Lab Exam Review Multiple Choice

Which labeled cellular structure on your cardiac muscle image separates and protects the cell from the environment?

cell membrane

Which structure in the cheek cells did you observe that separates and protects the cell from the environment?

cell membrane

Which cellular structures that you observed using the microscope are common to all eukaryotes and prokaryotes?

cell membrane, cytoplasm

What organelles or cellular structures were common to all the different organisms looked at with the microscope?

cell membrane, cytoplasm, nucleus

Which structure did you see in the eukaryotic cells that is absent in the prokaryotes?

nucleus

Where are the lab supplies located in the lab?

on the shelf above the workbench

You were asked to label the cytoplasm on your Spirogyra image. What is the function of the cytoplasm?

to contain all the substances needed to keep the cell alive

Gas constant R

0.082 (L/atm)/(K/mol)

Order light intensity from least to most oxygen production.

1, 2, 3, 4, 5

How much slower would hydrogen peroxide likely be decomposed if catalase was not available in cells?

1,000,000 times

What was the pressure in the Erlenmeyer flask after the addition of 40 mL of water?

1.282 atm

Average of four-volume changes in photosynthesis in experiment 1

1.9 mL

What volume does the air occupy in the empty Erlenmeyer flask?

182 mL

At which pH level(s) did catalase fail to function?

2

Which of the solutions that you tested with iodine solution had positive results?

2% starch solution

Which of the solutions that you tested with iodine solution turned bluish black?

2% starch solution

At which temperature did catalase function at the slowest rate, but still produce gas?

21.5

What was the initial temperature displayed on the thermometer before adding the NaOH to the HCl?

21.5 ºC

Which temperature generated the greatest oxygen production?

30

At which temperature did the catalase enzyme function at its best?

40

Which of the following states a characteristic of a scientific hypothesis?

A scientific hypothesis is more general than a prediction for an experiment. A scientific hypothesis can be tested by more than one experiment. A scientific hypothesis is based on observation.

Of the four cell types that you observed in the lab, which was the largest? Remember the total magnification notes on your images.

Amoeba cell

What is the relationship between the rate of photosynthesis and light intensity?

As light intensity increases at first, the rate of photosynthesis increases as well. However, eventually the rate of photosynthesis levels off, despite further increases in light intensity.

Why did the catalase function level off when different hydrogen peroxide concentrations were tested?

At some point, all the catalase in solution was catalyzing reactions, so even if the hydrogen peroxide concentration was increased, the rate of the reaction could not increase any more.

What happened to the hydrochloric acid solution when zinc was added?

Bubbles formed.

Which of the following is an image of iodine solution and 2% starch solution?

Dark Blue

Suppose two students were experimenting with yeast to study cellular respiration. One student found glucose to be the most efficiently consumed sugar by yeast, whereas the other student found maltose to be the most efficiently consumed sugar by yeast. Which of the following could explain the results?

Either of the two answer choices could explain the results.

Refer to your observations of the shapes of the organisms that do and do not have cell walls. What effect does the cell wall have on the shape of the organism?

It restricts the cell shape. The Spirogyra cells are fairly uniform rectangles. Animal and Amoeba cells had more variable shapes.

What color changes did you observe when you added Sudan III solution to water?

It stayed colorless, but with a thin, red layer on top.

Why can Benedict's solution be used to distinguish between glucose and sucrose?

Glucose is a reducing sugar, and sucrose is not a reducing sugar.

When instructed to record observations, data, or notes, where should you record the information?

In a notebook or other document to reference later when completing the assignment

What is the function of the nucleus in the Euglena cells you observed?

It contains DNA and controls the cell.

What is the function of the cell wall in the onion cell you looked at?

It protects the cell and provides shape and support.

What color changes did you observe when you added Benedict's solution to water and heated it?

It turned from colorless to blue after the addition of the Benedict's solution, but stayed blue after it was heated.

What color changes did you observe when you added Benedict's solution to the 5% glucose solution and heated it?

It turned from colorless to blue after the addition of the Benedict's, but it turned red after it was heated.

What color changes did you observe when you added Sudan III solution to corn oil

It turned from yellow to orange-red.

Why can Benedict's solution not be used to distinguish between glucose and lactose, which is a disaccharide with a reducing carbonyl group?

