Kingdom Monera

• The kingdom Monera is a success story spanning 3.5 billion years
• contains all of the Prokaryotes commonly called bacteria (singular, bacterium)
• Prokaryotic cells are relatively small and lack membrane-enclosed organelles***
• most have a cell wall, but it differs in molecular structure of the cell walls of plants and fungi!
• compared to eukaryotic cells, bacteria have smaller genomes, differ in genetic replication, protein synthesis and recombination.
• Monerans outnumber all eukaryotes combined
• Bacteria are individually microscopic, usually invisible to the naked eye
• Many people associate bacteria with disease or infection, but only a small minority of prokaryotes actually cause disease in humans. (1-10%)
• Monerans live in close proximity to organisms of other kingdoms and to themselves in what are called symbiotic relationships. They must get along with others!

Form and Function of Prokaryotes

• the word Monera is derived from Greek, meaning single, referring to the single-celled nature of the great majority of the prokaryotes.
• other bacteria can exist in two or several celled groups.
• Other forms of bacteria form permanent groups called colonies, which are permanent groups of identical cells.
• some bacteria species even exhibit a simple multicellular organization in which there is a division of labor between two or more specialized types of cells.
• the three most common shapes of bacteria are:
• Spheres (cocci) - there are cocci, dicocci, streptococci and staphylococci
• Rods (bacilli) - can come in chains
• Spirals (spirilla) - singular
• many prokaryotes secrete sticky substances that form still another protective layer called a capsule outside the cell wall.

Time #

0 1

2 2

4 4

6 8

8 16

10 32

12 64

14 128

16 256

18 512

20 1,024

22 2,048

24 4,096

26 8,192

28 16,384

30 32,768

32 65,536

34 131,072

36 262,144

38 524,288

40 1,048,576

42 2,097,152

44 4,194,304

46 8,388,608

48 16,777,216

50 33,554,432

52 67,108,864

54 134,217,728

56 268,435,456

58 536,870,912

60 1,073,741,824

Growth Reproduction and Gene Exchange

• neither mitosis or meiosis occurs in the kingdom Monera; this is another fundamental difference between prokaryotes and eukaryotes. ***
• Bacteria reproduce only asexually by mode of cell division called binary fission where the bacterium is continuously synthesizing DNA
• some bacteria form resistant cells called endospores where the DNA is encapsulated by a durable wall.
• these endospores can survive many different kinds of harsh climates, in- fact, recently, scientists have discovered 11 000 year-old bacteria in the intestinal contents of the partially preserved remains of a mastodon.
• in natural environments, bacteria must compete for space and nutrients. A general feature of all microorganisms is the release of antibiotics, a chemical that inhibits the growth of other microorganisms.
• there are three mechanisms of genetic recombination in bacteria:
• Transformation - genes are taken up from the surrounding environment, allowing for genetic transfer in bacteria
• Conjugation - genes are transferred directly from one bacterium to another.
• Transduction - genes are transferred between bacterium by means of viruses.
• Mutation is the major source of genetic variation in prokaryotes. Mutations are amplified in bacteria because a generation can last only minutes or hours and a good mutation would quickly reproduce into large quantities.