Lab Practical 1
Justify your choice of an objective to use when starting your observation of the Euglena wet mount; if the Euglena are swimming to the left, which way should you move your slide to keep the organism in view?
Start with the lowest power objective so the field of view is the largest (scanning). Move the slide to the right.
If you use the coarse-adjustment knob to focus on an object with the high-power objective, what problems will you encounter? Explain.
The object will not be in focus anymore. The stage will be moved drastically and may also slam into the objective.
What is the order from outside to inside of the prokaryotic cell?
capsule, cell wall, plasma membrane
What states that all organisms are composed of cells and that cells come only from other cells?
cell theory
What molecule is associated with plant cell walls?
cellulose
What plant cell organelle carries out photosynthesis?
chloroplasts
What two things are found in the nucleus of a eukaryotic cell?
chromatin/DNA and nucleolus
What three units equal each other?
cm3, cc, ml
What is the color of isotonic red blood cell test tube?
dark red
What is the length of the field from one edge to the other?
diameter of field
If the amount of light passing through the condenser needs to be decreased, what microscope part should be adjusted?
diaphragm
What is the movement of molecules from an area of higher to lower concentration called?
diffusion
What is the circle visible through the lenses?
field of view
If a slide is being viewed with the high-power objective, which adjustment knob should be used to sharpen the focus?
fine-adjustment knob
In the "diffusion across the plasma membrane experiment" what was in the bag before the test and what was in it after?
glucose and starch; starch
What is the basic unit for mass?
gram (g)
What is the formula to find the high-power diameter of field (HPD)?
high-power diameter of field = low-power diameter of field x (low-power total magnification/high-power total magnification)
What kind of solution causes crenation to happen to red blood cells?
hypertonic
What solution has a higher solute (therefore, lower water) concentration than the cell?
hypertonic
Which solutions have water in them?
hypertonic and hypotonic
Which solution cause the red blood cells to shrivel up, what is this called?
hypertonic; crenation
What kind of solution causes chloroplasts to be pushed outward against the cell wall?
hypotonic
What solution has a lower solute (therefore, higher water) concentration than the cell?
hypotonic
Which solution causes the red blood cells to burst, what is this called?
hypotonic, hemolysis or cytolysis
Does water move into or out of cells that are placed in a hypotonic solution?
into
In the "diffusion across the plasma membrane experiment" why did the color of the bag change?
iodine went into it
What solution has the same concentration of solute (and therefore of water) as the cell?
isotonic
What is an advantage of the stereoscope (dissecting microscope over the compound light microscope?
it allows you to view objects in three dimensions at lower magnifications
As seen in the e experiment, what happens do the object when you look through the microscope?
it is flipped over the z-axis
What is an advantage of the metric system over the standard one?
it is in powers of ten
How is a wet mount prepared?
it is prepared by placing a drop of liquid on a slide or, if the material is dry, by placing it directly on the slide and adding a drop of water or stain. It is then covered with a cover slip
What does the plasma membrane do?
it regulates the movement of molecules into and out of the cytoplasm
What is the order for the conversions? (full names)
kilometer.hectometer.decameter.meter.decimeter. centimeter.millimeter...micrometer...nanometer... picometer
What are the unique structures for the plant cells?
large central vacuole, cell wall, and chloroplast
Which type of measurements were found in lab 2?
length, weight, volume, temperature
What is the only thing you can use to clean a lens?
lens paper
What does the condenser do on the compound microscope?
lens system below the stage used to focus the beam of light on the objective being viewed
What does the diaphragm do on the compound microscope?
lever that controls the amount of light passing through the condenser
What is the color of hypotonic red blood cell test tube?
light red
What is the unit for volume?
liter (l)
What is the difference between a longitudinal and cross section of an object?
longitudinal sections are cut lengthwise and cross sections are cut crosswise
What is the lowest margin of the water level?
meniscus
What is the basic unit for length?
meter (m)
Which system of measurement is used in science?
metric
What instruments are used to observe objects smaller than a millimeter?
microscopes
What energy (ATP) producing organelle is found in animal and plant cells?
mitochondria
How do you get the total magnification?
multiply ocular lens by objective lens
What is the name for the lenses located near the eye?
