1. Opening Activity: April 24, 2017
Pick up Lab #18 & Worm Observation sheet– Tape both into journal (tape at R. Table)
Scientists often use “model organisms” in the lab to complete research studies. If you were doing research, what characteristics of the organism you were studying would help you in your work? List at least five characteristics!
I can… make observations and collect data using a model organism. make scientific predictions.
Homework:
Protein Synthesis Quiz 4/28
Retake for Enzyme/Protein Network Quiz Next week

2. Model Organisms
= living systems used to study biological processes. Many biological processes are nearly the same in all living things.

3. Model Organisms – C. elegans
They are very well-studied so there is already a wide body of knowledge about them.
They are small, transparent, reproduce quickly, and are relatively inexpensive to house.
Although simple looking, they have complex organ systems (digestive, excretory, reproductive, nervous, etc.) that have processes similar to those of humans.

4. Agar (nutrients for E. coli; salt)
Observing Worms
Agar (nutrients for E. coli; salt)
Worm
E. coli bacteria
(food for worms)

5. Life Cycle of C. elegans 55 hours = 2 days + 7 hours
Adults
( ~ 1 mm)
Egg L1 L3 L4
9 hours
12 hours
8 hours
18 hours
Lifecycle of C. elegans L2
55 hours =
2 days + 7 hours

6. Tips for Observing Worms
Store the plates with the agar side up so that condensation doesn’t drop onto the plate.
Flip the plate over to look at it under the microscope. You may need to remove the clear cover to see them well, but only leave the cover off for a few minutes.
Do not leave the worms on the microscope in the light for more than a few minutes, as they can get too hot.

7. Observing Worms eggs, larvae and adults worms responding to touch
Some things to look for:
What life stages are present (adult, larvae, egg)?
Where are worms on the plate (on agar, on food, near edge of plate)?
What are the worms doing (moving, not moving, feeding)?
Watch these videos showing…
eggs, larvae and adults
worms responding to touch

8. Observing Worms What life stages are present (adult, larvae, egg)?
Some things to look for:
What life stages are present (adult, larvae, egg)?
Where are worms on the plate (on agar, on food, near edge of plate)?
What are the worms doing (moving, not moving, feeding)?
Goals for today…
Complete top left worm observation (we will call day 1)
Questions 1-6 on Day 1 from lab sheet
Prediction tool

9. Observing Worms
Place a worm plate on the stage of the scope, agar side down. Take off the lid.
Find a place on the plate that has worms of different sizes.
Observe and sketch the worms in your journal. Draw with detail and to scale.
Complete the journal questions and clean up your lab space appropriately.
Complete the Predictions Tool for a STAMP tomorrow.

10. Opening Activity: April 25, 2017
What environmental changes might C. elegans experience during the day? How might the worms might respond?
What environmental changes do you experience during the day? How do you respond?
Complete Prediction Tool for Lab #19
I can… … investigate how organisms respond to environmental changes.
Homework:
Protein Synthesis Quiz 4/28
Retake for Enzyme/Protein Network Quiz - Next Week

11. Agar (nutrients for E. coli; salt)
Observing Worms
Agar (nutrients for E. coli; salt)
Worm
E. coli bacteria
(food for worms)

12. Transferring Worms by Chunking
Wild-Type (N2) worms on a plate
Cut agar into 2 pieces
Move one chunk to
LOW-SALT
plate
Move one chunk to HIGH-SALT plate
Wild
Low
High
Flip

13. C. elegans & the environment
Label a high salt plate and a low salt plate with your period and table name. (Label the BOTTOM plate)
These plates had worms “chunked” onto them about 15minutes ago.
Observe the worms on the high and low salt plates. Make detailed comparisons.
Complete the data table(s) and answer analysis questions.
Answer the Journal Questions – the Glycerol Reading is needed to answer many of the questions.

