Structure and Function of Single Celled Organisms . By: Melissa st . louis , anam subzwari & shannon neary. A Few Specifics! . Grade 8 Expectation: 3.5 Identify unicellular organisms and multicellular organisms and compare ways in which they meet their basic needs.
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Structure and Function of Single Celled Organisms By: Melissa st. louis, anamsubzwari & shannonneary
A Few Specifics! Grade 8 Expectation: 3.5 Identify unicellular organisms and multicellular organisms and compare ways in which they meet their basic needs. Skills: creative thinking skills, investigation, exploration, experimentation
Introduction In groups…. Compare the advantages and disadvantages of a “smart” phone and a home phone
Basic Information! Unicellular Organisms – is an organism that consists of one cell Multicellular Organisms- is an organism that consists of many/multiple cells
Basic Information Examples: Unicellular Organisms Bacteria Amoeba Examples: Multicellular Organisms Worms Frogs
Amoeba Some basic information… One celled organism Classification - EukaryotaProtista Protozoa Sarcodina Microscopic Live in fresh water, salt water, wet soil, & animalsasexual reproduction Moves by pseudopods (changes its shape) Eats algae, bacteria, plant cells, protozoa, metazoa by surrounding it (as seen in our activity), forming a vacuole which digests it and removes remains from the amoeba
Amoeba Activity In groups of 2-4 the following materials will be provided: Sticky Tack Plates (paper or plastic) Corn Syrup Beakers
Amoeba Activity Using the sticky tack, place it in the centre of the plate and press it down Using the beaker of corn syrup, place a toonie size amount to the side of the paper plate One group member, will take the plate and both hands and gently tip it in different directions, making the corn syrup move around the plate Another group member, try to surround the sticky tack
Amoeba What do you think it represents? What parts of the amoeba can you recognize? What is another essential component that would be present in the amoeba? Discuss among your groups, how you can demonstrate it in another way?
Paramecium Structure/Functions of a Paramecium Body • Unlike the amoeba, paramecium have a permanent shape.
Paramecium Cilia • All forms of life need to take in nutrition to survive, even single-celled organisms like the paramecium. • Paramecium live in fresh water pools or ponds and feed on microscopic organisms such as bacteria and single-celled algae. • The paramecium relies on hair like structures that surround them in order to move through their environment towards food. • Flickering movements of the cilia also create feeding currents.
Paramecium Paramecium and the Environment • If a paramecium comes into contact with an object, it can reverse the beating of the cilia to move back. • This allows the paramecium to change its direction slightly and then move forward. • It will continue to do this until it passes the object in the way. • This reaction tells us that paramecium are sensitive to the stimulus of touch.
Paramecium Oral Groove • Cilia are not only used to move paramecium through their environment, but are also used to sweep food particles through their oral groove. • The oral groove is a canal or passageway of the paramecium and it is used to ingest nutrients (like a mouth). • The cilia around the oral groove create a current of water; which moves the food organisms through the passageway.
Paramecium Food Vacuole • When enough food particles form at the base of the oral groove, they form a food vacuole. • This food vacuole then follows a specific route through the cytoplasm. • During this time, enzymes are secreted into the vacuole and the food is digested. • The digested nutrients are absorbed into the cytoplasm. • So a food vacuole is responsible for digestion
Paramecium Anal Pore • Once all the nutrients from the food vacuole have been extracted, the undigested matter is expelled through the anal pore.
Paramecium Contractile Vacuole • The contractile vacuole is responsible for osmoregulation. • Canals surround the vacuole and these canals absorb water through the process of osmosis. • Once the canals are filled with water, they pump the water into the vacuole. • Once the vacuole is full of water, the water is removed from the cell through a small pore.
Paramecium Macronucleus • The macrocucleus is larger than the micronucleus and controls all the functions of the cell except for reproduction. • The paramecium cannot survive without the macronucleus.
Paramecium Micronucleus • The microcucleus is smaller than the macronucleus and controls reproduction. • Under ideal conditions, paramecium can reproduce two or three times a day.
Paramecium Cheerios Plasticine Pipe Cleaners Stars Googly eyes
Suggestions/Modifications Using a wide variety of materials Having students get into groups and brainstorm an array of ideas when constructing paramecium Allowing students to have full creativity Next lesson: Bring in samples of pond water, river water and have the students look under a microscope!
References Biology Teaching and Learning Resourceshttp://www.biology-resources.com/ Serving Science and Technologyhttp://101science.com/paramecium.htm Microscopy-UK Microscopy and Microscopes Magazine http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artsep01/amoeba.html
References Amoeba http://www.enchantedlearning.com/subjects/protists amoeba.shtml Unicellular Organisms http://en.wikipedia.org/wiki/Unicellular_organism Multicellular Organisms http://en.wikipedia.org/wiki/Multicellular_organism
References Advantages/Disadvantages http://wiki.answers.com/Q/What_advantages_do_multicellular_organisms_have_over_unicellular_organisms