Biol 61 Lab Exam 1 (labs 0-4) (copy)

what is the study cycle?

preview, attend, review, study, assess

how many times a day should you incorporate intense study sessions?

3-5

What are 3 types of note taking?

cornell, outlining, annotating ppt

dependent variable

The outcome factor; the variable that may change in response to manipulations of the independent variable.

independent variable

The experimental factor that is manipulated; the variable whose effect is being studied.

controls

experimental conditions that remain constant -- helps you determine whether your experimental design is valid and the results due to the independent variable and not smt else

Cells are separated from their environment by a ..... that is difficult for many types of substances to cross directly

phospholipid-bilayer plasma membrane

Cells will contain protein pores, channels and transporters that can allow the movement of certain ________ across membranes

molecules

phospholipid bilayer membranes of cells are selectively ____________

permeable

only certain molecules are allowed to pass freely across the membrane and so cells can determine what substances are allowed to pass across membranes based on ...

what proteins they make

The simplest way molecules can move across membranes is via ___________

diffusion

diffusion?

describes the net movement of molecules from an area of high concentration to one of low concentration until equilibrium is reached

properties of diffusion:

-what powers the movement? -______________ movement describes this motion

intrinsic KE

Brownian

Is diffusion passive or active?

passive (no nrg needed)

facilitated diffusion

diffusion with aid of channel or carrier protein (a type of passive transport)

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

osmosis

Describes the diffusion of water across a membrane from a region of high concentration to a region of low concentration

when does osmosis occur?

Occurs when an unequal [solute] is found on opposite sides of a selectively permeable membrane

-The membrane is impermeable to these solutes -water molecules are doing the diffusing

what is an osmotically active substance (OAS)?

solute that causes the concentration difference

-[solute] expressed as molarity (mol/L)

A solution with a higher concentration of dissolved solutes has a ____________ osmolarity and __________ osmotic pressure (the pressure needed to keep water from diffusing into it)

higher ; greater

osmotic pressure

pressure that must be applied to prevent osmotic movement across a selectively permeable membrane

tonicity refers to...

the osmotic pressure of 2 solutions separated by a membrane permeable to h2o

hypotonic

a solution has a lower (hypo means below) solute concentration

hypertonic

solution has a higher (hyper means above) solute concentration

isotonic

solute concentration is the same across membrane

serological pipettes are for transferring liquids in which range?

1-25 mL

in serological pipettes, total volume of ____ mL and each large line marks 1 mL and smaller lines mark 0.1 mL

5

for serological pipettes, draw up liquid using the ...

pipette pump

for serological pipettes, measure using the ________ of the liquid

meniscus (bottom of concave surface)

how do you calculate percent error

(expected-observed)/expected x 100

Micropipettes are used to accurately transfer ...

small volumes of liquid

how is a micropipette held?

straight

P20 micropipette

2-20 ul

P200 micropipette range

20-200 ul

P1000 micropipette

100-1000 ul

on a P20, what volume is this?

2 0 0

20 ul

on a P200, what volume is this?

0 5 0

50 ul

on a P1000, what volume is this?

0 7 5

750 ul

how to use micropipette?

By depressing the plunger to the first stop point and placing the tip in the liquid and slowly releasing the plunger, the exact amount to be transferred can be drawn up into the tip. To expel this volume, depress the plunger to the second stop point.

microscopes are instruments for...

magnifying biological specimens with high resolution

when storing your microscope:

turn illuminator off, set rheostat to ...

lowest setting

when storing your microscope:

which objective do you put "in click"

unoccupied objective opening, or if all spots are occupied then the shortest objective

Accuracy is the degree to which an observed value corresponds to the ....

true value.

Precision is the degree to which measurements are ...

reproducible.

Pipettes often have a small cotton plug at the upper end to protect the pump if ....

fluid is inadvertently pulled too far up the pipette.

1000 uL = _____ mL

1

should you lay down a micropipette if there is liquid in the tip?

no

the P20 micropipette uses what color tip?

clear or yellow

the P200 micropipette uses what color tip?

yellow

the P1000 micropipette uses what color tip?

blue

A microscope is always carried by grasping the ______ with one hand while supporting the _______ with the other

arm ; base

The .... is the platform on which a microscope slide is placed.

Stage clips (5) ....., and the stage controls (11) are turned to ....

mechanical stage

hold the slide in place

move the slide

Objects are viewed by looking through the __________ or eyepieces (1). The line of vision then passes through the lens of the __________ (4).

The microscope is binocular (having two eyepieces), and the distance between the oculars, termed the ......, can be adjusted by spreading apart or pushing together the. ....(2) that holds the oculars.

oculars objective

inter-pupillary distance binocular head

The ..... (3) holds the three objectives on a rotating turret: scanning (4x), low power (10x) and high power (40x).

nose piece

scanning power

4x magnification

low power

10x

high power

40x magnification

Beneath the stage is a condenser (7) which ......, and it contains an iris diaphragm which regulates .......

focuses light rays on the specimen on the slide

the amount of light passing through the condenser

The diaphragm is controlled by a ......

diaphragm lever

Light to illuminate the specimen is supplied by the .... (8).

light source

The concentric knobs on the side of the microscope are used for __________ the instrument.

