Prokaryotes Lack a true nucleus Unit 14 Prokaryotes Lack a true nucleus

Three domains of Prokaryotes Bacteria Human or animal disease. Many species even play beneficial roles by producing antibiotics and food. The soil teems with free-living bacteria that perform many essential functions Our bodies are covered with bacteria

Three domains of Prokaryotes Archaea: Life's Extremists...! live in extreme habitats such as thermal vents or hypersaline water. They may be extremely abundant in environments that are hostile to all other life forms.

Three domains of Prokaryotes Eukaryota Single celled eukaryotes – Euglena, Amoeba, Paramecium Mushrooms, bread molds, water molds, yeasts Flowering plants, gymnosperms (conifers), ferns, mosses Animalia

Three basic shapes of bacteria Prokaryotes Three basic shapes of bacteria Bacilli (bacillus, singular) are rod-shaped Cocci (coccus, singular) are spherically-shaped Spirilla (spirillus, singular) are spiral-shaped

Arrangements of bacteria Prokaryotes Arrangements of bacteria Chains (prefix strepto-) Clusters (prefix staphylo-) Twos (prefix diplo-)

Prokaryotes In 1884 Hans Christian Gram developed a staining procedure, Gram Staining. The composition of the cell wall of bacteria vary among species. Due to this difference bacteria can be divided into two groups; Gram positive and Gram negative.

Prokaryotes Gram positive bacteria have thick peptidoglycan cell walls and retain a purple color when stained with crystal violet.

Prokaryotes Gram negative bacteria have double cell walls. These cells retain the red color when stained with safranin.