grey matter

Examples of grey matter in the following topics:

• Spinal Cord

  • Myelinated axons (the part of neurons that send signals) compose the "white matter," while neuron and glial cell bodies (neuronal "support" cells) compose the "grey matter."
  • Grey matter is also composed of interneurons, which connect two neurons, each located in different parts of the body.
  • A cross-section of the spinal cord shows grey matter (containing cell bodies and interneurons) and white matter (containing axons).

• The Periodic Table

  • Matter comprises all of the physical objects in the universe, those that take up space and have mass.
  • All matter is composed of atoms of one or more elements, pure substances with specific chemical and physical properties.
  • The elements at the boundary between the metallic elements (grey elements) and nonmetal elements (green elements) are metalloid in character (pink elements).
  • Within the p-block at the boundary between the metallic elements (grey elements) and nonmetal elements (green elements) there is positioned boron and silicon that are metalloid in character (pink elements), i.e., they have low electrical conductivity that increases with temperature.

• Soil Composition

  • Soil is a mix of varying amounts of inorganic matter, organic matter, water, and air.
  • inorganic mineral matter, about 40 to 45 percent of the soil volume
  • The four major components of soil are shown: inorganic minerals, organic matter, water, and air.

• Fungi as Plant, Animal, and Human Pathogens

  • Some fungal pathogens include (a) green mold on grapefruit, (b) powdery mildew on a zinnia, (c) stem rust on a sheaf of barley, and (d) grey rot on grapes.

• Basics of DNA Replication

  • Grey indicates the original parental DNA strands  or segments and blue indicates newly-synthesized daughter DNA strands or segments.

• Fungi Habitat, Decomposition, and Recycling

  • Fungi are the major decomposers of nature; they break down organic matter which would otherwise not be recycled.
  • The food web would be incomplete without organisms that decompose organic matter .
  • The action of fungi releases these elements from decaying matter, making them available to other living organisms.
  • Trace elements present in low amounts in many habitats are essential for growth, but would remain tied up in rotting organic matter if fungi and bacteria did not return them to the environment via their metabolic activity.

• Biogeochemical Cycles

  • The elemental components of organic matter are cycled through the biosphere in an interconnected process called the biogeochemical cycle.
  • However, the matter that makes up living organisms is conserved and recycled.
  • Because geology and chemistry have major roles in the study of this process, the recycling of inorganic matter between living organisms and their environment is called a biogeochemical cycle.
  • It is important for leaching certain components of organic matter into rivers, lakes, and oceans, and is a reservoir for carbon.

• The Protein Synthesis Machinery

  • The anticodon-containing loop is at one end of the molecule (in grey here) and the amino acid acceptor arm is at the other end of the molecule (in yellow here) past the bend of the "L".

• Nutrients from Other Sources

  • This may occur with plants that are parasitic or saprophytic: ingesting and utilizing dead matter as a food source.
  • A saprophyte is a plant that does not have chlorophyll, obtaining its food from dead matter, similar to bacteria and fungi.
  • Most saprophytes do not directly digest dead matter.
  • Instead, they parasitize mycorrhizae or other fungi that digest dead matter, ultimately obtaining photosynthate from a fungus that derived photosynthate from its host.
  • Saprophytes, like this Dutchmen's pipe (Monotropa hypopitys), obtain their food from dead matter and do not have chlorophyll.

• Physical Properties of Soil

  • The O horizon has freshly-decomposing organic matter, humus, at its surface, with decomposed vegetation at its base.
  • This horizon is typically darkly colored because of the presence of organic matter.