ocular
What is the movement of water across the plasma membrane called?
osmosis
Does water move into or out of cells that are placed in a hypertonic solution?
out
What word describes a microscope that remains in focus when the objective lenses are changed?
parfocal
Cytoplasm is enclosed by the what?
plasma membrane
What regulates the movement of molecules into and out of the cytoplasm?
plasma membrane
What cellular components are common to prokaryotic and eukaryotic cells?
plasma membrane, ribosomes, cytoplasm, DNA
What kind of cells lack a nucleus?
prokaryotic
In the "diffusion across the plasma membrane experiment" what was the color of the bag after the reaction?
purple
What is the color of hypertonic red blood cell test tube?
red
Which term describes the minimum distance between two objects required to distinguish them as two separate objects?
resolution
What structures associated with prokaryotic and eukaryotic cells carry out protein synthesis?
ribosomes
Which objective should be in place when the microscope is put away?
scanning
What are organelles?
small membranous bodies, each with a specific structure and function
What are the unique structures for the animal cells?
small vacuoles, centrioles
What is used to improve contrast when viewing clear portions of cells?
stains
What kind of microscope would be used to study a whole or opaque object?
stereomicroscope
What are the differences between the stereomicroscope and compound light microscope?
steromicroscopes view entire objects, compound light microscope view small, thin sections
What happens when plant cells are placed in a hypertonic solution?
the central vacuole loses water, and the cytoplasm, including the chloroplasts, pulls away from the cell wall. This is called plasmolysis
What happens when plant cells are placed in a hypotonic solution?
the large central vacuole gains water and exerts pressure, called turgor pressure. The cytoplasm, including the chloroplasts, is pushed up against the cell wall
List several types of microscopes.
Electron microscope, dissecting microscope, compound light microscope
Describe the advantages of using the metric system you discovered during the lab.
Converting between units was simple, decimals were easy to understand, and temperature scale made more sens with 0 C as freezing and 100 C as boiling
Explain how you would measure the volume of a solid object such as a rock?
I would partially fill a graduated cylinder or similar container with water and record the initial volume. Then, I would place the object in the container and record the new volume of water. Subtracting the initial volume from the final volume would give the volume of the object in ml which is also equivalent to cubic centimeters.
What is the order for the conversions? (abbreviations)
Km.Hm.Dam.M.Dm.Cm.Mm...Um...Nm...Pm
Why is it advantageous to use a standard measurement system in all sciences?
Scientists from different countries are better able to share their information if they all use a standard system
To properly measure 20 ml of water, what must be at the 20 ml mark of the graduated cylinder?
the meniscus
When cells are placed in an isotonic solution where does the water go?
there is no net movement of water
What happens to potato strips in hypotonic solutions?
they gain water and become firm
What happens to potato strips in hypertonic solution
they lose water and become flimsy
What is the relative concentration of solute (particles), and therefore also of solvent (water), outside the cell compared with inside the cell?
tonicity
What instrument is used to measure mass?
triple beam balance
What does the term compound mean?
two sets of lenses
A solution of what is isotonic to red blood cells?
0.9% NaCl
3.4 l equals how many ml?
3,400
If the total magnification of a slide is 400x and the ocular lenses are 10x, what is the magnifying power of the objective being used?
40x
What is the magnification power of the high-power objective?
40x
What is the magnification power of the scanning objective?
4x
22 C equals how many degrees F?
71.6 F
What is freezing on the Celsius temperature scale?
0
880 mm equals how many m?
0.88 m
19 mm equals how many cm?
1.9 cm
Which type of microscope should be used to view a virus that is 50nm in size? Justify your choice.
An electron microscope should be used. With the light microscope you would only see a dot. With the electron microscope you would see more details
What is boiling on the Celsius temperature scale?
100
What is the magnification power of the oil immersion objective?
100x
What is the magnification power of the low-power objective?
10x
What is the magnification power of the ocular lens?
10x
2700 mg equals how many grams?
2.7 g
In the "diffusion across the plasma membrane experiment" after it was over, when it was heated up the blue turned into orange meaning what?
Benedict's test, indicating a simple sugar (glucose) has escaped the bag
Which temperature scale is used in science?
Celsius