Eubacteria & Archarbacteria Prokaryotes Eubacteria & Archarbacteria
Prokaryotes Unicellular organisms that lack a nucleus Prokaryotes are identified by characteristics such as shape, the chemical nature of their cell walls, the way they move, and the way they obtain energy.
Types of Prokaryotes There are two domains/kingdoms that contain prokaryotes Domain Bacteria- Kingdom Eubacteria Domain Archaea-Kingdom Archaebacteria
Classification-Shape Shapes: Rod-shaped = bacilli Spherical = cocci Spiral/corkscrew = spirilla
Classification- Cell Walls Prokaryotes can be distinguished by the presence of absence of peptioglycan Violet and red dyes are applied; violet stains peptidoglycan. Alcohol is used to wash the sample, then the red dye is applied. Gram-positive have thick walls that retain the violet stain. Gram-negative lose the violet dye and appear reddish from the secondary stain. They have an extra lipid layer outside their thin cell wall.
Classification-Movement Some prokaryotes do not move; other move using flagella (whip-like tails), or cilia (tiny hairs). Some move in snake-like motions, or secrete a slime to help them glide along.
Classification-Obtaining Energy Heterotrophs vs. Autotrophs Heterotrophs: must consume organic molecules Autotrophs: use light energy or chemical energy to make their own food
Classification-Growth & Reproduction Binary Fission: DNA is copied, and the cell splits in half Conjugation: A hollow bridge is formed between two cells and genetic material is exchanged Spore Formation: If growth conditions are unfavorable, an endospore may form; a thick internal wall is made to enclose the DNA and some of the cytoplasm; may remain dormant for months or years; e.g. Anthrax
Crossword!
Review: Quiz #3
Grudge Ball
Question #1 What are the eight levels of Linnaeus’s Classification from least inclusive to most inclusive.
Question #2 A koala bear’s scientific name is Phascolarctos cinereus. What does the scientific name tell us about the classification of a Koala bear? (Levels)
Question #3 Animals that create their own food using photosynthesis or chemosynthesis are called____________?
Question #4 An organism that is a prokaryote could be a member of which kingdoms?
Question #5 Name the following prokaryotes based on their shape. 1 2 3
Question #6 What are the 3 methods of reproduction that prokaryotes can undergo?
Question #7 Make a dichotomous key for the following set of aliens. A B C D E F
Question #8 An organism has a true nucleus, is an autotroph and doesn’t have cellulose in their cell wall. What Domain and Kingdom would this organism belong to?