quiz laboratorio #2

Question 1

5 objectives of the lab 2

Answer 1

-learn about the International System of unites (SI units)
-learn the difference between magnification, resolving power, and contrast.
-learn how to properly prepare a wet mount
-learn to identify the parts of the compound light microscope, and describe the function of each part
-learn how to properly use and take care of a microscope

Question 2

the first standardized system of measurement was proposed in _____ around the year ______

Answer 2

France and1670

Question 3

The ________ ____________ _________ is the standard system of measurement. It has been renamed __________ ____________ _______ ______()

Answer 3

-modern metric system
-International System of Units (SI units)

Question 4

There are three major parts to the metric system:

Answer 4

-the seven base units
-the prefixes
-units derived from the base units.

Question 5

table of units

Answer 5

Physical Quantity Name of unit Symbol for unit
length meter (meter) m
mass kilogram kg
time second s
electric current ampere A
temperature Kelvin K
amount of substance mole mol
luminous intensity candela cd

Question 6

NON-METRIC UNITS COMMONLY USED

Answer 6

-Liter: symbol = L. It is generally used in science and it is used in biological publications.
-Cubic centimeter: symbol = cm3. Often used for measuring the volume of solids, one cm3
equals one milliliter (mL).
-Ångström: symbol = Å. One Å equals 10-8 cm or 10-10 m

Question 7

The Meter (m)

Answer 7

The meter is the basic unit of length. The original definition was one ten-millionth of the distance from the
North Pole to the Equator.
From that, French scientists made a bar of 90% platinum and 10% iridium and put two marks on it to signify the meter distance. This particular alloy was used because it resisted expansions due to temperature and this reduced the error due to the width of the lines.
Today the meter is simply defined as the distance light travels

Question 8

second [s]

Answer 8

The second is the basic unit of time.

Question 9

The Kilogram (kg)

why wasn’t grams used?

the kilogram is defined using three numbers:

Answer 9

The kilogram is the basic unit of mass.
Until recently, it was the only basic unit still defined in
terms of a material object, and also the only one with a prefix[kilo] already in place.

• According to the International Bureau of Weights and Measures (BIPM), a kilogram was used as the original standard because a standard of one gram would have been too difficult to establish and use—due to its small mass.

-the kilogram is defined using three numbers: the constant of the Planck, and the second and the meter using the speed of the light in
the vacuum, and a fixed value of the frequency of the caesium.

Question 10

ampere [A]
basic unit of:
named after

Answer 10

The ampere is the basic unit of electric current.
It is that current which produces a specified force between two parallel wires which are 1 meter apart in a vacuum. It is named after the French physicist Andre Ampere.

Question 11

Kelvin [K]

freezin point

Answer 11

The Kelvin is the basic unit of temperature.
The freezing point of water is 273.15 K or 0 C.
Note, unlike the Fahrenheit and Celsius scales, kelvin is not in ⁰degrees—so it is expressed as K .

Question 12

mole [mol]
a mole contains

Answer 12

The mole is the basic unit of substance.
It is the amount of substance that contains as many elementary units as there are atoms in 0.012 kg of carbon-126. A mole contains 6.0221415 x 1023 atoms, molecules, particles, ions, electrons, or whatever12

Question 13

candela [cd]

Answer 13

The candela is the basic unit of luminous intensity.

It is the intensity of a source of light of a
specified frequency, which gives a specified amount of power in a given direction.

Question 14

SI derived quantities

Answer 14

Are defined in terms of the seven base quantities via a system of quantity equations. The SI derived units for these derived quantities are obtained
from these equations and the seven SI base units.

Question 15

SI derived quantities table

Answer 15

Volume Cubic meter m3
Area Square meter m2
Speed, velocity Meter per second m/s
Mass density Kilogram per cubic meter kg/m3
Specific volume Cubic meter per kilogram m3/kg
Magnetic field strength Ampere per meter A/m
Amount-of-substance of concentration—Mole per cubic meter mol/m3
Luminance Candela per square meter cd/m2

Question 16

scientific notation

Answer 16

a x 10 n where 1 ≤ a < 10 and n is an integer

el integer tiene q ser mayor o igual a 1 y menor o igual a 10

Question 17

formulas de ºc a ºf
ºf a ºc

Answer 17

°C = (°F - 32) ÷ 1.8 F

°F = (°C x 1.8) + 32

Question 18

A microscope contains _________ and is used to view detail that cannot be seen with
the naked eye. Light microscopes can extend our vision a __________ times so that objects as small as ____________ in diameter can be seen. Electron microscopes further extend our viewing capability to _____________; at this magnification, it is possible to see:

Answer 18

-one or more lenses
-thousand
-0.1 micrometer (µm)
-1 nanometer (nm)

-a virus and the outline of individual protein or
nucleic acid molecules.

Question 19

how do lenses function?

the microscope consists of?

Answer 19

Lenses function by refracting (bending) light rays. Convex lenses bend light towards a focal point. The microscope consists of a set of lenses that focus an enlarged image of an object on the retina of the eye. The greater the area of the retina covered by the
image of a specimen, the greater its magnification.

