Single Celled Organisms Chapter 4 Single Celled Prokaryotes

Single Celled Organisms Chapter 4

Single Celled Prokaryotes � 2 Domains: Archae and Bacteria �Compose ½ of earth’s living mass �All Archae and Bacteria are unicellular

Single Celled Eukaryotes �The 3 rd Domain, Eukarya, contains some single celled organisms

Archae �Unicellular organisms �No nucleus �Have strong cell membranes that allow them to survive harsh climates: extremophile �Contain flagella- whip-like structures, tails, that allow the cells to move

Types of extremophiles � 1. thermophiles: organisms that prefer extreme heat, often above 100 degrees Celsius

� 2. Halophiles: organisms that live in extremely salty, or saline, environments, such as the Dead Sea or the Great Salt Lake

� 3. Acidophiles: organisms that live in very acidic environments

Extremophiles & Oxygen �Aerobic: organisms that require energy �Anerobic: organisms that do not require oxygen �Methanogens: anerobic extremophiles that live in intestinal tracts; produce methane

�Extremophiles & Mars

Bacteria �Unicellular prokaryotes �Normal cell membrane; not extremophiles �Colonies: bacteria live in large groups �Many have flagella to move �Plasmids: small sections of DNA in the cytoplasm of bacteria

Nitrogen Fixation �Process when some bacteria remove nitrogen gas from the air and convert it into ammonia for plants and animals to use �video

Coccus Bacteria �Spherical, circle shaped

Spirilla Bacteria �Spiral shaped

Bacillus Bacteria �Rod shaped

Roles of Archae & Bacteria in the Environment �Recyclers �Decomposers �Symbiotic Relationships �Mutualism �Commensalism �Parasitism

Recyclers �Prokaryotes that recycle carbon, nitrogen, phosphorus, iron, and other elements in the environment

Decomposers �Prokaryotes that break down dead organisms and organic matter into simpler compounds �carbon and minerals are released back into the environment

Symbiotic Relationships

Kingdom Protista �Eukaryotes �Many are unicellular, some are multicellular �Any eukaryotic organism that is not a fungus, plant, or animal, but is like a fungus, plant, or animal. �Most are in water, some on land or the human body

3 types of Protists �Plant-like �Fungus-like �Animal-like �Categorized by how they obtain their food

Plant-like Protists �Obtain food through photosynthesis �Do not have leaves or roots

Plant-like Protists: Examples � 1. Algae: lives in the water and contains chlorophyll

Plant-like Protists: Examples � 2. Diatoms: single-celled, type of algae �Found in fresh or salt water, and in moist soil or moist plant surfaces �A part of plankton

Plant-like Protists: Examples � 3. Euglena: unicellular protists; photosynthesis with light. �Red eye spot: a collection of pigment that detects light and moves toward light �When no light is present, it can engulf food

Fungus-like Protist �Fungus-like Protist’s cell wall is made of cellulose �A fungus’ cell wall is made of chitin 3 groups: �cellular slime molds �acellular slime molds � water molds- decomposers, Great Potato Famine

Animal-like Protists: Examples �Protists- unicellular, animals- multicellular 4 groups- based on how they move � 1. Zooflagellates- move by flagella

Animal-like Protists: Examples �Protists- unicellular, animals- multicellular 4 groups based on how they move � 1. Zooflagellates- move by flagella � 2. Sarcodines- unicellular move by pseudopod, false foot

Animal-like Protists: Examples �Protists- unicellular, animals- multicellular 4 groups based on how they move � 1. Zooflagellates- move by flagella � 2. Sarcodines- (amoeba) unicellular move by pseudopod, false foot � 3. Ciliates- unicellular, elastic membrane �Cilia- hairlike organelles for movement

Animal-like Protists: Examples �Protists- unicellular, animals- multicellular 4 groups based on how they move � 1. Zooflagellates- move by flagella � 2. Sarcodines- (amoeba) unicellular move by pseudopod, false foot � 3. Ciliates- unicellular, elastic membrane �Cilia- hairlike organelles for movement � 4. Sporozoans- produce spores

Yogurt �yogurt under microscope

Common Bacteria in Yogurt �lactobacillus bulgaricus streptococcus thermophilus