Electron microscopes have a greater resolving power (resolution) than light microscopes.

Question 11

What are the two types of electron microscopes?

Answer 11

1. Transmission Electron Microscopy (TEM)
2. Scanning Electron Microscopy (SEM)

Question 12

What is TEM?

Answer 12

In TEM, a beam of electrons is transmitted through an extremely thin section of a specimen. The TEM has the best resolution of the internal organization of cells and their organelles.

Question 13

What is SEM?

Answer 13

In SEM. A beam of electrons is scanned over the surface of a specimen resulting in a detailed three-dimensional image of the surface of the specimen. Used for intact specimens such as insects and pollen grains

Question 14

What is the iris diaphragm used for?

Answer 14

Part of a compound microscope can be adjusted to maximize the resolution

Question 15

What is the condenser used for?

Answer 15

Used to focus the light at the level of the specimen

Question 16

What is a capsule?

Answer 16

A capsule is a gelatinous outer covering that some bacteria cells have

Question 17

What is a flagella used for?

Answer 17

Used for locomotion in some bacteria

Question 18

Would an environment with low pollution index be “healthy” ?

Answer 18

No, because environment would not be suitable for living

Question 19

What microscope uses molecules that emit absorbed light to label molecules or organelles within a cell?

Answer 19

Fluorescent

Question 20

Name the subtype of this microscope that focuses on thin planes and can use a computer to make a three-dimensionless image

Answer 20

Confocal laser scanning microscope

Question 21

Electron microscopes have a higher ________ than light microscopes because they use beams of _______ rather than light

Answer 21

1. Resolving power
2. Electrons

Question 22

Which type of electron microscopy might you use to view cilia on the outside of a paramecium?

Answer 22

SEM

Question 23

Which type of electron might you use to count the number of mitochondria within a muscle cell?

Answer 23

TEM

Question 24

Which type of microscopy might you use to identify the location of a particular protein within a cell?

Answer 24

Fluorescence