Biology Lab exam #2

head of microscope

supports the objective lenses and ocular lenses

ocular lens (eyepiece)

This is the lens you look through to view the specimen. The ocular lens magnifies the specimen. It has a magnification of 10X.

binocular microscope

a light microscope that has two ocular lenses

Monocular microscope

A light microscope that has only one ocular lens

interpupillary distance

distance between eyepieces

pointer

in the eyepiece and can be used to point to a specific object in the field of view

field of view

the circle of light you see when looking into the microscope

objective lenses

the four lenses located on the revolving nosepiece. Include the 4X scanning lens, 10X low power lens, 40X high power lens, and 100X oil immersion lens.

arm

supports the stage and condenser lens

condenser lens

focuses light from the lamp through the specimen. height can be adjusted by an adjustment knob.

iris diaphragm

controls the amount of light passing through the specimen. It is located in the condenser. Improves contrast and detail of image.

light intensity knob

controls the amount of light allowed to pass through the lens. Does not improve contrast or detail.

stage

Supports the slide being viewed

clip

Holds the slide in place

Slide movement knobs

move the slide across the stage

coarse focus knob

moves stage up and down at low power

fine focus knob

brings an object into focus at high power

base

a stand for the microscope that houses the lamp.

General rules for microscope use

1. carry the microscope with 2 hands (one under the base and the other on the arm).

2. adjust the microscope for your personal use. never push or pull the microscope across the table. pick it up to move it.

3. check the lenses. only use lens paper and lens cleaner to clean the lens.

4. Be careful with water. It can damage the microscope.

5. Don't force it. If a part will not move any farther dont force it.

total magnification

objective lens x ocular lens

what happens to the working distance and the field of view as magnification increases?

they decrease

start with what power lens?

the lowest power (4X scanning lens)

Where do you start the stage once it is mounted and you rotate to the scanning lens?

the stage should be at its highest position so you can lower it with the coarse and fine focus knobs until it is in focus. Bringing the stage toward the object can damage the slide or objective lens.

use only what focus with high power objective lenses?

fine focus knob

Is the image right side up or upside down when looking through the microscope?

upside down

when you move the slide away from you does the image move away from you or towards you?

towards me

when moving left or right what happens to the image?

it moves in the opposite direction.

Parfocal

lens that stays in focus when magnification/focal length is changed

depth of field

the distance between the nearest and the furthest objects that give an image judged to be in focus in a camera.

working distance

distance between objective lens and specimen

only use oil with what lens?

oil immersion lens (100X)

rules for retiring a microscope

1. clean the oil immersion lens with lens cleaner and lens paper if it was used.

2. reduce light intensity to lowest level.

3. lower stage to lowest position.

4. turn revolving nosepiece so 4X lens is in place.

5. loosen the head screw and reposition the head and eyepieces from the viewing position to the storage position then tighten the screw.

6.unplug electrical cord and fold it neatly and secure it with the tie. 6. use two hands to carry the microscope.

what never to do with microscopes

1. do not turn on the light switch until the light intensity is at its lowest level. because you could burn out the bulb.

2. never use the coarse ficus with any objective lens above 10X.

3. never slide the base of the microscope across the table.

4. ise only lens paper to clean the ocular and objective lenses. never use Kim wipes or paper towels because they are too abrasive for the lenses.

5. never leave oil on a lens. clean it.

Parts of a microscope blank picture

labeled parts of microscope

how can fungi be distinguishes from bacteria?

fungi has a fuzzy appearance to its colony because of a mass of filaments called hyphae that creates a network called a mycelium.

form, elevation, and margin of bacteria colony (blank)

answer to form, elevation, and margin of bacteria colony

form

the shape of a whole colony.

