density

(noun)

A measure of the amount of matter contained by a given volume.

Related Terms

Examples of density in the following topics:

  • Gas Vesicles

    • Gas vesicles are spindle-shaped structures that provide buoyancy to cells by decreasing their overall cell density.
    • Gas vesicles are spindle-shaped structures found in some planktonic bacteria that provides buoyancy to these cells by decreasing their overall cell density .
    • Gas vesicles provide bouyancy for some planktonic bacteria by decreasing their overall cell density.

  • Oligotrophs

    • Oligotrophs are characterized by slow growth, low rates of metabolism, and generally low population density.
    • Oligotrophs are characterized by slow growth, low rates of metabolism, and generally low population density.

  • Quorum Sensing

    • Quorum sensing is a system of stimulus and response correlated to population density.
    • Quorum sensing is a system of stimulus and response correlated to population density.
    • Many species of bacteria use quorum sensing to coordinate gene expression according to the density of their local population.
    • Bacteria use quorum sensing to coordinate certain behaviors based on the local density of the bacterial population .

  • Viral Roles in Ecosystems

    • As a rule of thumb, many phage biologists expect that phage population densities will exceed bacterial densities by a ratio of 10:1 or more (VBR or virus-to-bacterium ratio).

  • X-Ray Diffraction Analysis

    • The analysis consists of indexing, merging, and phasing variations in electron density.
    • The two-dimensional images taken at different rotations are converted into a three-dimensional model of the density of electrons within the crystal using the mathematical method of Fourier transforms, combined with chemical data known for the sample.

  • Sea Coral and Sea Anemone Zooxanthellae

    • In hosts, they usually occur in high densities, ranging from hundreds of thousands to millions per square centimeter.

  • Phase-Contrast Microscopy

    • In phase-contrast microscopy, parallel beams of light are passed through objects of different densities.

  • Planktonic Food Webs

    • Fish rely on the density and distribution of zooplankton to match that of new larvae, which can otherwise starve.

  • Genetic Analysis

    • PCR products of every gene from a complete genome sequence are bound in a high-density array on a glass slide.

  • Measurements of Microbial Mass

    • In spectrophotometry, cultures usually do not need to be diluted, although above a certain cell density the results lose reliability.