Bio Lab Exam

Place the steps in focusing a specimen in order, from first to last.

1.Place the slide on the stage 2.Center the slide on the stage so that light will hit the specimen 3.Move the condenser to focus light on the specimen 4.Look through both oculars to see the slide on the stage 5.Use the coarse focus and your lowest power objective to adjust the focus 6.Increase magnification by switching to 10X objective 7.Increase magnification by switching to 40X objective

Respirometers were set up that contained yeast and 2% glucose solution. Each respirometer was placed at a different temperature. The height of the bubble contained in the respirometer was measured every 5 minutes for 20 minutes. The results can be seen in the graph below. Which of the tested temperatures is optimum for yeast fermentation?

37 degrees Celsius

Tube C contained non-germinating seeds. If the initial measurement for this tube was 82mm, what was the final measurement?

76mL

When testing the temperature of catalase in the enzyme lab, why did the higher temperature affect the catalase activity?

Some of the catalase enzymes were denatured.

Which of the following is NOT a net (final) product nor a reactant of photosynthesis?

ATP

The image below shows a normally functioning mitochondrial electron transport chain. The alternative oxidase pathway diverts electrons away from the transport chain before they reach the third and fourth membrane proteins. What are the consequences of diverting these electrons from the transport chain? (Select all that apply.)

ATP synthase will generate fewer ATP per unit time. More energy will be lost as heat.

Which of the following are the final by-products of glucose oxidation during aerobic cellular respiration?

ATP, heat, carbon dioxide, and water

What is the main role of the pigment molecules?

Absorb photons and transfer light energy to the reaction center chlorophyll.

All of the following are the end products of glycolysis except

NAD+.

Which of the following binds to the active site of an enzyme?

substrate

Respirometers were set up that contained yeast and 2% glucose solution. Each respirometer was placed at a different temperature. The height of the bubble contained in the respirometer was measured every 5 minutes for 20 minutes. What is the independent variable in this experiment?

temperature

Enzymes are

proteins.

If a solution is undergoing a reaction where CO2 is being used as a reactant, what color is the phenol red-containing solution shifting toward?

red

The primary function of an enzyme or any biological catalyst is to

reduce the energy of activation and increase the rate of a reaction.

A device that can be used to measure the rate of exchange of oxygen and carbon dioxide during energy-acquiring pathways is called a

respirometer.

Based on your procedure from the pH enzyme lab, how can you accurately measure how pH alone affects an enzymes ability to function?

same amounts of enzymes and different pH values

A student set up an experiment to show the effect of light color on photosynthesis in Elodea plants. She filled two test tubes with distilled water and placed a piece of Elodea in each of the tubes. She added a drop of phenol red, which turns red in a basic solution and yellow in an acidic solution. She blew in each tube before placing the volumeters on the top of the tube. Why did she blow into the tube?

to add carbon dioxide to the tube

Most atmospheric oxygen comes from photosynthesis. From which of the following molecules is the oxygen derived?

water

The reactants of photosynthesis are

water and carbon dioxide.

In the soybean experiment, the ____ used more oxygen and the ____ used more ATP.

germinating seeds; germinating seeds

In cellular respiration, carbon dioxide is formed from the oxidation of which of the following?

glucose

Which of the following substrates is fermented most easily by yeast?

glucose

What anaerobic pathway in cellular respiration generates ATP from the breakdown of glucose?

glycolysis

Put the steps for preparing a wet mount in order, from first to last.

1. Clean the slide 2. Place a drop of specimen-containing water on the slide 3.Position the edge of the coverslip next to the drop of water 4.Drop the coverslip onto the drop of water 5.Use your lowest-power objective to view your specimen 6. Use your medium-power objective to view your specimen

During the soybean experiment the nongerminating soybeans consumed around 0.02 mL/min of oxygen. What does this tell you about the cellular respiration of the nongerminating soybeans?

A little cellular respiration was taking place but not enough for growth.

Consider the biochemical pathway below, where A, B, and C are substrates and products and E1 and E2 are the enzymes that catalyze the reactions. If Enzyme 1 (E1) is inactive, which of the following compounds will accumulate?

A only

How does cytoplasmic streaming help cells?

All of the choices are correct.

Which of the following correctly summarize the overall process of photosynthesis? (Check all that apply)

CO2 + 2H2O + hv → (CH2O) + H2O + O2 . Water is absorbed by plant roots and combines with carbon dioxide in the leaves in the presence of sunlight to produce glucose and oxygen gas. 6CO2 + 12 H2O + hv → C6H12O6 + 6O2 + 6 H2O.

The process of photosynthesis requires the starting materials

CO2 and H2O.

When testing the temperature of catalase, why did the enzyme catalase work best at 37°C? (Select all that apply.)

Catalase works best at human body temperature. Normal human body temperature is 98.6°F, which equals 37°C.

Using your pH data from the pH enzyme lab, which statement(s) below are true? (Select all that apply.)

Catalase works best at pH7. Catalase works better in alkaline environments than acidic ones.

How do multiple pigments exist if the chlorophyll extract appears green when placed on the paper?

