Download presentation
Presentation is loading. Please wait.
Published byHarry Miles Modified over 9 years ago
1
Prokaryote Microorganisms 11.0 Classify animals according to type of skeletal structure, method of fertilization and reproduction, body symmetry, body coverings, and locomotion. Examples: skeletal structure - vertebrates, invertebrates; fertilization- external, internal; reproduction -sexual, asexual; body symmetry- bilateral, radial, asymmetrical; body coverings- feathers, scales, fur; locomotion- cilia, flagella, pseudopodia
2
Prokaryotes: What is a prokaryote? Lack a nucleus Unicellular What 2 Kingdoms would include prokaryotes? What 2 Domains would include prokaryotes? Recall that under the 5 Kingdom Classification System, ALL prokaryotes were included in one kingdom – Monera.
3
Eubacteria (Domain Bacteria) Found almost everywhere Usually surrounded by a cell wall that protects it and determines its shape. Cell walls contain peptidoglycan _________________ surrounds the cytoplasm inside the cell wall. Source: http://danmarkltd.tripod.com/taxonomy/id6.html
4
Archaebacteria (Domain: ??) Lack peptidoglycan in the cell wall Have membrane lipids not found in other organisms Can be found in extreme environments DNA sequences of key genes are more like those of eukaryotes than eubacteria
5
Identification of Prokaryotes: 1. Shape: a. Bacilli – rod-shaped b. Cocci – spherical c. Spirilla - spiral and corkscrew-shaped 2. Cell walls – Gram staining a. Violet (primary) stain stains the peptidoglycan b. Alcohol wash will rinse the stain from thin- membraned organisms (Gram -), but not from thick-walled (Gram +). c. Red (counterstain) will make Gram - organisms look pink or light red. 3. Movement – no movement, flagella, snakelike movements, or gliding along secreted slime.
6
Source:http://mrwrightsclass.net/projects/period4/paige_maria_andr eas/EUBACTERIA/eubacteria.html
7
Metabolic Diversity Heterotrophs: Chemoheterotrophs – use organic (carbon-based) compounds for energy Photoheterotrophs – use light for energy, but also need organic compounds for carbon Autotrophs: Photoautotrophs – use _______ to convert ____ and _____ to ________ and ________. One type of photoautotroph is cyanobacteria, which contain a bluish pigment and chlorophyll . Chemoautotrophs: make organic molecules from CO 2, but without light Use energy from chemical reactions occurring around them
8
Growth & Reproduction 1. Binary fission – a bacterium doubles in size, duplicates its DNA, and divides in half. 2. Conjugation – the exchange of DNA across a hollow bridge formed by intertwined pili. 3. Spore formation – under adverse conditions, some organisms can form a thick internal wall around its DNA until conditions are more favorable. Summary: some sexual, some asexual methods
9
Why Are Bacteria Important? Decomposers Nitrogen fixers for plants Human uses: Foods and beverages Clean up oil spills Synthesize drugs and chemicals Help us digest foods
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.