14. Class Data Table – Period 1
LOW Salt
HIGH Salt
Day 1
Day 2
Day 3
Day 6

15. Class Data Table – Period 2
LOW Salt
HIGH Salt
Day 1
Day 2
Day 3
Day 6

16. Opening Activity: April 26, 2017
Your worms have been in their low salt and high salt environments for 24 hours:
What do you predict you will observe when you look at the worms today?
Draw a labeled picture of what happens to the worm’s cells in a high salt environment.
I can… I can investigate how organisms respond to environmental changes.
Homework:
Protein Synthesis Quiz 4/28
Retake for Enzyme/Protein Network Quiz – Next week

17. C. elegans & the environment
Answer the Journal Questions – the Glycerol Reading is needed to answer many of the questions – you and your groups have 15 minutes to finish this together for a STAMP!

18. Environmental Responses
With your partner, use pictures, words, and arrows to explain how you think a C. elegans worm responds to high salt conditions
Use the checklist to make sure you have shown all of your ideas

19. Class Data Table – Period 1
LOW Salt
HIGH Salt
Day 0
Day 1
moving slowly
spread out
spread out/grouped together
not moving
shrunken
Day 2
Eggs – worms are reproducing
Worms got longer – they grew! So they ate. Digestion & biosynthesis.
Worms in the food.
More worms! Eggs, larvae, adults.
Moving slowly.
Some eggs, larvae – reproducing.
Not as large as the low salt (so they didn’t grow as much)
Spread out on the plate.
Day 5

20. Class Data Table – Period 2
LOW Salt
HIGH Salt
Day 0
Day 1
moving a lot
No eggs – larvae & adults
Moved away from the chunk
Moved towards the food
No movement
Grouped together (close to chunk)
No eggs- larvae & adults
Dead? Dried out? Dormant?
Day 2
More movement
Lots of eggs, lots of larvae – lots of reproduction
Bigger! Eating, growing (biosynthesis)
Mainly on the food, near the food, everywhere
Moving from chunk to food
Lots of adults and larvae, some eggs (not a lot)
Smaller than the worms on low salt (grew less? Grew slower?)
Moving more than yesterday – recovered?
Day 5

21. Class Data Table – Period 4
LOW Salt
HIGH Salt
Day 0
Day 1
Larvae & adults (lots), maybe some eggs?
Some groups of larvae
Everywhere on the plate, including food
Moving around, erratic
Hardly moving
Bunched up together
Maybe some larvae, lots of adults, not really eggs
Maybe some dead worms
Smaller? Shrunken?
More transparent
Not at food, on the chunk, near the chunk
Day 2
Eggs, larvae, and adults
Active, moving a lot
Everywhere, but a lot in the middle
moving slowly, but more than yesterday
Eggs (but less than on low salt), some adults, mostly larvae
Day 5

22. Class Data Table – Period 5
LOW Salt
HIGH Salt
Day 0
Day 1
Moving away from the chunk, in the food, all over the plate
Lots of movement
Adults (some), larvae, maybe eggs (very few)
Adults, larvae, no eggs
Not moving, maybe dead
Different color, darker, less transparent
Some in food, some near the chunk
Day 2
more eggs and adults than yesterday, larvae
In center of plate, near food
Moving slowly but faster than in high salt
eggs, larvae, and adults
In the middle, near the food, all around on some plates
Moving slowly, some moving at “normal” speed,
Day 5

23. Opening Activity: April 27, 2017 TBD
I can… I can investigate how organisms respond to environmental changes.
Homework:
Protein Synthesis Quiz 4/28
Retake for Enzyme/Protein Network Quiz – next week

24. Environmental Responses
With your partner, use pictures, words, and arrows to explain how you think a C. elegans worm responds to high salt conditions
Use the checklist to make sure you have shown all of your ideas

25. Environmental Responses - Feedback
Share your model with a partner group from another table. Have the partner group share their model as well.
Complete the feedback form and give it to the group you gave comments to.
Revise your model in a new color. Turn in the model with the feedback form stapled to it.

26. Worms and Glycerol Begin work on the Worms & Glycerol case study.
Work with your table group and get as far as you can. There will be some time to work on this on Tuesday – if you stay on task.