Exercise 3: The Microscope
LABEL ALL INDICATED PARTS OF THE MICROSCOPE.
LABEL ALL INDICATED PARTS OF THE MICROSCOPE.
LABEL ALL INDICATED PARTS OF THE MICROSCOPE.
LABEL ALL INDICATED PARTS OF THE MICROSCOPE.
LABEL ALL INDICATED PARTS OF THE MICROSCOPE.
EXPLAIN THE PROPER TECHNIQUE FOR TRANSPORTING THE MICROSCOPE.
WHEN TRANSPORTING THE MICROSCOPE, HOLD IT IN AN UPRIGHT POSITION WITH ONE HAND ON ITS ARM AND THE OTHER SUPPORTING ITS BASE. AVOID SWINGING THE INSTRUMENT DURING ITS TRANSPORT AND JARRING THE INSTRUMENT WHEN SETTING IT DOWN.
THE FOLLOWING STATEMENTS ARE TRUE OR FALSE. IF TRUE, WRITE T ON THE ANSWER BLANK. IF FALSE, CORRECT THE STATEMENT BY WRITING ON THE BLANK THE PROPER WORD OR PHRASE TO REPLACE THE ONE THAT IS UNDERLINED. *(UNDERLINE WORDS WILL BE IN THESE)
1. THE MICROSCOPE LENS MAY BE CLEANED (WITH ANY SOFT TISSUE).
F: FALSE; ONLY WITH SPECIAL GRIT-FREE LENS PAPER
THE FOLLOWING STATEMENTS ARE TRUE OR FALSE. IF TRUE, WRITE T ON THE ANSWER BLANK. IF FALSE, CORRECT THE STATEMENT BY WRITING ON THE BLANK THE PROPER WORD OR PHRASE TO REPLACE THE ONE THAT IS UNDERLINED. *(UNDERLINE WORDS WILL BE IN THESE)
2. THE MICROSCOPE SHOULD BE STORED WITH THE (OIL IMMERSION) LENS IN POSITION OVER THE STAGE.
F: FALSE; LOWEST-POWER OBJECTIVE
THE FOLLOWING STATEMENTS ARE TRUE OR FALSE. IF TRUE, WRITE T ON THE ANSWER BLANK. IF FALSE, CORRECT THE STATEMENT BY WRITING ON THE BLANK THE PROPER WORD OR PHRASE TO REPLACE THE ONE THAT IS UNDERLINED. *(UNDERLINE WORDS WILL BE IN THESE)
3. WHEN BEGINNING TO FOCUS, USE THE (LOWEST-POWER) LENS.
TRUE
THE FOLLOWING STATEMENTS ARE TRUE OR FALSE. IF TRUE, WRITE T ON THE ANSWER BLANK. IF FALSE, CORRECT THE STATEMENT BY WRITING ON THE BLANK THE PROPER WORD OR PHRASE TO REPLACE THE ONE THAT IS UNDERLINED. *(UNDERLINE WORDS WILL BE IN THESE)
4. WHEN FOCUSING, ALWAYS FOCUS (TOWARD) THE SPECIMEN.
F:FALSE; AWAY (SO YOU WONT GET TO CLOSE AND BREAK THE SLIDE)
THE FOLLOWING STATEMENTS ARE TRUE OR FALSE. IF TRUE, WRITE T ON THE ANSWER BLANK. IF FALSE, CORRECT THE STATEMENT BY WRITING ON THE BLANK THE PROPER WORD OR PHRASE TO REPLACE THE ONE THAT IS UNDERLINED. *(UNDERLINE WORDS WILL BE IN THESE)
5. A COVERSLIP SHOULD ALWAYS BE USED (WITH WET MOUNTS AND THE HIGH-POWER AND OIL LENSES).
F:FALSE; WITH WET MOUNTS
PLATFORM ON WHICH THE SLIDE RESTS FOR VIEWING
I. STAGE
USED TO INCREASE THE AMOUNT OF LIGHT PASSING THROUGH THE SPECIMEN
B. CONDENSER
SECURE(S) THE SLIDE TO THE STAGE
E. MECHANICAL STAGE OR SPRING CLIPS
DELIVERS A CONCENTRATED BEAM OF LIGHT TO THE SPECIMEN
D. IRIS DIAPHRAGM
USED FOR PRECISE FOCUSING ONCE INITIAL FOCUSING HAS BEEN DONE
C. FINE ADJUSTMENT KNOB
CARRIES THE OBJECTIVE LENSES; ROTATES SO THAT THE DIFFERENT OBJECTIVE LENSES CAN BE BROUGHT INTO POSITION OVER THE SPECIMEN
F. MOVABLE NOSE-PIECE
DEFINE VIRTUAL IMAGE
THE REAL IMAGE IS MAGNIFIED BY THE OCULAR LENS TO PRODUCE THE VIRTUAL IMAGE SEEN BY YOUR EYE.
DEFINE RESOLUTION
(RESOLVING POWER), THAT IS, THE ABILITY TO DISCRIMINATE TWO CLOSE OBJECTS AS SEPARATE.
THE DISTANCE FROM THE BOTTOM OF THE OBJECTIVE LENS IN USE TO THE SPECIMEN IS CALLED THE _________.
