Introduction to Wisconsin Fast Plants® Phenotypes
Life Science—Mendelian Genetics, Variation of Traits. Recommended for grades 9-12.
Teacher Prep: 30 min (Note: Seeds take 2 to 3 days to germinate.)
Student Activity: 30 min for germination setup on day 1; 10 min for days 2 to 4 for observation; 30 min on day 5 for observation and conclusions
Safety Goggles Recommended
ViewEssential Question
What are the typical variations in traits, or phenotypes, found in Wisconsin Fast Plants®?
Investigation Objectives
- Observe differences in phenotypes in Wisconsin Fast Plants®.
- Predict the possible phenotypes resulting from various parent crosses.
Next Generation Science Standards* (NGSS)
Science and Engineering Practices
Developing and Using Models
- Students will develop a model of variation in traits for Wisconsin Fast Plants®. They will use their model to predict the phenotypes of F1 generation plants.
Disciplinary Core Ideas
LS3: Heredity: Inheritance and Variation of Traits
- LS3.B: Variation of traits among Wisconsin Fast Plants® will be determined through seed germination investigations.
Crosscutting Concepts
Patterns
- Observed patterns of traits in Wisconsin Fast Plants® guide organization and classification of trait variation. Relationships among inherited traits can be traced.
Safety & Disposal
Ensure that students understand and adhere to safe laboratory practices when performing any activity in the classroom or lab. Use personal protective equipment such as safety glasses or goggles, gloves, and aprons when appropriate. Require students to adhere to all laboratory safety rules.
Dry plants out completely, place them in a resealable bag, and dispose of them in the trash. Plants may be allowed to continue to grow for additional investigations.
Procedures
If using paper towels instead of filter paper, cut circles to fit the bottom of the petri dishes.
Fill spray bottles for watering.
- Place a filter paper or paper towel disk in the bottom of a petri dish. The paper should cover the bottom.
- If you are using paper towels, cut them into disks to fit the bottom of the petri dishes prior to the activity. If the paper towels are thin, 2 layers may be necessary to keep the seeds moist.
- Space the 10 seeds out evenly on the filter paper.
- To save time, count out 10 seeds for each student or group before the activity.
- Use the spray bottle to moisten the seeds and paper. The paper should be damp, but not sitting in a puddle.
- Check the petri dishes. Make sure seeds are separated and moist, but not standing in water.
- Cover the petri dish and place it under a flexible lamp or plant light bank.
- Place all seeds under intense fluorescent light for the duration of the investigation.
- Observe the seeds daily for 4 or 5 days, or as directed by your teacher. Record your observations on the data sheet.
- Seeds should germinate in 2 to 3 days.
- Use the spray bottle to mist the seeds as needed. They should be kept moist, but not wet.
- Remind students to observe the seedlings carefully. They need to look at stem and leaf color. Color may change in intensity over time.
Data
Record the number of seeds germinated each day for 4 or 5 days, or as your teacher instructs. Identify the color of the stem and the color of the leaves for each seed germinated.
Data will vary by group depending on the mixture of seeds they selected.
Analysis & Discussion
-
What are the 2 possible stem phenotypes?
Purple, hairy
Non-purple, hairless -
What are the 2 possible leaf phenotypes?
Yellow-green leaves and green leaves
-
Given your data, which phenotype appears to be dominant? Why?
Answers may vary depending on data, but purple, hairy is the dominant stem color and green leaf is the dominant leaf color.
-
How could you determine if a phenotype is inherited?
Cross a green stem plant with another green stem plant. Harvest and plant the seeds. If the plants that grow from the seeds have green stems, the phenotype is inherited. If some plants have purple stems, the green stem phenotype may not be inherited, and more study is needed.
-
Using the genotypes provided by your teacher, perform a dihybrid homozygous cross for purple stem color and green leaves with green stem color and yellow-green leaves. What are the phenotypes of the F1 generation?
F1 are all purple stem and green leaf, heterozygous.
ANL-YGR/ANL-YGR × anl-ygr/anl-ygr
*Next Generation Science Standards® is a registered trademark of Achieve. Neither Achieve nor the lead states and partners that developed the Next Generation Science Standards were involved in the production of, and do not endorse, these products.
Twitter
Facebook
YouTube
