1. HW: Graphing Practice pg 11 - 14 in Review Packet
HW: Graphing Practice pg in Review Packet. DO NOT TAKE IT OUT OF THE REVIEW MANUAL. Extra help for DENSITY is available during lunch to get ready for the Lab Practical.
Do Now: /8/17
Hand in your Moon Webquest
Begin quietly working on the PreAssessment packet while you are given a Final Review Lab Manual

2. 7th Grade Science Lab Practical – Part 1 of the Final Exam
What types of science tools will I need to use correctly during the lab practical exam next week?
How can I prepare myself to earn the most points possible?
Microscope, Triple Beam Balance, and Ruler/Calculator
Practice using these tools accurately!

3. Lab Practical Skills “Pre-Assessment”
Grading
Switch papers with one of your lab partners. Use a colored pencil to grade their paper. This grade will not count towards your science average, but will be used to help you understand how you may have scored on the lab practical exam.

4. Answers:
What are the units for measuring mass on a triple beam balance? (1pt)
____________
If you went to mass a cube on a triple beam balance, and the diagram below is what you saw, what is the mass of that cube? (1pt)
___________________
grams
27.7g
**Graders: Take off ½ point for not including units!!
Range: 27.6g-27.8g

5. Graders: take off ½ point for no units. Range: 354.5g -354.7g
What is the mass of the rock? (to the nearest 0.1g) (1pt)
b) If the volume of the rock is 20cm3, what is the DENSITY of the rock? (1pt) SHOW ALL WORK IN THE BOX:
354.6g
Graders: take off ½ point for no units. Range: 17.0 g g
354.6g/20.0cm3 = 17.7g/cm3

6. Metric or mm side The field of view is the white circle you
1) Describe what the “field of view” is on a microscope. (1pt)
The field of view is the white circle you
see when you look through the eye piece of the microscope.
(1pt) What side of the ruler would you use to measure the field of view of the microscope?
Metric or mm side
3) A student calculated the diameter of the low-power field of a compound light microscope to be 4 millimeters. If 3 plant cells fit across the diameter (see picture on the side), what is the approximate size of each plant cell? (1pt)
Field of view = diameter
how many organisms can fit across
4.0 mm/3 = 1.3 mm  Rounds to 1.5mm
*Graders: accept answers from mm Take ½ point off for no units

7. 4) Base your answer on the diagram below
4) Base your answer on the diagram below. The field of view was measured by a student to be 4mm. They estimated that the size of the organism was 7.0 mm.
Does their answer make sense? (1pt) Explain below:
No. This student’s answer does not make sense at all. If the organism is 7.0 mm that would mean it would take up the entire field of view which according to this picture it does not. A more logical answer would be closer to mm.

8. Section III: Graphing
The Effect of Time on the Number of Living Bacteria at 25o C
200
190
180
170
160
150
140
130
120
110
100
Bacteria (Number Living)
Time (days)
As the number of days in the incubator increased, so did the number of living bacteria.

9. What will be on the Lab Practical Exam?
Three Timed Stations:
Microscope
Density
Graphing
Today we will practice for the Microscope and Density stations

10. Density Station
*Pages 2 – 5*

11. Calculating Density
Page 3 - 5

12. Triple Beam Balance Practice

13. Let’s read the Microscope Reminders on Page 6
together

14. The Microscope Eye piece Body Tube Nosepiece Arm Objective Objective
Can you name the parts of the Microscope? Close your binder No Peeking!
Eye piece
Body Tube
Nosepiece
Arm
Objective
Objective
Stage
Objective
Stage Clips
Course Adjustment
Diaphragm
Fine Adjustment
Light Source
Base

15. Estimating Specimen Size Page 71 2 3 4 5 6 7

16. 4.0mm÷5 = 0.8mm each (rounds to 1.0mm)
Example Problem: The diagram below shows the edge of a millimeter ruler viewed under the microscope. 1 2 3 4
What is the approximate width of the field of view in mm?
(include units!) ________
If 5 cells fit across the field of view, what is the size of each cell? (round to the nearest .5mm) ___________
4.0 mm
about 1.0 mm
4.0mm÷5 = 0.8mm each (rounds to 1.0mm)

17. turn it on!
millimeters
count the spaces
course adjustment knob
1.0 mm (if # across 3.5)
or 1.5 mm (if # across 3)
1.0 mm (if # across 3.5 or 4)

18. Microscope Station: Easy as 1, 2, 3
Using the prepared slides from your teacher, complete the following:
Determine the size of the field of view
MATERIALS: Clear Ruler (mm), Calculator, Microscope (4X)
Size = F.O.V / # that can fit across the diameter
2. Estimate the size of the prepared slides at your microscope station.
MATERIALS: 2 Prepared Slides, Microscope (4X)
Estimate how many of these objects could fit across the diameter
of the field of view. Record your answers onto page 10.
Check your answers with your teacher before moving on.
3. Continue practicing with additional slides until the end of the period.
Record your answers onto page 11. Check your answers with your
teacher before leaving class.
Additional time will be provided to practice microscope skills during your lunch period.

19. Interactive Microscope Practice
Visit your teacher’s blog to access this interactive Microscope practice site.