Value Paradox

There appears to be a great deal more DNA in eukaryotic organisms than is actually needed to code for the number of genes estimated for a specific species. This discrepancy is known as the C value paradox. Genome size seems to bear little relationship to organismal complexity or the number of genes encoded. For example, genome size varies widely among insect species, with up to 250-fold differences in C values known Petrov et al. 2000 . The locust Schistocerca gregaria has a C value of...

Mitosis

Cell Interphase

Somatic cells divide by mitosis, which produces two nearly identical daughter cells, each containing the same number of chromosomes as the original cell Figure 3.3 . Prior to the onset of mitosis, the chromosomes within the nuclear membrane are not visible by light microscopy, because they are not condensed. Cells not actively undergoing mitosis are in the interphase state. The cell cycle consists of a coordinated set of processes by which a cell replicates all its components and is divided...

Gut Symbionts in Arthropods

Habitant Enterobacteriaceae

Insects may contain complex and diverse societies of microbes in their guts, yet relatively little is known about how these resident microbes shape the physiology of their hosts Cazemier et al. 1997, Kaufman et al. 2000 . The primary habitat for microorganisms associated with insects is the hindgut. The termite gut is one of the better studied examples, and molecular tools are improving our ability to resolve the taxonomy of the complex relationships among termite gut symbionts. The hindguts of...