1. Kingdom Monera Bacteria Structure, Shape, Movement & Reproduction

2. Common Characteristics Bacteria are prokaryotic cells They are 1-10 um in length (much smaller than eukaryotic cells) Except for ribosomes, there are no cytoplasmic organelles Lack a defined nucleus Most have a cell wall, cell wall may be surrounded by a capsule May have a flagella for movement

3. Typical Prokaryotic Cell

4. Bacteria Shapes Bacteria are commonly in three basic shapes Coccus (sphere) Bacillus (rod) Spirillium (spiral)

5. Cell Wall Characteristics Different types of bacteria have different types of cell walls Differences in cell wall composition can be studied using gram staining Depending on their cell wall, bacteria can be classified as Gram-Positive or Gram Negative

6. Gram Positive Bacteria These bacteria have a thick layer of peptidoglycan in their cell walls These bacteria retain dye-iodine complex in their cell walls and appear purple under the microscope

7. Gram Negative Bacteria These bacteria have a thin layer of peptidoglycan in their cell walls These bacteria do NOT retain the dye These bacteria appear pink under the microscope

8. Bacterial Movement Flagella Long whip like structure that propels bacteria May have none, one or several

9. Bacterial Movement Pilli (cilia) Short hair like appendages that adhere bacteria to different surfaces

10. Bacterial Movement Slime Some bacteria secrete slime like material they glide along No Movement Some bacteria do not movement all

11. Bacterial Reproduction In favorable conditions, bacteria can grow and reproduce as often as every 20 minutes Methods of Bacterial Reproduction Binary Fission Conjugation Spore Formation

12. Binary Fission Asexual form of reproduction There is no exchange or recombination of genetic material How? When a bacterial cell has grown to double its original size, it replicates its DNA and divides in half to produce two identical daughter cells

13. Binary Fission

14. Conjugation A form of sexual reproduction An exchange of genetic material is involved When 2 cells conjugate, a long protein bridge is formed between them Genetic info is transferred from one cell to the other via this bridge The recipient now has new genetic material & the genetic diversity in the population has increased This helps the bacteria survive environmental changes

15. Conjugation

16. Spore Formation Not really a form of reproduction but enables the bacteria to survive In unfavorable conditions, bacteria can form endospores The endospores stay dormant until conditions are favorable again When conditions are favorable, the endospore will release the bacterial cell

17. Spore Formation