The large knob is for __________adjustment (12) and the smaller one for ______ adjustment (13).

focusing

coarse

fine

The resolution limit or resolving power of a microscope lens is a measure of the microscope's ability to ....

distinguish between adjacent points on a slide

Having "high resolving power" implies that you can distinguish between points that are very ______ together and this property will give you a very sharp, precise image.

close

The human eye has a resolving power of about ...

0.1 mm

The resolving power is a function of the wavelength of light used to __________ the object and the design of the condenser (as well as the use of immersion oil with a 100X objective, but oil immersion will rarely be used in this class).

visualize

The ___________ wavelengths of visible light (blue) provide maximum resolution. This is why a blue filter is normally used over the light source

shortest

The best compound microscope lenses have a resolving power of about 0.2 mm (1 mm = 1 micrometer = 1 micron = 1/1000 mm or 1/25,000 inch).

This means that two objects 0.2 mm apart will be seen as __________ entities, but if they are closer than this they will be seen as a single object because their images will ....

separate

fuse together.

When using the microscope, a simple way to increase resolution is to open the ...., letting in more light.

Resolution will increase, but the image will tend to wash out and contrast will decrease.

iris diaphragm

The magnification of an object is simply how many times larger the object appears in the microscope as compared to its size as seen with the ....

unaided eye.

The magnification is represented by a number which is calculated as the product of the......

powers of the ocular and objective lenses

If a 10X objective is used with a 10X ocular, the magnification is ______.

If the same ocular is used with the oil immersion 100X objective, the magnification is _________.

100X

1000X

How do things appear under a microscope?

larger, flipped upsidedown and backwards

If you move the slide to the right, which way does the image appear to move?

left

If you move the slide to the left, which way does the image appear to move?

RIGHT

If you move the slide towards you, which way does the image appear to move?

AWAY

Microscopes should be parfocal, that is, when the image is in focus under low power, it will be nearly in focus when ...

a higher power objective is rotated into position

the field, which is the area of observation or the area that you can see under the microscope, gets _____________with increased magnification

smaller

working distance is the distance between the slide and the ,,,.

That distance will continue to __________ as power increases

That means that you should only use the ______ focus at high powers or you might smash the slide

objective lens

lessen

fine

Lastly, as the power increases the depth of field will get ________-.

The depth of field is the amount of the object that is ...

smaller

in focus at one time.

If the depth of field is _________ and the object is thick, then you will clearly see through the object with most parts in focus.

large

If the depth of field gets __________, then only a tiny portion of the object (an optical section) will be in focus, and the areas above and below the plane of focus will be fuzzy.

To view the other parts, you would need to scan the object up and down with the fine adjustment knob, observing one tiny optical section at a time. By combining these sections in your mind, a three-dimensional mental image can be constructed.

small

One should always locate the object to be viewed with the .... first; then center the object to be examined before switching to a higher magnification. If the object is lost because the slide is moved slightly or the object itself moves, simply switch to the lower magnification (larger field), center the object again, switch back to high power and you can continue your work quickly, with a minimum of effort.

scanning 4x objective

Protists are widespread __________ cells that are generally small in size and live in water or on soil.

eukaryotic

Most protists are __________ organisms, however a few are colonial or multicellular.

unicellular

Spirogyra is a filamentous green algae related to _______ plants.

It has _________-shaped cells arranged in a filament, and a helical chloroplast (hence the name Spirogyra).

land

barrel

Euglena is a unicellular alga that bears ____ flagella on its anterior end, one long and one very short, with which the cell moves.

two

Paramecium is a unicellular, heterotrophic ciliate that moves by means of thousands of tiny _______ which cover the cell surface. The culture may contain other species of protists that are included as a food source for Paramecium.

cilia

Amoeba is a unicellular, heterotrophic protozoan that moves by means of streaming __________, with which it engulfs its prey. They are very slow moving

pseudopodia

Our example animal is the tiny tardigrade, also called a ...

water bear

with the dissecting (stereoscopic) microscopes, the image is formed from ..... and has considerable depth of field bc the magnification powers are generally ____

reflected light

low

true or false: a cover slip is used when making a wet mount.

true

selectively permeable membrane:

small nonpolar substancesz (hydrophobic) cross ________

freely

selectively permeable membrane:

polar and charged substances (hydrophilic) require __________ proteins to cross

transport

diffusion

movement of particles so that they spread out into the available space

Substances diffuse _______ their concentration gradient

down

(from where its more concentrated to where its less concentrated)

aquaporins

water channel proteins

aquaporins facilitate diffusion of ______

water (osmosis)

osmotic pressure is the pressure needed to stop ___________

osmosis

plant cells are turgid and the best in _______ environment

hypotonic

I2KI test

test for presence of starch, polymer of glucose. turns purple color to indicate positive results