Page 14 - ตัวอย่าง Science Solution 1

Kids Need
TO KNOW

In 1932, two German scientists named
Max Knoll and Ernst Ruska invented an electron
microscope that enabled observations on small objects.
Later in 1950, the electron microscope was enhanced
to enable observations on objects that are as small as
0.0005 micrometres and smaller details of the objects
within a cell. Modern electron microscopes have up to
500,000 times of magnifying powers.

Electron microscopes consist of similar
components to those of most compound light
microscopes, which are illuminators, burning lenses,
objective lenses and eyepiece lenses, but use
electron tubes that generate invisible light instead
of normal visible light and electromagnetic lenses
instead of glass lenses in compound light
microscopes.
Figure 1.21 Electron Microscope

1.3 Structures and Functions of Plant and Animal Cells

As we have learned that there are various types of
organisms that are different in sizes, shapes and characteristics, where the
organisms are plants or animals, they all consist of small cells
inside. Do you think plant and animal cells have identical shapes and
characteristics and why?

1.5 Comparing Plant and Animal Cells

Equipment

1. 1 compound light microscope
2. 2 sets of slides and cover slips
3. 1 razor blade
4. 1 toothpick
5. Red onion epidermal cells
6. Human Cheek Epithelial Cells How are plant and animal
3
7. 1 cm of methylene blue cells different from each
3
8. 1 cm of iodine other and why?

Unit 1 Units of Organisms and Plants Life 21