1. April 7, 2009 Science 7ANNOUNCEMENT: Photosynthesis & Resp. QUIZ RE-TAKES Photosynthesis & Resp. QUIZ RE-TAKES Next Monday & Tuesday during ELO Next Monday & Tuesday during ELO Possibility to raise an I  C, or a C  B. Possibility to raise an I  C, or a C  B. You must be prepared to answer random questions correctly in conversation (oral quiz) You must be prepared to answer random questions correctly in conversation (oral quiz)

2. 4-7-09 ~ POD Watch a review video http://streaming.discoveryeducation.com/ –“Introducing the Cell” 15 min –Expectations? Discuss QUIZ on Thurs/Fri Onion and Cheek Cell LAB! –Analysis Questions

3. Questions from the video 1.Why is it important to learn about cells? 2.What are 3 main differences between plant and animal cells? 3.Why is the vacuole so big in plant cells? 4.What is the importance of the cell wall? 5.Why do muscle cells have more mitochondria? 6.What do you need to study for the quiz?

4. How to make a wet-mount slide … 1 – Get a clean slide and coverslip from your teacher. Careful of glass! 2 – Place ONE tiny drop of (iodine) in the middle of the slide. Don’t use too much or the water will run off the edge and make a mess! 3 – Place the edge of the cover slip on one side of the water drop. You do not need to use the stage clips when viewing wet-mount slides! 5 – Place the slide on the stage and view it first with the lowest magnification. Once you see the image, you can rotate the nosepiece to view the slide with the higher powered lenses. 4 - Slowly lower the cover slip on top of the drop. Cover Slip Lower slowly * 45 degree angle

5. Onion cell

6. Cheek cell

7. Onion and Cheek Cell Lab What you will turn in at end of class: Drawings Analysis Questions

8. Onion & Cheek Cell LAB Part 1: Cheek Cell 1.Place a tiny drop of iodine onto clean slide 2.Use a toothpick to scrape inside of mouth (cheek) 3.Make a zig zag onto iodine droplet. 4.Don’t use stage clips 5.View on Low Power (4x) 6.Draw what you see on Figure 1 7.View on High Power (10x) 8.Draw what you see on Figure 2 1.Draw 2 or 3 cells 2.LABEL: Nucleus, cell membrane, and cytoplasm 3.Use straight lines that do not intersect

9. Part 2: Onion Cell 1.Peel a thin layer of onion with forceps 2.Place the layer on the slide without folds (throw away remaining onion piece) 3.Place 1 tiny of brom. blue on onion layer 4.Cover with cover slip 5.View under low power (4x) 6.Draw what you see in Figure 3 7.View under high power (10x) 8.Draw what you see in Figure 4 1.LABEL: nucleus, cell wall, cell membrane, and cytoplasm 2.Use straight lines that do not intersect

10. What you don’t finish in class… Becomes HOMEWORK NUMBER off groups (3 per group) 1.Get microscopes 2.Get slide and slip cover 3.Directions, time keeper ALL: Help with cleaning up

11. Clean Up Process Please help! Clean as you go… Don’t drop the glass slides!!! Re-use your slide and slipcover for cheek and onion When finished: Group Roles 1.Gently place glass slides in soapy bowl 2.Place plastic slipcover in different soapy dish 3.Put microscopes away

12. Extensions… See me about looking at prepared slides of little creatures! OR… view random items under microscope such as: –Piece of hair; especially split ends –Paper towel –Piece of pasta Draw them in the extra circles (label the picture and note the power of magnification)