AP Biology Lab Review 1-4

Preview:

Citation preview

AP Biology

AP Biology Lab ReviewFred and Theresa HoltzclawWebb School of Knoxville

Using Figures from The LabBench by Theresa Knapp Holtzclaw

Modified from work by Kim Foglia

AP Biology

Lab 1: Diffusion & OsmosisFactors that affect diffusion across the membrane

AP Biology

Lab 1: Diffusion & Osmosis Description

dialysis tubing filled with starch-glucose solution in beaker filled with IKI solution

dialysis bags in different molarities

potato cores in sucrose solutions

AP Biology

Lab 1: Diffusion & Osmosis Concepts

semi-permeable membrane diffusion osmosis solutions

hypotonic hypertonic isotonic

water potential

AP Biology

Lab 1: Diffusion & Osmosis Conclusions

water moves from high concentration of water (hypotonic=low solute) to low concentration of water (hypertonic=high solute)

solute concentration & size of molecule affect movement through semi-permeable membrane

AP Biology

Water potential and water movementKnow how water potential is measured and relationship to solute concentration and pressure potential

water moves from a region of high water potential to a region of low water potential

What are the 2 components of water potential?

AP Biology

Calculating Water PotentialWater potential is calculated using the following

formula:

Water potential ( ) = pressure potential ( ) + solute potential( )

Pure water at atmospheric pressure has a solute potential of zero.

As solute is added, the value for solute potential becomes more ________ and water potential _____.

AP Biology

Know the relationship of molarity to osmotic concentration

AP Biology

1. In beaker B, what is the water potential of the distilled water in the beaker, and of the beet core?

a. Water potential in the beaker = 0, water potential in the beet core = 0b. Water potential in the beaker = 0, water potential in the beet core = -0.2c. Water potential in the beaker = 0, water potential in the beet core = 0.2d. Water potential in the beaker cannot be calculated, water potential in the beet core = 0.2e. Water potential in the beaker cannot be calculated, water potential in the beet core = -0.2

AP Biology

2. Which of the following statements is true for the diagrams?

a.The beet core in beaker A is at equilibrium with the surrounding water.

b.The beet core in beaker B will lose water to the surrounding environment.

c.The beet core in beaker B would be more turgid than the beet core in beaker A.

d.The beet core in beaker A is likely to gain so much water that its cells will rupture.

e.The cells in beet core B are likely to undergo plasmolysis.

AP Biology

Lab 1: Diffusion & OsmosisESSAY 1992A laboratory assistant prepared solutions of 0.8 M, 0.6 M, 0.4 M, and 0.2 M sucrose, but forgot to label them. After realizing the error, the assistant randomly labeled the flasks containing these four unknown solutions as flask A, flask B, flask C, and flask D.

Design an experiment, based on the principles of diffusion and osmosis, that the assistant could use to determine which of the flasks contains each of the four unknown solutions.

Include in your answer:a. a description of how you would set up and perform the experiment;b. the results you would expect from your experiment; andc. an explanation of those results based on the principles involved.

Be sure to clearly state the principles addressed in your discussion.

AP Biology

Lab 2: Enzyme CatalysisWhat factors affect the rate of an enzyme reaction?

Description measured factors affecting enzyme

activity H2O2 H2O + O2

measured rate of O2 production

catalase

Name an enzyme, substrate, products

AP Biology

AP Biology

Lab 2: Enzyme CatalysisHow can the structure of an enzyme be altered? Concepts

substrate enzyme

enzyme structure product denaturation of protein experimental design

rate of reactivity reaction with enzyme vs. reaction without

enzyme optimum pH or temperature

test at various pH or temperature values

AP Biology

Lab 2: Enzyme CatalysisBe able to calculate the rate of a reax

AP Biology

Lab 2: Enzyme Catalysis Conclusions

enzyme reaction rate is affected by: pH temperature substrate concentration enzyme concentration

calculate rate?

AP Biology

1. In order to keep the rate of reaction constant over the entire time course, which of the following should be done?

a. Add more enzyme

b. Gradually increase the temperature after 60 seconds

c. Add More substrate

d. Add H2SO4 after 60 seconds.

e. Remove the accumulating product

Lab 2: Enzyme Catalysis

AP Biology

2. What is the role of sulfuric acid (H2SO4) in this experiment?

a.It is the substrate on which catalase acts.

b.It binds with the remaining hydrogen peroxide during titration.

c.It accelerates the reaction between enzyme and substrate

d.It blocks the active site of the enzyme.

e.It denatures the enzyme by altering the active site.