Chromatography is a method used in differentiation of colors and chlorophyll is the green pigment in plants. The pigments tend to seem the color of reflected light. Chlorophyll pigments lack to use of the green part of the spectrum. Some colors are used while others are skipped. There are two other pigments, which appear brown, yellow, and orange. The primary pigment in green plants is chlorophyll. The method of separation of colors is known as paper chromatography. Separation of stains is done according to solubility and molecular weights.

What are the four major tissue types that are found in animals?

Connective, muscular, epithelial, nervous

What four features are shared by all cells?

DNA, cytoplasm, cell membrane, ribosomes

What is a protoplast?

Everything inside the plasma membrane

Enzymes are consumed in chemical reactions and must therefore be replenished.

False

If using a monocular microscope, one eye should be kept shut while the other eye looks through the single ocular lens.

False

Oxygen is a product of the electron transport chain.

False

Protists are prokaryotes.

False

Specimens examined via a wet mount are typically not alive.

False

The active site is located on the substrate

False

As you move from low to high power magnification, which features of the microscope might you need to adjust? Check all that apply.

Fine focus adjustment knob Iris diaphragm

How do the products of glycolysis and the Krebs cycle relate to the electron transport chain?

Glycolysis and the Krebs cycle produce the molecules that shuttle electrons to the electron transport chain.

You and your classmates have been charged with preparing a wet mount in which you expect to see living Amoeba. As you search your slide for the temporarily elusive Amoeba, your lab partner exclaims "Eureka! I have found the perfect Amoeba on my slide!" She permits you to have a look at her slide, and you see she has clearly focused in on a perfectly round object with thick, dark edges. What should you say to your lab partner?

Good try, but objects with thick, dark edges that are perfectly round are usually air bubbles.

The oxygen produced by a plant comes most directly from

H2O.

In the middle of your thorough microscopic examination of Amoeba, your lab partner interrupts your careful study with a tap on your shoulder. He informs you that as he was looking through his microscope, as he adjusted the focus at high power, all of a sudden he saw strange, new lines running through his slide. He wonders if you can explain what has happened. What is the correct explanation?

He must have used the coarse focus in a downward direction and cracked the coverslip on his slide.

How can one best avoid the presence of air bubbles in a wet mount?

Hold the coverslip so it is just touching the edge of the drop of water, hold the coverslip at a 45 degree angle and then drop the coverslip onto the water.

Which of the following is not a role played by NADH in cellular respiration?

It oxidizes pyruvate.

Just imagine for a moment that NASA's Curiosity Rover that landed on Mars in the summer of 2012 finds evidence of life at the cellular level on Mars. Imagine that their initial observations show that this Martian cell has a nucleoid region and also a cell wall, and measures 7 microns in diameter. Conclude what you can about this cell. Check all that apply.

It shares characteristics with cells on Earth.

Which is not a protist?

Oscillatoria

Which does not represent a grouping of cyanobacteria?

Paramecium

In lab as you examine a variety of specimens, you will need to make a wet mount to complete your work. Which beings would best lend themselves to a wet mount that is to be viewed through the compound light microscope? Check all that apply.

Pond algae A small plant leaf

You are working in a real lab setting, and when you test the catalase and water together you see a reaction. What does this tell you? (Select all that apply.)

Possible contaminant in the water causing a reaction. You must complete the experiment again to verify your results.

Imagine that a cell was subject to a mutation that caused the loss of ribosomes. What would be the most immediate effect of this mutation?

Protein would not be synthesized.

As you are examining a Paramecium through the microscope, your lab partner expresses frustration as she keeps losing her specimen as she moves to high power. What would be a helpful suggestion that you might offer her?

She needs to switch back to a lower power objective, move her slide so the specimen is in the middle of the field of view, and then move to the higher power objective.

Given what you know about the function of mitochondria, in which type of tissue would you expect mitochondria to be particularly abundant?

Skeletal muscles

A student set up two test tubes containing Elodea plants and sodium bicarbonate and topped each of them with a volumeter. Tube A was wrapped in aluminum foil. Both tubes were placed in a test tube rack in front of a lamp containing a bright white bulb. The student obtained the following data from her experiment. Which of the following statements could explain this data?

The student did not turn the light on until after 10 minutes had already passed.

To combat a bacterial infection, a student receives a very necessary prescription for an antibiotic. Importantly the antibiotic kills the infective bacteria, so the student recovers from the infection. As an unintentional consequence, taking the antibiotic kills resident bacteria in his intestine, including lactobacilli. What may be an effect of killing the lactobacilli?

The student may suffer from gastrointestinal upset, especially after consuming dairy products.

When testing the temperature of catalase, what would happen if you changed the temperature using the same tube with the same catalase and hydrogen oxide mixture?

The substrate and enzyme would bind and react before all temperatures could be tested.

Which of the following statements about enzymes is FALSE?

The substrate binds to the enzyme with low specificity.

Based on your results from the enzyme concentration lab and the results table below, what might be happening to produce this data?

The substrate has been consumed in the reaction.

Enzymes have which of the following characteristics? (Select all that apply)

They are proteins. They can bind with substrate. They act as catalysts.