Question 20

A magnifying glass is a simple:

Answer 20

light microscope.

Question 21

When removing the microscope from the storage area, always grasp it with both hands. Place one hand around the arm and the other hand firmly under the base. Hold it close to your body for stability. Once you reach your work area, set the microscope down gently on the table with the arm toward you

Answer 21

lee

Question 22

Microscopy
involves three basic concepts:

Answer 22

-Magnification: The degree to which the image of a specimen is enlarged.

-Resolving power: How well specimen detail is preserved during the magnifying process.

-Contrast: The ability to see specimen detail against its background. Stains and dyes are added to
sections of biological specimens to increase contrast.

Question 23

Light microscopes use: ________.

Two types of light microscope and what are they used for:

.where does illumination come from?

what improves contrast?

Answer 23

-light rays that are magnified and focused using lenses

-The dissecting microscope is designed to study entire specimens in three dimensions at low magnification.
-The compound light microscope is used to observe small objects and thin slices of larger objects under higher magnifications.

-Illumination is from below, and the light passes through clear sections but does not pass through opaque
sections.

-Stains and dyes are used to improve contrast.

Question 24

Electron Microscope uses:

two types of electron microscopes, what are they used for, and their light counterparts.

Answer 24

-Electron microscopes use a beam of electrons that magnify and focus an image on a photographic plate by
means of electromagnets

-The scanning electron microscope is analogous to the dissecting light microscope. It gives an image of the surface of an object at relatively low magnifications.

-The transmission electron microscope is analogous to the compound light microscope. The object is thinly sliced and stained to improve contrast.

Question 25

comparison between light microscope and electron microscope:

Answer 25

LIGHT. ELECTRON
light lenses electromagnetic lenses
illumination by light illu. by electrons
resolution 0.1 um. resolution 1 nm
magnifies to 2000x. magnifies to 100 000x
costs hundreds of dollars. costs thousands of dollars
specimen live or dead. specimen dead

Question 26

dissecting light mic
compound light mic
scanning electron mic
transmission electron mic

Answer 26

-sperm
-bacterium
-virus
-close to DNA

Question 27

compound microscope puede ser divided ini 4 parts

Answer 27

-support structures
-lighting
-focus
-optics

Question 28

support structures (4)

Answer 28

-Arm: The handle of the microscope.

-Stage: Large platform just below the revolving nosepiece. The microscope slide is placed on the
stage with the specimen positioned directly over the opening through which light may pass.

-Stage clips: Attached to the stage and used to secure the slide in position.

-Base: The lowermost part of the microscope in contact with the table.

Question 29

lighting (3)

Answer 29

-Light (in-base illuminator) and light switch: Located in the base of the microscope.

-Diaphragm: below the stage that regulates the amount of light passing through a specimen. Correct use of the diaphragm allows for improved contrast. A lever regulates the size of the opening in the diaphragm or a rotating wheel located in front of the stage of the microscope.

-Condenser lens: Located between the diaphragm and the stage aperture. This structure converges light
rays from the light source so that they pass through the specimen on the slide and into the objective lens.

Question 30

Focus (2)

Answer 30

-Coarse adjustment knob: Larger knob used to make large, coarse adjustments when focusing on a
specimen.

-Fine adjustment knob: Located either on top of the coarse adjustment knob or separately.
Manipulating this knob makes fine adjustments when focusing on a specimen.

Question 31

Optics (3)

The compound microscope has two lens systems:

relation between objective lens and the slide

Answer 31

-an eyepiece lens that you look into and an objective lens that scans the specimen.

–Eyepiece lens: Located in the upper end of the body tube and focuses light on the retina of the eye. The
power of the eyepiece is usually 10X.

–Objective lenses: Attached to the revolving nosepiece. The number and magnification of the objective lenses
vary with the type of microscope. The objective lenses are housed in several steel tubes that are threaded into
the revolving nosepiece. The desired objective lens is placed in position by rotating the nosepiece until it
clicks into place. Most microscopes have three objective lenses: scanning lens (4X), low power lens (10X),
and high-power lens (40X) (Figure 4).

–Oil immersion lens: Attached to the revolving nosepiece. This lens will magnify 100X. A drop of immersion oil is used between the lens and the slide.

The distance between the objective lens and the slide decreases with higher magnification.

Question 32

a. Water boils at ___ ºF or ____ ºC.
b. Water freezes at ___ ºF or ___ ºC.
2. A room with a temperature of __°F is __ ºC.
3. Room temperature = __ ºC
Surface of your skin = ___ ºC
Tap water at room temperature in a 500 ml beaker = __ ºC
Hot tap water in a 500 ml beaker = ____ ºC
Ice water = ___ºC

Answer 32

-212 ºF or 100 ºC
-32 ºF or 0 ºC.

-68°F is 20 ºC

22ºC

Surface of your skin = 33.4 ºC

= 23 ºC

= 150 ºC

=5ºC