1 - Eyepiece Graticule And Stage Micrometer

Question 1

What is an eyepiece graticule

Answer 1

A piece of equipment put in the eyepiece to measure the size of an object
It is a fine scale - 1mm long

Question 2

What are the units on an eyepiece graticule

Answer 2

Units are arbitrary (unspecified) and it has no scale

Question 3

What is a stage micrometer

Answer 3

A slide with a scale that is placed on the stage of a microscope

Question 4

What is each division on a stage micrometer

Answer 4

0.01nm
It is 1mm long and is divided into 100 sections

Question 5

What does the stage micrometer allow to happen

Answer 5

Allows the graticule to be calibrated so a precise scale can be calculated at each magnification of microscope

Question 6

What is the first step for calibrating an eyepiece graticule

Answer 6

Align the eyepiece graticule (the arbitrary/unknown scale) with the stage micrometer (the known scale)

Question 7

What is the second step for calibrating an eyepiece graticule

Answer 7

Count how many divisions on the eyepiece correspond to a set number of stage micrometer divisions
For example: for every 10 stage micrometer divisions there are 21 graticule divisions

Question 8

What is the third step for calibrating an eyepiece graticule

Answer 8

Calculate how long 1 division is
For example
Micrometer : eyepiece
0.1:21
0.1/21:21/21
0.0048:21
Make sure is is in MICROMETERS
0.0048x1000=4.8 micrometers

Question 9

What must you do when looking at cells on the microscope

Answer 9

Measure the specimen using the eyepiece graticule
Convert the number of divisions to the actual length
For example
If the cell is 16 units long multiply by the length of 1 division
16x4.8=76.8 micrometers

Question 10

What must you do when looking at cells on the microscope

Answer 10

Measure the specimen using the eyepiece graticule
Convert the number of divisions to the actual length
For example
If the cell is 16 units long multiply by the length of 1 division
16x4.8=76.8 micrometers

Question 11

What should you remember to do every time?

Answer 11

Calibrate the eyepiece for every magnification and microscope

Question 12

What is the equation for finding out 1 graticule division

Answer 12

Number of micrometers / number of graticule divisions

Question 13

What is the equation for finding the actual length of the specimen

Answer 13

Graticule division x magnification factor

Question 14

What should measurements always be in

Answer 14

Micrometers

Question 15

What is the first step in looking and measuring at the specimen under the microscope?

Answer 15

Cut 3 of 2mm sections from the tip of the root of germinating garlic and add to a test tube containing 0.5cm cubed of dilute hydrochloric acid

Question 16

What is the second step in looking and measuring at the specimen under the microscope?

Answer 16

Put the test tube into a water bath at 60 degrees celcius for 5 minutes

Question 17

Why do we put the test tube of hydrochloric acid and garlic roots in a water bath

Answer 17

To break down cell walls

Question 18

What is the third step in looking and measuring at the specimen under the microscope?

Answer 18

Remove the root sections from the test tube and wash the acid off in a watch glass of water

Question 19

What is the fourth step in looking and measuring at the specimen under the microscope?

Answer 19

Put each section on a slide and add a drop of stain, break up the section with a needle

Question 20

What is the fifth step in looking and measuring at the specimen under the microscope?

Answer 20

Cover the stained garlic with a cover slip and squash the material with the slide

Question 21

What is the sixth step in looking and measuring at the specimen under the microscope?

Answer 21

Tap the cover slip slightly with the handle of the needle to release the material

Question 22

What is the final step in looking and measuring at the specimen under the microscope?

Answer 22

Examine the material through a microscope