Presentations

Gravitropism

Source: Sarah Wyatt, Ohio University   Format: Microsoft PowerPoint
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Description: This presentation covers the topics of gravitropism and signal transduction in plants, including an in-depth treatment of the current theories, historical evidence, and recent data regarding plant gravitropism. The PowerPoint file contains 40+ slides with lecture notes contained in the notes field. (Posted on 11/03)

Still Images

3-D Reconstruction of the Inner Ear
Source: NASA
Format: JPEG
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Description: This image shows computer-generated reconstructions of microscopic structures of the inner ear. (Posted on 10/00)

Cell Apoptosis
Source: NASA
Format: JPEG
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Description: Cell dying through apoptosis, or cell suicide, undergoes distinctive changes. First it shrinks and pulls away from its neighbors (top right). Then blebs (pink spheres) appear on the surface (making the cell appear to boil), and the chromatin (black portion of larger inner cell), which is the nuclear DNA complexed with proteins) condenses at the edges of the nucleus. Soon the nucleus, and then the cell itself, breaks up, and the cell fragments are quickly ingested by other cells in the vicinity. (Posted on 10/00)

Cell Division: Metaphase
Source: NASA
Format: JPEG
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Description: This image depicts a cell in mid-prometaphase. In this cell the spindle is forming between the well-separated centrosomes. Some of the chromosomes have established connections to both poles and are aligned at the spindle equator, while others are still connected only to one pole. (Posted on 10/00)

Cell Membrane Transfer
Source: NASA
Format: GIF
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Description: This line drawing depicts the components of a cell membrane. (Posted on 10/00)

Inner Ear
Source: NASA
Format: JPEG
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Description: This image shows the cochlea and the semi-circular canals of the inner ear. (Posted on 10/00)

Jellyfish Ephyra
Source: NASA
Format: JPEG
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Description: This photograph of a jellyfish ephyra shows the organism's gravity-sensing rhopalia. (Posted on 10/00)

Mammalian Vestibular Organs
Source: NASA
Format: PDF
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Description: The vestibular organs are the primary gravity sensing apparatus in mammalian species. (Posted on 06/01)

Rodent Otoliths
Source: NASA
Format: JPEG
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Description: This electron micrograph shows the otoliths found in the rodent ear. (Posted on 10/00)