Single-cell Organisms

Life Science - Middle School

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Single-Cell Organisms © Copyright NewPath Learning. All Rights Reserved. 94-4731 Visit www.newpathlearning.com for Online Learning Resources. DNA ribosomes cell membrane cell wall flagellum cytoplasm pilli Single-cell (unicellular) organisms are the most abundant creatures on Earth. They live in ponds, in our food, and even in our bodies. Bacteria is a large part of this category of organisms. Bacteria Bacteria are simple unicellular organisms that can be found in nearly every environment on Earth. All bacteria are prokaryotic—they do not have a true nucleus or organelles with membranes. Bacteria are divided into two kingdoms— archaebacteria and eubacteria. Archaebacteria can make their own food and live in harsh conditions such as in very salty water or in very hot, acid springs. Protists Protists are eukaryotic organisms that have a true nucleus and membrane-bound organelles. Most protists are unicellular and live in water. Plant-like protists, called algae, contain chloroplasts and make their own food by the process of photosynthesis. Euglena is a unicellular algae. Animal-like protists are known as protozoa. They are single-celled organisms that move to find food. Amoeba and paramecium are classified as protozoa. deep ocean vent Eubacteria - rods & spheres Eubacteria have various shapes which range from spheres to rods and spirals. They are more common than archaebacteria and are found in soil, water and our bodies. While some eubacteria cause disease, there are many types that are beneficial to humans. Healthy bacteria live in our digestive system and help us with digestion and the production of certain vitamins. nucleus flagellum chloroplasts nucleus Amoeba Euglena Paramecium nucleus oral groove pseudopod (for movement) cilia (for movement) food vacuole food food vacuole
Pause and Review Label the bacteria with the following structures: pilli, cytoplasm, ribosomes, DNA, flagellum, cell membrane and cell wall Single-Cell Organisms © Copyright NewPath Learning. All Rights Reserved. 94-4731 Visit www.newpathlearning.com for Online Learning Resources. Label the paramecium with the following structures: cilia, cytoplasm, nucleus, food vacuole, cell membrane and oral groove