Transcript Sizing Up Cells - Cloudfront.net

Sizing Up Cells
A DataTools sample investigation
Key Parts of an Investigation
•
•
•
•
•
•
•
•
•
Question(s)
Goals
MA state frameworks
Overview & approximate time
Data and analysis tools
Main steps for analysis techniques
Background information
Sample product(s)
Student handouts for data collection &
analysis (if provided); may be electronic
Investigation Question(s)
• How big is a cell? Are all cells alike?
How do they compare in size, structure,
and function?
MA Science Framework
• Life Science: Grades 6 to 8
• Structure and Function of Cells
3. Compare and contrast plant and
animal cells, including major
organelles (cell membrane, cell
wall, nucleus, cytoplasm,
chloroplasts, mitochondria,
vacuoles).
Typical Cell Diagrams
Investigation Goals(s)
• Students will develop an appreciation
for the diversity and complexity of cells
in living things
• Students will recognize differences and
similarities in size, structure, and
function among cells
• Students will understand basic cell
structure and function
Overview & Time
• Students analyze digital images of cells,
measuring lengths of a variety of cells
• From 1 to 2 class periods up to a week
Data & Analysis Tools
• Images of cells with scale bars
• ImageJ
• Excel
Steps for Data Analysis
•
•
•
•
•
•
Set scale in ImageJ
Measure cell lengths with ImageJ
Chart average lengths in Excel
Scale images to show relative sizes
Copy & paste to compile a composite image
Going Further: Annotate Cell images
Background information
• http://en.wikibooks.org/wiki/Biology_Cell_
biology_Introduction_Cell_size
• http://simscience.org/membranes/advanced/
essay/cellsize1.html
Cell or Ce ll Part
anthrax b acteria
e.coli bacteria
mitochond ria
general s ize for prokaryotes
nucleus of human cheek cell
length of a chlorop last
human red blood cell
most Eukaryo tic anim al cells
human ch eek cell
most Eukaryo tic plant cells
small amoeba c ell
human egg cell
average amoeba cell
onion skin plant cell
large amoe ba cell
giant squid ner ve cell
spinal cord ner ve cell
diam eter of an ostrich egg
Length of a nerve ce ll of giraf fe's neck
Size
1 µm
2 to 10 µm
3 µm
1 to 10 µm
5 µm
5 µm
7.5 µm
10 - 30 µm
60 µm
10 - 100 µm
90 µm
100 µm
300 µm
400 µm
800 µm
1000 µm
600,000 µm
120 mm
3 meters
Cells vary in size, structure,
and function
Human blood cell
Human cheek cell