teaching the concepts of genetics

Teaching the Concepts of Genetics

Presented by: Keith MaddenAlvin EssenbergKasi BoldenSusan Rathwick

Drosophila Basic Studying the Monohybrid Cross

Cost: $87.95

Presented by Alvin Essenburg

Kit Includes

Anesthetizer Sorting brushes Culture containers Instant Drosophila medium Teacher's Notes

Supplies Needed: – Wild and Sepia Drosophila cultures (not part of

cost)– Disecting Scope (Magnifying glasses are difficult

to use)

Procedure

Step 1: Remove all Sepia adults from culture– Mature adult females can't be used because they

can store sperm for their entire life

Sepia

Procedure

2. When new fruit flies hatch in Sepia culture:– Remove all adults in Sepia culture within 6-8 hrs.– Sort and isolate females for 3-4 days in new

culture tube.

Sepia

Sepia females Sepia males

Sorting Male and Female

Procedure

3. Setup new culture tubes.– Place 5 Sepia female and 5 Wild males in each.

• (P generation)

Sepia Female Wild Sepia Female x Wild Male

Procedure

Flies will breed and lay eggs.

Sepia Female x Wild Male

Procedure

4. After 7-10 days, before new flies hatch, remove all adults.

Sepia Female x Wild Male

Procedure

5. New flies will be the F1 generation, remove adults within 6-8 hours and tally each species

• All will be Wild (Red eyes)

F1 generation

Procedure

6. As new F1 generation flies hatch, place 5 male and 5 female F1 in a new culture.

F1 generation

F1 x F1

Procedure

6. As new F1 generation flies hatch, place 5 male and 5 female F1 in a new culture.

F1 generation

F1 x F1

Procedure

7. Remove adults within 6-8 hours and tally each species

– New flies will be the F2 generation.

• About ¼ should hatch as Sepia

F1 x F1

Evaluation

Pros– Students get to actually do a monohybrid cross– High interest lab

Cons– Very time consuming and scheduled– Medium grew mold easily– May be difficult for students to sort flies at home– Could choose different varieties that can't fly

Protein SynthesisFlinn ScientificFB1760$46.30

Kasi L. BoldenWashington H.S.

Protein Synthesis

• Objective: The objective is to show how individual genes are translated into protein chains.

• Experiment overview: In this activity, models of mRNA, tRNA, amino acids and ribosomes will be used to better understand protein synthesis.

Teaching Tips• Students should know where transcription and translation

occurs.• Student should know that the triplet of bases brought by tRNA are

anticodons and is complementary to an mRNA codon.• Students should have a basic understanding of nucleic acids,

transcriptions and translation before beginning the activity.• A summary discussion after each step may be worthwhile to be

sure of students’ comprehension before moving on to the next step.

Materials

• Ribosome• mRNA strand• tRNA• Amino acid round chips, 20 (10)• Label, round 20(10)• Marker• Tape, double stick• Tape, transparent• *Protein Synthesis Worksheet( not provided)

Protein Synthesis Questionnaire

1. Does the lab present protein synthesis in the proper sequence so students will gain understanding?

Yes or No2.  Are there any materials that can be substituted or

eliminated?3.  Do you think the first and second steps of the procedure

are necessary?4. Do you feel it’s necessary to teach the importance of 3’ &

5’?5.  Please list any flaws in this activity. List any flaw that may

cause confusion

Analyzing Population Growth Kit

Carolina Item #251012 Price $99.95

Materials for 32 students working in groups of 4

Objectives/Learning Goals• Students analyze the effects of resources on

yeast as they explore population growth.

• Develop the skills necessary to design & perform scientific investigations

• Produce a testable hypothesis

• Investigate the effects of environmental conditions on a model lab species

Objectives/Learning Goals

• Derive the relationship between resource quality and population growth

• Develop connections with the key concepts of logistic and exponential growth, carrying capacity, and population pyramids

Objectives/Learning Goals

Materials Supplied• 32 petri dishes• Parafilm®• 4 yeast malt media bottles• 100 pipets (graduated)• 9 sterile pipets• 9 yeast packets• 18 g lactose

• 30 ml excess nitrate• 2 sheets black construction

paper• 8 fine-point permanent

markers• 8 inoculating loops• 40 test tubes• 16 Lazy-L-Spreaders™

Materials Not Supplied• Safety glasses• Heat-resistant gloves• 8 glass beakers, 400ml • 8 Bunsen burners• 8 flint lighters• 1 gallon distilled H2O

• 8 hot plates• 8 dissecting scopes• 8 thermometers• Laboratory balances• Weight boats 2 spatulas• 8 graduated cylinders, 100

ml• 8 flasks, 125 ml

Background Vocabulary• Age ratio• Carrying

capacity• Demographics• Emigration• Population

pyramid

• Exponential growth

• Immigration• Logistic growth• Population• resources

Lab Could Be Used During the Study of…..

• Interdependence of organisms• Behavior of organisms• Population growth• Natural resources• Environmental quality• Natural & human-induced hazards

Background Knowledge• Exponential growth – if a population is not limited by

resources, and increases at a faster rate as the number of individuals increases.

