Opening Activity: April 26, 2018 New unit for our notebook! Clean page make a title on very top of page: Gene Regulation Make space for 10 days of opening activities. Have your initial ideas ready to stamp. If you have not done this – DO IT NOW!!!! I can… How does outside environment impact an organism’s well-being? Homework: Finish Lab #17 Questions if not done in class.

Development Test Retake is up to 23/27. Out of 27 pts - I took off one question that was a repeat (Test A #2 and #6 on Test B) so out of 27 pts. 24.5-28 A 21.5-24 B 19-21 C Retake is up to 23/27. If you want to retake the test you MUST turn in a retake ticket by Monday 4/30. No ticket = no retake! Retake will be Friday May 4th IN CLASS

Initial ideas What happens when a person tans? Share ideas at your table. What molecules are involved? What genes might be involved? Come up with ONE idea and ONE question – write on a sticky note and prepare to share

Today’s question: How do organisms respond to their environment? Today’s scale: macroscopic, atomic- molecular Help us answer: How is the sun changing/damaging the cells?

Maintaining Homeostasis How can the environment outside an organism impact an organism’s wellbeing? INITIAL IDEAS: (DO NOT TRY THIS AT HOME!) If a person drinks a large glass of very salty water, shortly after they will have diarrhea. Why do you think that is?

LAB Set up Please draw the following: Salt Water Water

Average percent change Data Table   Initial Mass Final Mass Change in mass Percent change Average percent change Your Data Class data

Gathering Data Wipe off the outside of your cell. Record the mass of your cell (Final Mass) Calculate the Change in mass. Calculate the Percent Change: Change in Mass X 100 Initial Mass Record data in computer. Turn in Dialysis Cell to Desler. Rinse out your Beaker several times with water. Complete your Questions!

Procedure 1. Hold tube between thumb and forefinger, and rub to separate and open tube. Tie one end of the tube closed 2. Fill the bag with up to 10 mL salt water solution using a pipette. 3. Leave a small amount of air at the top of the bag, tie the other end of the bag securely, with a double knot 4. Rinse the outside of the cell of carefully! 5. Record the Mass of the Cell (Initial Mass) 6. Put the cell filled with the solution in a glass of water. Wait 20 minutes 7. Reading & Questions while you wait.

When you have your set up complete: READ the handout about homeostasis. Underline and highlight key ideas. Answer the questions following the reading. Answer the analysis questions 1-3 If the above is not complete – HOMEWORK!!!!

Opening Activity: April 27, 2018 I will stamp HW: Reading Questions and Analysis Questions complete – DO IT NOW! What is the difference between a positive and negative feedback loop? Apples ripen on a tree due to a ripening hormone. Once ripe fruit gives off the hormone to promote ripening of fruit. Soon all the fruit are ripe or over ripe. What type of feedback? I can… Use data to explain phenomena. Take initial data of worms Homework: Complete Lab #18 C. Elegans Prediction on high salt plates.

Average percent change Data Table   Initial Mass Final Mass Change in mass Percent change Average percent change Your Data Class data

Final Results Record the mass of your cell (Final Mass) Calculate the Change in mass. Calculate the Percent Change: Change in Mass X 100 Initial Mass Record data in computer.

Revisit LAB Set up Label the inside of the dialysis tube with what it represents (What part of your body) Label the outside of the dialysis tube with what it represents (What part of your body) Salt Water Water

Tasks for the next 8 min: Revisit Initial Question: Why would drinking salt water lead to diarrhea? Use data to explain your reasoning!!! Get stamp for your explanation Pick up Lab #18 sheet and DATA COLLECTION sheet- tape into journal. Read through DAY 0 – what will we do today? 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!

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

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.

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

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

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.

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.

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

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 0) Questions 1-6 on Day 0 from lab sheet Prediction tool – HOMEWORK