1. KEY CONCEPT Technology continually changes the way biologists work.

2. SC.912.L.14.4 Compare and contrast structure and function of various types of microscopes. (MODERATE)

3. Light Microscope

4. Imaging technologies provide new views of life.
A microscope provides an enlarged image of an object.
Light microscopes (LM)
Light and lenses used to magnify specimens
limited magnification
can be used to study living specimens
shows a two-dimensional image of a specimen.
Shows actual color of the specimen.
stoma
This light microscope shows the actual color of the specimen. Guard cells surround=ding a stoma, or pore in a leaf.

5. Scanning Electron Microscopes

6. Imaging technologies provide new views of life.
Scanning electron microscopes (SEM)
Deflection of electrons used to magnify specimens; provides high magnification and a
three-dimensional black-and-white image that can be colored by computer
cannot be used to study living specimen
stoma
A SEM shows a three dimensional image of a specimen’s surface. A SEM is colorized by computer. The bottom part of the image shows the original black and white image.
SEM magnification 1500X

7. Transmission Electron Microscope

8. Imaging technologies provide new views of life.
Transmission electron microscopes (TEM)
Electrons passing through a specimen used to magnify specimen;
provides high magnification
two-dimensional black-and-white image that can be colored by computer
cannot be used to
study living specimens
stoma
A TEM shows a two –dimensional image of a thin slice of a specimen. A TEM is colorized by computer. The bottom part shows the original black-and-white image. TEM magnification 5000X
Electrons passing through a specimen used to magnify specimen; provides high
magnification and a two-dimensional black-and-white image that can be colored by
computer; cannot be used to study living specimens

9. Animated biology – look at the three types of microscopes.
Quick Lab- Life under a microscope.

10. Imaging technology is used in medicine.
X-ray images
X-rays passing through
tissues used to show
dense materials (bones,
teeth)

11. Imaging technology is used in medicine.
magnetic resonance imaging (MRI)
Magnetic field used to show all tissues, including soft tissues such as tendons and
ligaments
Magnetic field used to show all tissues, including soft tissues such as tendons and
ligaments

12. Imaging technology is used in medicine.
Functional MRI (fMRI)
Magnetic field that can be used to shown activity in particular brain regions while a subject is performing a task

13. Complex systems are modeled on computers.
Computer models are used to study systems that cannot be studied directly.
heart attacks
Normal heartbeat
effect of medicines on the human body
movement of water molecules into and out of a cell
spread of a disease through a population
Heart attack
Use of computers to simulate complex systems when actual experiments are not possible
Computer models are used when experiments are not safe, ethical, or practical.

14. The tools of molecular genetics give rise to new biological studies.
A gene is a segment of DNA that stores genetic information.

15. Study & manipulation of DNA at the molecular level
Through our understanding of DNA, we can study genetics on a molecular level.
molecular genetics
Study & manipulation of DNA at the molecular level
genomics
Study and manipulation of DNA at the molecular level