WORKING DISTANCE
ASSUME THERE IS AN OBJECT ON THE LEFT SIDE OF THE FIELD THAT YOU WANT TO BRING TO THE CENTER (THAT IS, TOWARD THE APPARENT RIGHT). IN WHAT DIRECTION WOULD YOU MOVE YOUR SLIDE?
TO THE RIGHT
THAT AREA OF THE SPECIMEN SEEN WHEN LOOKING THROUGH THE MICROSCOPE IS THE ___________.
FIELD
IF A MICROSCOPE HAS A 10X OCULAR AND THE TOTAL MAGNIFICATION AT THE PARTICULAR TIME IS 950X, THE OBJECTIVE LENS IS USE AT THE TIME IS _______X.
95
WHY SHOULD THE LIGHT BE DIMMED WHEN LOOKING AT LIVING (NEARLY TRANSPARENT) CELLS?
TO PROVIDE MORE CONTRAST FOR VIEWING THE LIGHTLY STAINED CELLS; AND A WET MOUNT WILL DRY OUT QUICKLY IN BRIGHT LIGHT BECAUSE A BRIGHT LIGHT SOURCE IS HOT (CAN DAMAGE THE CELLS)
IF, AFTER FOCUSING IN LOW POWER, ONLY THE FINE ADJUSTMENT NEED BE USED TO FOCUS THE SPECIMEN AT THE HIGHER POWERS, THE MICROSCOPE IS SAID TO BE ____________.
PARFOCAL
IF, WHEN USING A 10X OCULAR AND A 15X OBJECTIVE, THE FIELD SIZE IS 1.5 MM, THE APPROXIMATE FIELD SIZE WITH A 30X OBJECTIVE IS __________MM.
0.75 MM
IF THE SIZE OF THE HIGH-POWER FIELD IS 1.2 MM, AND OBJECT THAT OCCUPIES APPROXIMATELY A THIRD OF THAT FIELD HAS AN ESTIMATED DIAMETER OF _______MM.
0.67
SAY YOU ARE OBSERVING AN OBJECT IN THE LOW-POWER FIELD. WHEN YOU SWITCH TO HIGH-POWER, IT IS NO LONGER IN YOUR FIELD OF VIEW. WHY MIGHT THIS OCCUR? WHAT SHOULD BE DONE INITIALLY TO PREVENT THIS FROM HAPPENING?
OCCURS BECAUSE IN LOWER POWER YOU HAVE A WIDER FIELD OF VIEW AND WHEN YOU SWITCH TO A HIGHER POWER IT NARROWS YOUR VIEW AND IT BECOMES OUT OF FOCUS WHICH DOES NOT HELP.
WAYS TO PREVENT IS: CENTER THE OBJECT YOU WANT TO VIEW AS MUCH AS POSSIBLE BEFORE SWITCHING TO A HIGHER POWER AND INCREASE MAGNIFICATION SLOWLY.
DO THE FOLLOWING FACTORS INCREASE OR DECREASE AS ONE MOVES TO HIGHER MAGNIFICATIONS WITH THE MICROSCOPE?
RESOLUTION __________________________
INCREASE
DO THE FOLLOWING FACTORS INCREASE OR DECREASE AS ONE MOVES TO HIGHER MAGNIFICATIONS WITH THE MICROSCOPE?
WORKING DISTANCE ____________________________
DECREASE
DO THE FOLLOWING FACTORS INCREASE OR DECREASE AS ONE MOVES TO HIGHER MAGNIFICATIONS WITH THE MICROSCOPE?
AMOUNT OF LIGHT NEEDED ________________________
INCREASE
DO THE FOLLOWING FACTORS INCREASE OR DECREASE AS ONE MOVES TO HIGHER MAGNIFICATIONS WITH THE MICROSCOPE?
DEPTH OF FIELD ________________________________
DECREASE
A STUDENT HAS THE HIGH-DRY LENS IN POSITION AND APPEARS TO BE INTENTLY OBSERVING THE SPECIMEN. THE INSTRUCTOR, NOTING A WORKING DISTANCE OF ABOUT 1 CM, KNOWS THE STUDENT ISN'T ACTUALLY SEEING THE SPECIMEN. HOW SO?
A HIGH-DRY LENS IS A HIGH POWER, NON-OIL IMMERSION LENS. A HIGH POWER LENS WOULD HAVE A MUCH SHORTER WORKING DISTANCE THEN 1 CM. IT WOULD BE MORE LIKE A COUPLE OF MM, AT THIS POINT THE STUDENT IS LOOKING AT DUST AND IS WAY OUT OF FOCUS
DESCRIBE THE PROPER PROCEDURE FOR PREPARING A WET MOUNT.
1. THE OBJECT IS PLACED IN A DROP OF WATER (OR SALINE) ON A CLEAN SLIDE.
2. A COVER-SLIP IS HELD AT A 45 DEGREE ANGLE WITH THE FINGERTIPS.
3. IT IS LOWERED CAREFULLY OVER THE WATER AND THE OBJECT.
INDICATE THE PROBABLE CAUSE OF THE FOLLOWING SITUATIONS ARISING DURING USE OF A MICROSCOPE.
A. ONLY HALF OF THE FIELD IS ILLUMINATED.
B. FIELD DOES NOT CHANCE AS MECHANICAL STAGE IS MOVED.
A. BLOCKAGE IN THE LIGHT PATH.
B. MECHANICAL CONTACT BETWEEN THE SPECIMEN AND THE OBJECTIVE LENS