Behavior of Microorganisms

1. Behavior of Microorganisms Hydra, Planaria, Paramecium

2. Dissecting Scope Usually 10X eyepiece Usually 2X to 4x objective

3. Illumination System: • Usually lights switches can turn lights to shine above or below the specimen

4. Illumination • Transmitted light from below through thin specimen (like a fly wing) • Reflected light from above for opaque objects (like a penny)

5. Dissecting scope • Does not invert the object • Does not have to be transparent or translucent Letter “e” appears the same as how you put it under the lens e

6. 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

7. Look at colored print • What did you see when you put colored newspaper print under the lens? • ANSWER: A lot of colored dots

8. 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.

9. Contracted, the hydra looks like a tiny cactus. Its colorcomes from symbiotic algae living in the hydra's tissues.

10. Hydra Stretched Fully extended, its tentacles sweeping the water for its prey, the hydra reaches a height up to two inches.

11. 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.

12. Tentacles curled, a hydra is ingesting its prey. Its mouth is at right.

13. The hydra is at rest, digesting its meal.

14. A mature bud has extended itself into a long stalk and is about to pinch itself off and depart.

15. Good Luck, Little Buddy! • One hydra bud somersaults away from its parent as another grows. Hydras often have four buds at a time.

16. Is it worth it? • When autumn arrives, bringing conditions that threaten the survival of the hydra, it ceases to replace itself and goes sexual. For the hydra, the price of sex is usually death!

17. In the image shown right you will see the male organs just behind the arms; the female organ, much larger, is situated a bit lower on the animal.

18. In the image shown right the sperm is oozing out of the male organ, in the image shown below a ripe egg is visible.

19. The egg is coming from the parent.

20. Nerve Net • Hydra have a simple nerve-net which connects with the stinging cells in the tentacles.

21. 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.) • .

22. 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.

23. 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.

24. Planaria • Movement is accomplished by the use of cilia and also by muscular contractions. VIDEO - Planarian movment (Dugesia) (1.83 MB)

25. Drawing #4 - Whole mount of discharged nematocysts (stinging structure found within cnidocytes).  You must use high power (450X) to see these.