• Logistic growth - describes a growth rate that levels off and is maintained.

• Population pyramid – graph showing how the total population is split among various age brackets.

• Yeast- microscopic, unicellular fungi able to live with our without O2

• Plate streaking techniques

Activity #1• Requires students to fill 3 test tubes with yeast and

either glucose or lactose as a food source. Test tubes are covered and placed in a hot water bath 35-40° C.

• Students will record growth in 2 minute intervals for a total of 10 minutes

• A fourth tube is filled as a control group.• Results are shared among the teams

Activity #2• Requires students to choose 1 of four treatments they

hypothesize will produce the most growth in the yeast population

• Treatments• Glucose• Lactose• Nitrate• Light intensity

• Students are required to write their hypothesis and reasoning for this in their lab notebook

• Procedures are provided for each of the 4 treatments students will choose.

• After the plates are prepared they will invert and leave for three days

• After 3 days the groups will decide how to rate the growth in the petri dishes, writing down the comparative data in their lab notebook and creating a bar graph to display the data

• Students analyze the results

• Prior to Step 1 (follow the first step in Activity 1)

• Warm up a beaker of 40 mL distilled water to about 30-40°C.

• Remove from heat and add 3.5 g of yeast• Cover it with a 4-square block of Parafilm®• Let yeast activate for 10 minutes

Comparative Proteomics Kit I: Protein Profiler Module

Bio-Rad 166-2700EDU32 studentsList Price: $203.75Refill: $ 94.00

Comparative Proteomics Kit I: Protein Profiler ModuleLaemmli sample bufferKaleidoscope™ prestained standardsTris-glycine-SDS electrophoresis bufferBio-Safe™ Coomassie stain for proteinsActin and myosin standardDithiothreitol (DTT)Pipet tips for gel loadingTest tubes,transfer pipets, gel-staining trays,

test tube holdersTeacher's Guide, Student Manual, and graphic

Quick Guide

Required Accessories Not Included in KitFish samples 5–8 typesAdjustable micropipets, 2–20 µlPower suppliesWater bathIf using polyacrylamide gel

electrophoresis:Vertical gel electrophoresis chambersPrecast polyacrylamide gels

Is There Something Fishy About Teaching Evolution?

Can Biomolecular Evidence Be Used to Determine Evolutionary Relationships?

• Traits are the result of Structure and Function

• Proteins determine structure and function

• DNA codes for proteins that confer traits• DNA -> RNA -> Protein -> Trait

• Changes in DNA lead to proteins with:• Different functions• Novel traits• Positive, negative, or no effects

• Genetic diversity provides pool for natural selection = evolution

Explore Biochemical Evidence for Evolution• Analyze protein profiles from a variety of fish

• Study protein structure/function

• Use polyacrylamide electrophoresis to separate proteins by size

• Construct cladograms using data from students’ gel analysis

• Compare biochemical and phylogenetic relationships.

• Sufficient materials for 8 student workstations

• Can be completed in three 45 minute lab sessions

Workshop Timeline• Introduction

• Sample Preparation

• Load and electrophorese protein samples

• Compare protein profiles

• Construct cladograms

Sample PreparationLab Period 1

Label one 1.5 ml fliptop tube for each of five fish samples. Also label one screwcap micro tube for each fish sample.

Add 250 μl of Bio-Rad Laemmli sample buffer to each labeled fliptop microtube.

Cut a piece of each fish muscle about 0.25 x 0.25 x 0.25 cm3 and transfer each piece into a labeled fliptop tube. (Close the lid!)

Sample PreparationLab Period 1 (con’t)

Agitate the tissue in the sample buffer; Incubate for 5 minutes at room temperature.

Carefully transfer the buffer labeled screwcap tube. Do not transfer the fish!

Heat the fish samples in screwcap microtubes for 5 minutes at 95°C. Freeze until lab period 2.

ElectrophoresisLab Period 2Heat extracted fish samples and actin and

myosin standard to 95°C for 2–5 min. This dissolves any detergent in the extraction (Laemmli) buffer that may have precipitated upon freezing.

ElectrophoresisLab Period 2 (con’t)Load your gel:• 5 μl Precision Plus Protein Kaleidoscope

prestained standards (Stds)• 10 μl fish sample 1• 10 μl fish sample 2• 10 μl fish sample 3• 10 μl actin and myosin standard (AM)

ElectrophoresisLab Period 2 (con’t)Electrophorese for 30 minutes at 200 V in 1x

TGS electrophoresis buffer.After electrophoresis, stain the sample with 25

ml Bio-Safe Coomassie blue stain per gel.Stain gel for 1 hour, with gentle shaking for

best results.

ElectrophoresisLab Period 3Destain gels in water for at least 30 minutes

to overnight, changing the water at least once.

Blue-stained bands will be visible on a clear gel after destaining.

AnalysisLab Period 3 (con’t)Correlate bands of fish samples with AM and

Kaleidoscope standards.Check online protein database for correlation

of sample proteins with those of the species in the databases.

Guided by similarity of protein content, draw cladogram relating fish species.