How many chloroplasts are in a plant cell? What is Cyclosis botany? In the fluid form it flows freely and can be observed carrying organelles and other inclusions in the cell. Cyclosis is very variable in plant cells. What causes cytoplasmic streaming? Cytoplasmic streaming occurs due to the motion of organelles attached to actin filaments via myosin motor proteins. Actin is a polar molecule, which means that myosin only moves in one direction along the actin filament.
What is vacuole cell? Vacuoles are storage bubbles found in cells. They are found in both animal and plant cells but are much larger in plant cells. Vacuoles might store food or any variety of nutrients a cell might need to survive. They can even store waste products so the rest of the cell is protected from contamination. Which plant is used for the study of mitosis in this exercise? What plant was used in your study of mitosis? You have questions-we have answers.
Get general information, care guides, and product information here. Brush up on the latest instructional strategies and pedagogy with information from our teaching partners, instructional designers, and academic consultants. Feeling the pinch from the current economy? Carolina understands. In this lab students observe Elodea leaves under magnification. They will see cell walls and chloroplasts.
From the movement of chloroplasts they will infer that cyclosis, or protoplasmic streaming, is occurring. They also will observe that most chloroplasts are pressed tightly against the cell wall and should infer from this that much of the cell is occupied by a vacuole.
Elodea , , or In Elodea , cyclosis is easy to observe because chloroplasts move with the cytoplasm as it flows. Light and heat stimulate cyclosis in Elodea. Tungsten or halogen substage microscope lamps produce both heat and light, so after 2—3 minutes, students should be able to observe the movement of chloroplasts. If your microscopes have fluorescent or LED lamps, these produce very little heat and often will not stimulate cyclosis. To provide the needed heat, use a desk lamp equipped with a halogen bulb.
Position the lamp so that it shines down on the lab bench. After a few minutes, the surface of the lab bench should become noticeably warm to the touch. Students can place their slides on this warm surface for 3 minutes and then look for signs of cyclosis. A somewhat better arrangement is to position the lamp so that it shines directly onto the stage of a microscope, thereby heating the slide while students view it. Not all slides will show cyclosis, so have students share those that do, so that everyone has the opportunity see the movement.
Ensure that students understand and adhere to safe laboratory practices when performing any activity in the classroom or lab.
Demonstrate the protocol for correctly using the instruments and materials necessary to complete the activities, and emphasize the importance of proper usage. Use personal protective equipment such as safety glasses or goggles , gloves , and aprons when appropriate.
Model proper laboratory safety practices for your students and require them to adhere to all laboratory safety rules.
Although you can receive Elodea and use it the same day, it is much better to condition the plants under lights for 2 days. On the day of the lab set up 2 or more small tanks or large beakers, each containing water and Elodea.
Place forceps and droppers alongside each container. Also, set up stations for pickup of microscope slides, coverslips, and dissecting needles. Optional: If students have studied osmosis, they can observe plasmolysis. Students are unlikely to observe nuclei in Elodea cells. However, nuclei are easily observed in stained cells of onion skin. Quarter an onion and separate the layers. Use forceps to remove the skin from the inner concave surface of a layer.
Cut or tear the onion skin into small pieces that will fit under a coverslip. Place the onion skin on a microscope slide and smooth out as many wrinkles as possible. Add a drop of stain to cover the onion skin. A number of stains can be used, including iodine solutions iodine-potassium iodide , Lugol solution , Gram iodine , crystal violet , toluidine blue , and methylene blue.
After 1 minute, rinse away the stain with tap water, add a coverslip, and observe the cells. Nuclei will be evident. In addition to light and heat, pH also influences cyclosis. Have students conduct a study to determine at what pH cyclosis is most likely to occur. We use cookies to provide you with a great user experience. By using our site, you accept our use of cookies. You can review our cookie and privacy policy here.
To calculate the actual size of a cell using a highly magnified image and mathematical equations. Introduce students to the aquatic plant Elodea by showing them the image of Elodea in an aquarium.
Or, if you have acquired Elodea plants for the Going Further microscope activity, display the plants. Review with students the major differences between plant and animal cells.
Show students the video of Elodea leaf cells. Which cellular structures can they observe? In discussing the moving chloroplasts, ask students if there are areas that the chloroplasts seem to avoid and what might account for this. Replay the video if students would like to watch the chloroplasts more carefully. The Elodea leaf is composed of two layers of cells. Only one layer ofcells is in focus when using the high power 40x objective. Is a vacuole or a cell wall visible?
Why can't you see the nucleus in an elodea leaf? How big is an onion cell? How do you measure the size of a cell? What is the average size of a cheek cell?
Do cheek cells have a nucleus? Why are chloroplasts green? Why plastids are absent in cheek cells? Where should an adjustable condenser be set for maximum resolution?
Term Why should only lens paper be used to clean microscope lenses? What did you observe on the elodea leaves? Can you see the mitochondria in an elodea cell? Model Organisms. Do onions have chloroplasts? Are chloroplasts moving or stationary? What color were the elodea cells? What does elodea mean?
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