Presentation on theme: "Behavior of Microorganisms Hydra, Planaria, Paramecium."— Presentation transcript:
Behavior of Microorganisms Hydra, Planaria, Paramecium
Dissecting Scope Usually 10X eyepiece Usually 2X to 4x objective
Illumination System: Usually lights switches can turn lights to shine above or below the specimen
Illumination Transmitted light from below through thin specimen (like a fly wing) Reflected light from above for opaque objects (like a penny)
Dissecting scope Does not invert the object Does not have to be transparent or translucent e Letter “e” appears the same as how you put it under the lens
What happens? Move the ‘e’ to the right…it looks like it is going to the right as you look through the lens… There is no inversion. e
Look at colored print What did you see when you put colored newspaper print under the lens? ANSWER: A lot of colored dots
Hydra viridis Two layers of cells which make up the body of a Hydra polyp The outer clear layer (the ectoderm) is the one which contains the nematocysts, or stinging cells.
Contracted, the hydra looks like a tiny cactus. Its color comes from symbiotic algae living in the hydra's tissues.
Hydra Stretched Fully extended, its tentacles sweeping the water for its prey, the hydra reaches a height up to two inches.
Hydra Bud Snares a Cyclops with its tentacles, a hydra bud snares a Cyclops, a tiny, one-eyed crustacean, also named after an ancient Greek monster. The bell-shaped protrusion on the hydra's body (upper left) is a second hydra bud.
Tentacles curled, a hydra is ingesting its prey. Its mouth is at right.
Nerve Net Hydra have a simple nerve-net which connects with the stinging cells in the tentacles.
Earthworm. Cephalization – has a brain (that co-ordinates the information coming into it from the sensory cells. It then sends information to the muscle cells and other tissues through a network of nerve cells.)
Hydra Drawing #3 - Put a living Hydra in a drop of water on a depression slide. If there are no living Hydra available use a longitudinal section ( l.s.) slide. Hydra only display the polyp body form.
Planarians are hermaphroditic, that is, they contain both male and female sex organs. They can reproduce asexually simply by pinching in half; each half grows a new half.asexually
Planaria Movement is accomplished by the use of cilia and also by muscular contractions. cilia VIDEO - Planarian movment (Dugesia) (1.83 MB)
Drawing #4 - Whole mount of discharged nematocysts (stinging structure found within cnidocytes). You must use high power (450X) to see these.