Lab 2: Enzyme Catalysis

AP Biology

3. A student was performing a titration for this laboratory, and accidentally exceeded the endpoint. What would be the best step to obtain good data for this point?

a.Estimate the amount of KMnO4 that was in excess, and subtract this from the result.

b.Repeat the titration using the reserved remaining sample.

c.Obtain data for this point from another lab group.

d.Prepare a graph of the data without this point, and then read the estimated value from the graph.

Lab 2: Enzyme Catalysis

AP Biology

ESSAY 2000The effects of pH and temperature were studied for an enzyme-catalyzed reaction. The following results were obtained.

a. How do (1) temperature and (2) pH affect the activity of this enzyme? In your answer, include a discussion of the relationship between the structure and the function of this enzyme, as well as a discussion of ho structure and function of enzymes are affected by temperature and pH.

b. Describe a controlled experiment that could have produced the data shown for either temperature or pH. Be sure to state the hypothesis that was tested here.

Lab 2: Enzyme Catalysis

AP Biology

Lab 3: Mitosis Description

cell stages of mitosis exam slide of onion root tip count number of cells in each stage to

determine relative time spent in each stage

AP Biology

Lab 3: Mitosis Concepts

mitosis interphase prophase metaphase anaphase telophase

Conclusions Mitosis

cell division growth, repair making clones

longest phase = interphase each subsequent phase is

shorter in duration

I P M A T

AP Biology

The cell cycle

Know these:

MitosisCytokinesisCell Cycle1 hour

5-6 hours 10-12 hours

4-5 hours

AP Biology

Cytokinesis in animal cells

Compare and contrast plant and animal cytokinesis

AP Biology

Lab 3: Mitosis Know the events of mitosis and meiosis in plant and animal cells

AP Biology

Lab 3: Mitosis

AP Biology

Lab 3: Mitosis

AP Biology

AP Biology

Lab 3: Mitosis

AP Biology

Lab 3: Mitosis

AP Biology

Mitosis in a plant cell

Lab 3: Mitosis

AP Biology

Mitosis in an onion root

Know how to calculate the relative duration of each stage

AP Biology

The cell cycle in a certain cell type has a duration of 10 hours. The nuclei of 660 cells showed 33 cells in anaphase. What is the approximate duration of anaphase in these cells?

a.2 minutesb.10 minutesc.20 minutesd.30 minutese.600 minutes

Lab 3: Mitosis

AP Biology

Lab 3: Meiosis Stages Importance of Crossing Over

farther genes are from each other, the greater number of crossovers

AP Biology

Lab 3: Mitosis & Meiosis meiosis

meiosis 1 meiosis 2

crossing over Synapsis tetrads in prophase 1

AP Biology

Meiosis I

******Note that at the end of Meiosis I homologs have separated

AP Biology

Meiosis II

Now, what is separated in Meiosis II?

AP Biology

Meiosis

1. How many times is the DNA replicated?2. How many divisions?3. When is chromosome # reduced?

AP Biology

INDEPENDENT ASSORTMENT INTRODUCES VARIABILITY

AP Biology

CROSSING OVER INTRODUCES VARIABILITY

AP Biology

Points of Variability1. Independent assortment

How many different combinations of male/female chromosomes are possible in humans?

2. Crossing over

3. Random fertilization

and all of this variation is without mutation . . .

AP Biology

AP Biology

Lab 3: Meiosis in Sordaria Meiosis

4:4 arrangement in ascospores

no crossover any other arrangement

crossover 2:2:2:2 or 2:4:2

AP Biology

Sordaria analysis

% crossovertotal crossover

total offspring=

distance fromcentromere

% crossover

2=

AP Biology

Sordaria analysis

AP Biology

A group of asci formed from crossing light-spored Sordaria with dark-spored produced the following results:

Number of Asci Counted Spore Arrangement7 4 light/4 dark spores8 4 dark/4 light spores3 2 light/2 dark/2 light/2 dark spores4 2 dark/2 light/2 dark/2 light spores1 2 dark/4 light/2 dark spores2 2 light/4 dark/2 light spores

How many of these asci contain a spore arrangement that resulted from crossing over?

a.3 b.7 c.8 d.10 e.15

AP Biology

Lab 3: Mitosis & MeiosisESSAY 1987Discuss the process of cell division in animals. Include a description of mitosis and cytokinesis, and of the other phases of the cell cycle. Do not include meiosis.

