biologists’ tools and technology

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Biologists’ Tools and Technology Section 1.4

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Biologists’ Tools and Technology. Section 1.4. Compound Light Microscope. Compound light microscopes: Used to view living or preserved specimens Light passes through the specimen Stains are often used to view specimens Uses two lenses to magnify specimens - PowerPoint PPT Presentation

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Page 1: Biologists’ Tools and Technology

Biologists’ Tools and Technology

Section 1.4

Page 2: Biologists’ Tools and Technology

Compound Light Microscope

Compound light microscopes:• Used to view living or preserved

specimens• Light passes through the specimen• Stains are often used to view

specimens• Uses two lenses to magnify

specimens• Clearly magnifies up to 1500x actual

size

Page 3: Biologists’ Tools and Technology

Scanning Electron Microscope (SEM)

Scanning Electron Microscopes:• Scans the surface of a specimen with a beam

of electrons• Provides 3D images of specimens

Page 4: Biologists’ Tools and Technology

Transmission Electron Microscope (TEM)

Transmission Electron Microscopes:• Transmit electrons through a thin

slice of a specimen• Provides 2-D images of a

specimen • TEM’s cannot be used on living

specimens• Magnify up to 500,000X

Page 5: Biologists’ Tools and Technology

Let’s visit http://www.classzone.com to view images from a:• Compound Light Microscope• Transmission Electron Microscope (TEM)• Scanning Electron Microscope (SEM)

Page 6: Biologists’ Tools and Technology

Magnetic Resonance Imaging (MRI)

Magnetic Resonance Imaging (MRI):• Uses a strong magnetic field to produce

a cross-section image of a specific part of the body

• Is a good tool for viewing soft tissues (ligaments, cartilage, or the brain)

Page 7: Biologists’ Tools and Technology

X-RaysX-Rays:• Uses high energy

radiation to take pictures of dense tissue (bones)

• Cannot provide information about soft tissues (brain, cartilage or ligaments)

Page 8: Biologists’ Tools and Technology

Ultrasounds

Ultrasound:• Uses high-frequency sound waves that can be bounced off of tissues using special devices. The echoes are then converted into a picture called a sonogram. Ultrasound imaging, referred to as ultrasonography, allows physicians and patients to get an inside view of soft tissues and body cavities, without using invasive techniques.

Reference: www.medicinenet.com

Page 9: Biologists’ Tools and Technology

Computerized Tomography Scan(CT Scan)

CT Scans:• Form pictures of structures within the body created by a computer that takes the data from multiple X-ray images and turns them into pictures on a screen. • The CT scan can reveal some soft-tissue and other structures that cannot even be seen in conventional X-rays. Using the same dosage of radiation as that of an ordinary X-ray machine, an entire slice of the body can be made visible with about 100 times more clarity with the CT scan. Reference: www.medterms.com

Page 10: Biologists’ Tools and Technology

Computer ModelingComputer modeling has greatly expanded biological research. It allows for computer-aided simulations to be utilized in place of traditional experiments when experiments are not practical due to safety issues or ethical concerns. For example, computer models can be used to:

Study epidemiology (disease epidemics) Determine affects of new medicines and vaccines on the

human body Study molecular genetics (DNA sequencing)

Computer generated view of blood flow in the heart.

Heart Attack

Healthy Heart

Page 11: Biologists’ Tools and Technology

Molecular Genetics & GenomicsMolecular genetics is the study and manipulation of DNA on a molecular level. It is used to study:

Evolution Ecology Biochemistry Heredity

By combining molecular genetics and computer modeling every gene in the human body has been located and mapped out through the Human Genome Project.

Genomics is the study and comparison of genomes within and among species.