Most biologists agree that the most important metabolic pathway of living organisms is photosynthesis because its products directly or indirectly affect most living organisms.

True

Temperature, pH, and ionic concentrations play an important role in the proper functioning of enzymes.

True

A student set up an experiment to show the effect of light color on photosynthesis in Elodea plants. She filled three test tubes with distilled water and placed a piece of Elodea in each of the tubes. She added a drop of phenol red, which turns red in a basic solution and yellow in an acidic solution. She blew in each tube to add carbon dioxide, which caused the distilled water to become more acidic so the phenol red turned yellow. She exposed Tube A to white light, Tube B to green light, and Tube C was wrapped in aluminum foil. Which of the tubes should she expect to turn red the fastest?

Tube A

A student set up an experiment to show that carbon dioxide is consumed by Elodea plants during photosynthesis. She filled two test tubes with distilled water and placed a piece of Elodea in each of the tubes. She added a drop of phenol red, which turns red in a basic solution and yellow in an acidic solution. She blew in each tube to add carbon dioxide, which caused the distilled water to become more acidic so the phenol red turned yellow. She wrapped Tube A in aluminum foil and left Tube B exposed to the light. After 15 minutes, what should she expect to observe?

Tube A will be yellow and Tube B will be red.

A student set up an experiment where pieces of Elodea plant were placed in different test tubes and sodium bicarbonate solution was added. One of the tubes was wrapped in aluminum foil before both tubes were placed in front of a bright white light. Volumeters were placed on top and the volume was read every 10 minutes for 30 minutes. The results can be seen in the table below. Which of the tubes was exposed to light and how can you tell?

Volumeter B was in the light. The level of liquid in the volumeter went up because the plant was producing oxygen during photosynthesis.

Why would you not use green light and white light if you wanted to determine the dependence of specific color wavelengths on the rate of photosynthesis?

White light contains all visible wavelengths, not just one color.

Which would contain lactobacilli?

Yogurt

Under what environmental conditions do yeast carry out fermentation?

absence of oxygen

The main products of yeast fermentation are (Check all that apply)

alcohol CO2 NAD+

In the absence of oxygen, what anaerobic pathways can occur after glycolysis? (Check all that apply.)

alcohol Fermentation lactate Fermentation

Enzymes (Select all that apply)

are specific for their substrates. act as catalysts. have a special shape that controls their function. control the speed of reactions.

What is another name for cyanobacteria?

blue green algae

Of the visible light spectrum, the rate of photosynthesis is greatest under

blue light.

Enzyme activity can be determined in the following ways:

by measuring how much of the substrate is consumed by measuring how much of the product is produced

Which outer structure explains the difference in shape between plant and animal cells?

cell wall

The molecule that traps the sun's energy is

chlorophyll.

What cell structures and pigments are involved in photosynthesis? (Check all that apply).

chloroplasts fluid-filled stroma thylakoids chlorophyll A chlorophyll B carotenoids

The study of cell structure is known as _________.

cytology

In paper chromatography, photosynthetic pigments from a plant pigment extract will separate due to their (Check all that apply)

differences in solubility in a chromatography transport solution (mobile phase). differences in affinity for the chromatography paper (stationary phase).

Photosynthesis is

divided into two major steps, light dependent reactions and light independent reactions.

Without undergoing any changes itself, the _____ makes changes to the ______.

enzyme; substrate

A new plant species has a unique photosynthetic pigment. The leaves of this plant appear to be blue-green. What wavelengths of visible light does this pigment reflect?

green and blue

Of the visible light spectrum, the rate of photosynthesis is worst under

green light.

Based on your results from the enzyme concentration lab, when would increasing the enzyme concentration have no effect on the reaction rate?

if the majority of the substrate has been consumed in the reaction

Sports physiologists at an Olympic training center wanted to monitor athletes to determine at what point their muscles were functioning anaerobically. They could do this by checking for the buildup of which molecule?

lactate

Select all of the following that are true statements about fermentation.

lactate may be produced ethanol may be produced the reactions happen in the cytoplasm CO2 is produced

Photosynthesis takes place in the plant's

leaves and green stems.

How often can a catalase molecule be used to hydrolyze hydrogen peroxide?

many times

Cellular respiration

oxidizes glucose and reduces oxygen.

What may affect the rate of an enzyme-driven reaction? (Select all that apply.)

pH temperature concentration of enzyme concentration of substrate

Which of the following is not a reaction that cells use to get energy from nutrients?

photosynthesis

Altering the three-dimensional structure of an enzyme might

prevent the substrate from binding the enzyme's active site.

Yeast cells under anaerobic conditions

produce ethyl alcohol (ethanol).

The two data curves on the figure illustrate that

temperature ranges are not the same for all enzyme activity.

What information did the movement of the bubble over a specified distance in the calibrated respirometer provide? (Check all that apply)

the rate of cellular respiration the volume of oxygen used

During the experiment measuring energy production in plants, the highest rate of cellular respiration occurred in

the tube containing germinating seeds.

How does a phenol red-containing solution look if CO2 level is high?

yellow