State the characteristic features of Kingdom Monera.

(N/A) $\rightarrow$ Bacteria are the sole members of the Kingdom Monera.
$\rightarrow$ Occurrence: Bacteria are the most abundant microorganisms which occur almost everywhere.
$\rightarrow$ Hundreds of bacteria are present in a handful of soil.
$\rightarrow$ They also live in extreme habitats such as hot springs, deserts, snow, and deep oceans where very few other life forms can survive.
$\rightarrow$ Many of them live in or on other organisms as parasites.
$\rightarrow$ Types based on shape: Bacteria are grouped under four categories based on their shape:
$1$. The spherical Coccus (Pl. Cocci)
$2$. The rod-shaped Bacillus (Pl. bacilli)
$3$. The comma-shaped Vibrium (Pl. Vibrio)
$4$. The spiral-shaped Spirillum (Pl. Spirilla)
$\rightarrow$ Mode of nutrition: Though the bacterial structure is very simple, they are very complex in behavior.
$\rightarrow$ Bacteria show the most extensive metabolic diversity.
$\rightarrow$ Some of the bacteria are autotrophic, i.e., they synthesize their own food from inorganic substrates.
$\rightarrow$ They may be photosynthetic autotrophic or chemosynthetic autotrophic.
$\rightarrow$ The vast majority of bacteria are heterotrophs, i.e., they do not synthesize their own food but depend on other organisms or on dead organic matter for food.