Lactose and glucose are both reducing sugars. Benedict's solution distinguishes between reducing and nonreducing sugars.

Which of the following correctly describes the relationship between monosaccharides and starches?

Monosaccharides are the building blocks from which starches are made

Which of the following is a correctly labeled image of a Euglena cell?

Multi-colored

Is diffusion the only way materials can enter a cell?

No, a cell is capable of actively transporting materials across its membrane.

Based on your results from this lab, would you expect the hydrogen peroxide you buy from the store to bubble like soda when you open it?

No, catalase sped up the rate of the reaction. Store-bought hydrogen peroxide will decompose into water and oxygen gas much too slowly for visible bubbles to form.

Suppose a student hypothesized that mice would grow best if fed apple slices. She used four mice, all of which she incubated for seven days. She fed the first mouse apple slices, the second raw steak, the third fruit punch, and the fourth was not given any food. At the end of seven days, she found the following changes in mass for the four mice: the one fed apple slices gained 1.00 g, the one fed raw steak gained 0.61 g, the one given fruit punch gained 4.20 g, and the one given only water died by week's end. Did the results of her experiment support her hypothesis?

No. The mouse gained the most mass from the fruit punch, not the apple slices.

What caused the bubbles to form when you added the catalase to the hydrogen peroxide and water mixture at 40 °C?

Oxygen gas formed during the decomposition of hydrogen peroxide.

Which of the following is an image of biuret solution and egg white solution?

Purple Tube

Suppose a scientist was observing a new species of butterfly. He observed a new color that had not been seen in butterflies before. Was the data he collected qualitative or quantitative? Please explain.

Qualitative; observing color is descriptive.

Was the data you collected qualitative or quantitative? Please explain.

Quantitative; measuring mass is a specific measurement of a particular parameter.

Spirogyra

Teal color, square

Where are the substances required to perform the experiments located?

The Materials shelf

What results would you expect from a biuret test of chicken soup?

The biuret solution will change to purple.

What was the appearance of the Elodea cells in hypertonic solution?

The cell membrane shriveled and pulled away from the cell wall.

What was the appearance of the Elodea cells in hypotonic solution?

The cell membrane was pressed against the cell wall, and the cell was almost bursting.

What was the appearance of the Elodea cells in aquarium water?

The chloroplasts were located mostly at the periphery of the cell.

When the diffusion bag contained 20% or 15% fructooligosaccharides, the net movement of water was from the beaker to the bag. However, the change in mass was greater when the dialysis bag contained 20% fructooligosaccharides than when it contained 15% fructooligosaccharides. Why?

The concentration of fructooligosaccharides in the 20% solution was higher than in the 15% solution, so more water needed to move from the beaker to the bag to equalize the concentration.

Based on your results in Experiment 3, why do the vegetables in dressed salads wilt over time?

The dressing is a hypertonic solution because it has salt, sugar, or other spices dissolved in an aqueous base. Plasmolysis in the cells of the vegetables causes the vegetable as a whole to wilt.

Water was able to move across the dialysis membrane but the fructooligosaccharide molecules were not. Explain why this is the case.

The fructooligosaccharide molecules are larger than water molecules, and will not fit through the pores in the dialysis membrane.

What caused the changes you observed between the slides of Elodea in aquarium water and Elodea in hypertonic solution?

The hypertonic solution caused water to leave the cell. This shrunk the cytoplasm and pulled the cell membrane away from the cell walls, a condition called plasmolysis.

What was the color of the iodine solution in the diffusion bag before and after dialysis?

The iodine solution was reddish brown before dialysis and did not change color during dialysis.

Why was iodine able to diffuse across the membrane whereas starch was not?

The pores of the bag are larger than the iodine molecules but smaller than the starch molecules.

Why did you not see chloroplasts in the onion root cells?

The roots are underground and are not exposed to light. Therefore, they do not need chloroplasts

What is the scientific method?

The scientific method is a way of learning about the universe through observation and experimentation.

What was the color of the starch solution in the beaker after dialysis?

The starch solution turned bluish black after dialysis

Explain the results of the experiment in which the diffusion bag contained 5% fructooligosaccharides.

The sugar concentration was higher in the beaker than in the bag, so water moved from the bag to the beaker

Explain the results of the experiment in which the diffusion bag contained 15% sucrose.

