Module 1 - Cells as the basis of life

Question 1

Magnification

Answer 1

How many times larger the object appears to be in the microscope

Question 2

Resolution

Answer 2

How well 2 very small and close objects can be distinguished by the microscope (how much detail can be seen)

Question 3

Features of a Stereomicroscope

Answer 3

• Similar to compound light microscope
• Used to view whole organisms or microscopic samples
• Very low magnification

Question 4

Features of Compound Light Microscopes

Answer 4

• Uses light as an illumination source -> forming coloured images
• Can use thick samples
• Samples in air -> to view live specimens
• Low Magnification ( x1500 max)
• Low resolution (up to 200nm)
• Portable & relatively cheap

Question 5

Features of Electron Microscopes

Answer 5

• Uses electrons an an illumination source -> forming black and white images
• Very thin samples needed
• Requires cells to be in a vaccum -> cannot view live samples as cells will die without air
• High magnification (up to x2,000,000) (used to view organelles)
• High resolution (up to 0.4nm)
• Not portable + very expensive

Question 6

What are the two types of Electron Microscopes?

Answer 6

• SEM
• TEM

Question 7

Function of SEM

Answer 7

SEM microscopes create an image by detecting reflected or knocked-off electrons off the surface of a sample. This is better for viewing external surfaces of larger specimens.

Question 8

Function of TEM

Answer 8

TEM microscopes create an image by detecting electrons that have passed through the sample. This better for viewing smaller internal structures.

Question 9

Function of Slide (parts of a microscope)

Answer 9

Where specimen is positioned on

Question 10

Function of coarse adjustment

Answer 10

Brings specimen into view without fine detail

Question 11

Function of Mirror

Answer 11

Used to shine light on the object being viewed

Question 12

Function of Revolving nosepiece

Answer 12

Holds lens of different strengths, revolves

Question 13

Function of Clips

Answer 13

Holds slide in position on stage

Question 14

Function of Cover slip

Answer 14

Covers specimen on slide

Question 15

Function of Diaphragm

Answer 15

Adjusts light (brightness)

Question 16

Function of Arm

Answer 16

Joins the base to the nosepiece

Question 17

Function of the eyepiece

Answer 17

Eye is positioned on this to view the object

Question 18

Function of fine adjustment

Answer 18

Turning the knob brings fine detail into focus

Question 19

Function of objective lens

Answer 19

Magnifies specimens -> various magnifications

Question 20

Function of the Base

Answer 20

stand or “bottom” of the microscope

Question 21

Which microscope would best be used for a highschool student who wishes to view his frog dissection a little more closely?

Answer 21

A stereo microscope would best be used, as the student is viewing a microscopic sample.

Question 22

Which microscope would best be used for a scientist studying the mitochondria within plant cells?

Answer 22

Transmission electron microscopes is best used as the scientist is viewing smaller internal structures.

Question 23

Which microscope would best be used for a person viewing a thin slice of muscle tissue cells?

Answer 23

Transmission electron microscopes is best used as the person can view a thin slice and see the internal features of the muscle cells at a higher resolution.