PAIx Lab 2- Microscopic Introduction to the Research System

Question 1

what is kohler illumination

Answer 1

• optimizes microscope’s optical train to produce homogenously bright light free from artifacts and glare

Question 2

components of kohler illumination

Answer 2

• Components: high-density illumination source, field diaphramn, condenser diaphrahm ,and collector and condenser lenses

Question 3

how many planes conribute

Answer 3

• Four planes contribute to form conjunct planes in both the illumination and image-forming light pathways

Question 4

what are conjunct planes

Answer 4

• Conjunct planes: field diaphragm, specimen, fixed diaphragm of the ocular, and the retinals plane of the viewer

Question 5

what is the collecter lens

Answer 5

• Colletor lens or filed diaphragm collects light from the source and focuses it at the front focal plane of the sub-stage condenser’s apature diaphragm
• Consdersr transmits light to illuminate the specimen

Question 6

what does closing the field diaphragm do

Answer 6

• Closing the field diaphragm controls the width of light being transmitted to the condenser

Question 7

what does adjusting the aperture do

Answer 7

• Adjusting condenser aperture affects the angle of the light being transmitted to the specimen

Question 8

should you adjust the condenser and field diaphragm each time the microscope s used and each time the object is changed

Answer 8

yes
- Field diaphragm should be closed down when changing to higher objective

Question 9

steps of kohler illumination

Answer 9

• Steps: reduce diaphragm, focus condenser,center illumination area, open diaphragm

Question 10

advantages of kohler illumination

Answer 10

• Advantages: high contrast and even illumination, reduces image artifacts and provides high sample contrast. Also, less specimen heating. Reflection and glare eliminated

Question 11

how many moults for an aphid to become and adult

Answer 11

• 4 moults to become and adult: early instar nymph, late nymph with wing buds, adult viviparous, adalt alate

Question 12

early instar nymph

Answer 12

• early instar nymph: short antennae, fewer segments, no cauda, long rostrum

Question 13

late nymph with wingbuds

Answer 13

• late nymph with wing buds: wingless morphs produced by suppressing wing development, only those who will become altes have VISIBLE buds

Question 14

adult viviparous

Answer 14

• adult viviparous: wingless and produce eggs

Question 15

adult alate

Answer 15

• adult alate: wings. All adult

Question 16

why are more stomata open on bottom

Answer 16

• More visible stomata on bottom of leaf. More open stomata on bottom. Due to bottom of leaf being protected from sun, so closed stomata on top prevent water loss

Question 17

When setting Köhler illumination, which objective provides the most accurate outcome when centering the circle of light using the condenser centering screws (Step 7)?

Answer 17

The 40x objective since it has the smallest light opening and can focus to a greater magnification.

Question 18

Low-power and high-power objectives differ primarily in the fact that the latter have much higher numerical apertures and therefore greater resolving power. Which of the following statements is TRUE when performing Köhler illumination

Answer 18

More light is required at a higher power and is provided by opening the condenser aperture ring more to give adequate resolution of detail.

Question 19

look at paper for picture of aphids