The sugar concentration was lower in the beaker than in the bag, so water moved from the beaker to the bag.

Explain the results of the experiment in which the diffusion bag contained 20% fructooligosaccharides.

The sugar concentration was lower in the beaker than in the bag, so water moved from the beaker to the bag.

Explain the results of the experiment in which the diffusion bag contained 10% fructooligosaccharides.

The sugar concentration was the same in the beaker and the bag, so there was no net movement of water.

Why do disaccharides produce more CO2 than monosaccharides?

They are made from two monosaccharides stuck together so they can be broken down into twice as much ethanol, carbon dioxide, and energy.

What is the function of the vacuoles you saw in the Paramecium?

They store fluids, nutrients, and waste.

Suppose a student gave two mice water alone and incubated one for one day and the second for six days. The first mouse maintained its mass, and the second mouse died on the sixth day. What is the most likely explanation?

Water, without nutrients from food, is not adequate for six days.

Do the optimal conditions for catalase functioning that you found correspond with the conditions in the mammalian liver where it came from?

Yes, catalase worked best at a neutral pH and temperature of 40 °C, both of which are close to mammalian tissue conditions.

Paramecium

a protist with cilia and two types of nuclei; purple and long

What color and shape were the onion root cells?

blue and rectangular

Which cellular structure did you observe in the Spirogyra, but not in the other cells?

chloroplast

Where in the Spirogyra cell does photosynthesis, which creates the biological molecule used for fuel, occur?

chloroplasts

Which organelles' function is primarily locomotion?

cilia and flagella

In order to place something into a container you must

click on the material or instrument and drag it onto the container

Based on your results, which of the solutions that you tested with Sudan III solution contained lipids?

corn oil

Liters to milliliters

divide by 1000

Based on your results, which of the solutions that you tested contained proteins?

egg white solution

Rate of glucose consumption equation

f= 1000mw/t m-moles of sugar consumed w-molecular weight t-time in minutes

Suppose a student hypothesized that mice would grow best if fed raw pasta. He fed one mouse the raw pasta, another mouse was fed apple slices, and another mouse received no food. Both the raw pasta mouse and the control mouse had lost mass by the end of two days but the apple slice mouse gained mass. The student concludes that his hypothesis is not supported by his data. Which of the following is the next step?

generate a new hypothesis

Based on your results, which of the solution(s) that you tested with Benedict's solution contained reducing sugars?

glucose solution

Based on your results with iodine and starch, what material(s) diffused across the membrane?

iodine

Which choice describes the characteristics of the Amoeba you observed using the microscope?

irregular shape and pink color

Which biological molecules were present in the whole milk?

lipids, reducing sugars, and proteins

Moles of CO2 to moles of glucose consumed

m= n/2s m-sugar consumed n-moles of CO2 s-# of simple sugars

Change in mass equation?

mfinal-minitial= change of m

How to convert volume to moles (Ideal Gas Law)

n= PV/RT

Which of the following is not one of the commercial products produced through cellular respiration?

oxygen for medical use

Which are characteristics of the Amoeba cell you observed?

pink colored and irregularly shaped

Which food(s) had starches and protein?

potato juice

Which biological molecules were present in the onion juice?

proteins and reducing sugars

Suppose Benedict's solution was added to white grape juice and heated. The color changed from blue to orange. Based on this result, which biological molecules are present in the white grape juice?

reducing sugars

Which food(s) tested positive for proteins?

skim milk, whole milk, onions, and potatoes

What was the source of CO2 for the plant in your photosynthesis experiments?

sodium bicarbonate

Suppose iodine solution was added to a chocolate chip cookie solution and the color changed to bluish-black. Based on this result, what biological molecules are present in the chocolate chip cookie solution?

starches

What can you conclude from comparing the volume changes?

that the production of oxygen is fairly constant

At which substrate concentration(s) did catalase produce the smallest volume of gas during the experimental period?

the lowest substrate concentration

What is indicated by Benedict's solution changing from blue to orange when heated?

the presence of reducing sugars

What is iodine solution changing from reddish-brown to bluish-black an indication of?

the presence of starches or complex carbohydrates

At which substrate concentration(s) did catalase produce the greatest volume of gas during the experimental period?

the two highest substrate concentrations