Elevation

shape of colony as it rises from the plate when viewed side on.

margin

the shape of the colony's edges

coccus bacteria

spherical

bacillus bacteria

rod shaped

Spirillum Bacteria

spiral or corkscrew shaped

Gram-negative bacteria

1. more complex cell wall

2. thin peptidoglycan cell wall layer

3. outer lipopolysaccharide wall layer

4. retains safranin

5. appears pink or red

Gram-positive bacteria

1. simple cell wall

2. thick peptidoglycan cell wall layer

3. no outer wall layer

4. retain crystal violet/iodine

5. appear blue or purple

Gram staining procedure

-Dye: crystal violet 1 minute then rinse with deionized water

-Mordant: Gram's iodine 1 minute and pour off stain

-Decolorizer: 95% ethyl alcohol 15 seconds then rinse

-Counterstain: safranin stain 1 minute then rinse and let air dry.

- examine under oil immersion lens

Dinoflagellates

Euglenozoa (Euglena)

ciliates (paramecium)

dinoflagellates label perpendicular groove and cellulose plates

Diatoms (unicellular)

diatoms filamentous

plant:mnium

structure:protonema

taxonomic group:bryophyte

unlabeled male gametophye for mnium protonema bryophyte. (label the sperm and antheridia)

label the antheridia and sperm on male gametophyte for mnium protonema bryophyte

amoebozoa (amoeba)

blue-green algae (oscillatoria) 100X

not actually a protist. now a bacteria.

blue-green algae (oscillatoria) 400X

Green Algae: Spirogyra 100X

Green Algae: Spirogyra 400X

spirogyra label chloroplasts and cell

amoeba label pseudopodia

taxonomic groups of protists and examples

1. Euglenozoa-Euglena

2. Ciliates-Paramecium

3. Dinoflagellates

4. Diatoms

5. Amoebazoa-Amoeba

6. Blue-green algae

7. Green algae-Spirogyra

euglenozoa (euglena) locomotion

flagella

Euglenozoa (Euglena) nutrition

mixotrophic

Euglenozoa (Euglena) cell number

unicellular

euglenozoa (euglena) cell surface

plasma membrane

ciliates (paramecium) locomotion

cilia

ciliates (paramecium) nutrition

heterotrophic

ciliates (paramecium) cell number

unicellular

ciliates (paramecium) cell surface

cell membrane

ciliates (paramecium) special characteristics

-macronucleus and micronucleus

-posterior and anterior contractile vacuoles to maintain osmotic balance

dinoflagellates locomotion

flagella

dinoflagellates nutrition

photoautotrophic

dinoflagellates cell number

unicellular

dinoflagellates cell surface

cell wall

dinoflagellates are responsible for what 2 things?

red tide and bioluminescence

Diatoms locomotion

nonmotile

diatoms nutrition

photoautotrophic

diatoms cell number

unicellular

diatoms cell surface

exoskeleton of double shells of silica

Amoebozoa: Amoeba locomotion

amoeboid motion/pseudopodia

amoebazoa (amoeba) nutrition

heterotrophic

Amoebozoa: Amoeba cell number

unicellular

Amoebozoa: Amoeba cell surface

plasma membrane with amorphous body- no defined body shape

blue-green algae (oscillatoria) locomotion

glide (actually bacteria not protists)

blue-green algae (oscillatoria) nutrition

photoautotrophic

blue-green algae (oscillatoria) cell number

unicellular filamentous

blue-green algae reproduction

fragmentation in which filaments break off the original mat and start a new colony

Green Algae: Spirogyra locomotion

nonmotile

Green Algae: Spirogyra nutrition

photoautotrophic (same pigments as plants)

Green Algae: Spirogyra cell number

mostly unicellular

Green Algae: Spirogyra cell surface

cell wall

Paramecium shape

extended oval

Alternation of generations takes place in what 4 groups?

1. Phaeophyta

2. Rhodophyta

3. Clorophyta

4. Embryophyta

Explain alternation of generations

- the cycle of life has to go through a haploid and diploid phase

-the sporophyte generations is always diploid and makes spores via meiosis (diploid to haploid)

-the gametophyte generation is always haploid and mitosis produces gametes (sperm and eggs)

-gametrs come together via fertilization to create a zygote then it grows into an adult sporophyte (diploid) via mitosis.

what process produces the sperm and egg in plants?

mitosis

what process produces the spores in plants?

meiosis

in which structure of a plant does fertilization take place?

archegonia