ESSAY 2004Meiosis reduces chromosome number and rearranges genetic information.a. Explain how the reduction and rearrangement are accomplished in

meiosis.b. Several human disorders occur as a result of defects in the meiotic

process. Identify ONE such chromosomal abnormality; what effects does it have on the phenotype of people with the disorder? Describe how this abnormality could result from a defect in meiosis.

c. Production of offspring by parthenogenesis or cloning bypasses the typical meiotic process. Describe either parthenogenesis or cloning and compare the genomes of the offspring with those of the parents.

AP Biology

http://apcentral.collegeboard.com/apc/members/repository/ap04_sg_biology_37082.pdf

Link to rubric

AP Biology

Lab 4: Photosynthesis

AP Biology

Lab 4: Photosynthesis Description

determine rate of photosynthesis under different conditions light vs. dark boiled vs. unboiled chloroplasts chloroplasts vs. no chloroplasts

use DPIP in place of NADP+

DPIPox = blue DPIPred = clear

measure light transmittance paper chromatography to

separate plant pigments

AP Biology

Lab 4: Photosynthesis Concepts

photosynthesis Photosystem 1

NADPH chlorophylls & other

plant pigments chlorophyll a chlorophyll b xanthophylls carotenoids

experimental design control vs. experimental

AP Biology

Lab 4: Photosynthesis Conclusions

Pigments pigments move at different rates based on

solubility in solvent Photosynthesis

light & unboiled chloroplasts produced highest rate of photosynthesis

Which would be the control? DPIP + no chloroplasts

AP Biology

What is the Rf for chlorophyll a?

Lab 4: Photosynthesis

AP Biology

1. Which graph would be the most likely result of performing the photosynthesis experiment using fresh chloroplasts placed in light and DPIP?

2. What is the best explanation for graph B? a.The DPIP was too pale at the beginning of the experiment.b.The chloroplast solution was too concentrated.c.The experimenter used chloroplasts that were damaged and could not respond to light.d.The blank was not properly used to calibrate the spectrophotometer.

Lab 4: Photosynthesis

AP Biology

3. What effect would adding more DPIP to each experimental tube have on these results? a.Each curve would be shifted downward but would keep the same general shape.b.The curve in graph C would rise more steeply and level off sooner.c.The curve in graph A would have the same general shape as the curve in graph C.d.The chloroplasts would absorb more light energy, so there would be no change.

Lab 4: Photosynthesis

AP Biology

4. What is the role of DPIP in this experiment? a.It mimics the action of chlorophyll by absorbing light energy.b.It serves as an electron donor and blocks the formation of NADPH.c.It is an electron acceptor and is reduced by electrons from chlorophyll.d.It is bleached in the presence of light, and can be used to measure light levels.

Lab 4: Photosynthesis

AP Biology

5. Some students were not able to get many data points in this experiment because the solution went from blue to colorless in only 5 minutes for the unboiled chloroplasts exposed to light. What modification to the experiment do you think would be most likely to provide better results?

a.Increase the number of drops of chloroplasts used from 3 to 5.

b.Double the volume of DPIP so that the solution has a lower initial transmittance.

c.Modify the blank so that the initial transmittance is higher.

d.Use fresher spinach and prepare the chloroplast solution during the laboratory procedure.

e.Change the wavelength at which data is collected

Lab 4: Photosynthesis

AP Biology

Lab 4: PhotosynthesisESSAY 2004 (part 1)A controlled experiment was conducted to analyze the effects of darkness and boiling on the photosynthetic rate of incubated chloroplast suspensions. The dye reduction technique was used. Each chloroplast suspension was mixed with DPIP, an electron acceptor that changes from blue to clear when it is reduced. Each sample was placed individually in a spectrophotometer and the percent transmittance was recorded. The three samples used were prepared as follows.

Sample 1 — chloroplast suspension + DPIPSample 2 — chloroplast suspension surrounded by foil wrap to provide a

dark environment + DPIPSample 3 — chloroplast suspension that has been boiled + DPIP

Data are given in the table on the next page.

a. Construct and label a graph showing the results for the three samples.b. Identify and explain the control or controls for this experiment.c. The differences in the curves of the graphed data indicate that there were

differences in the number of electrons produced in the three samples during the experiment. Discuss how electrons are generated in photosynthesis and why the three samples gave different transmittance results.

AP Biology

Lab 4: PhotosynthesisESSAY 2004 (part 2)

Time (min)

Light, Unboiled % transmittance

Sample 1

Dark, Unboiled % transmittance

Sample 2

Light, Boiled % transmittance

Sample 3

0 28.8 29.2 28.8

5 48.7 30.1 29.2

10 57.8 31.2 29.4

15 62.5 32.4 28.7

20 66.7 31.8 28.5

Recommended