* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Cell Types
Survey
Document related concepts
Signal transduction wikipedia , lookup
Cell nucleus wikipedia , lookup
Cytoplasmic streaming wikipedia , lookup
Cell membrane wikipedia , lookup
Tissue engineering wikipedia , lookup
Extracellular matrix wikipedia , lookup
Programmed cell death wikipedia , lookup
Cell encapsulation wikipedia , lookup
Endomembrane system wikipedia , lookup
Cell growth wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cell culture wikipedia , lookup
Cytokinesis wikipedia , lookup
Transcript
BIOLOGY – Activity Cell types Period 1 2 3 4 5 6 7 8 Date: _____________ Station # _____ Names _____________________ _____________________ _____________________ _____________________ _____________________ Introduction There are many types and categories of cells. One of the major divisions of cell types is between plant and animal. While these cells have many things in common, there are certain specific structures that can easily distinguish them from each other. With the aid of a microscope, it is possible to see these differences quite easily. The most easily obtained animal cell is the human cheek cell. These cells are known as epithelial cells and line the inside of the cheek where they can be scraped off with little effort since they fall off continuously anyway and are replaced on a daily basis. Plant cells are also easily obtained but may or may not contain chloroplasts depending on the part of the plant they come from. The leaves of the water plant known as Elodea are ideal for seeing chloroplasts and do not have to be stained to see cell parts since the chloroplasts are very green due to all the chlorophyll they contain. Objective To observe and identify some of the basic differences between plant and animal cells and to gain practice in the art of staining temporary wet mounts Materials microscope slides cover slips flat toothpicks onion Elodea forceps Lugol’s iodine Methylene blue pipette Procedure ( part 1 ) 1. Place a couple of drops of water in the center of a clean glass slide. 2. Gently rub the inside of one of your cheeks with the blunt end of a flat toothpick using a gentle up and down motion. Do not use force since you are looking for cheek cells and not red blood cells! 3. Remove the epithelial cells from the toothpick by swirling the end of the toothpick gently in the drop of water on the slide. Dispose of the toothpick in the waste basket. Lower a cover slip at an angle over the drop of water that should now contain cells so that no water bubbles are present. 4. Place a single small drop of Methylene blue stain on the slide at the edge of the cover slip. Tear off a small piece of paper towel and hold it at the edge of the cover slip opposite the drop of stain. The paper towel should draw water from under the cover slip and pull the stain from the opposite side of the cover slip under the cover slip , thus staining the cells. 5. Examine the stained cheek cells with the microscope using the proper technique to focus them on high power. 6. Draw a diagram of a single stained cheek cell as seen under high power. Label the following parts: cell membrane, cytoplasm, nucleus. Draw your picture in the circle provided and on the blanks to the right specify the type of cell and the power of magnification at which it was viewed. When labeling parts, use straight, horizontal lines to point to the part and print the name of the part at the end of the line. Color your drawing to match the stain used. Procedure ( part 2 ) 1. Place a couple drops of water in the center of a clean glass slide. 2. Use the forceps to carefully remove the epidermal layer from the inside curved surface of a piece of onion and spread the piece out flat in the water on the slide. 3. Place a drop of Lugol’s iodine solution directly in the onion tissue and add a cover slip, trying to avoid any air bubbles. 4. Use proper technique to focus on a few cells on medium power. 5. In the circle provided, draw all that you see in the field of view and label the following parts: cell wall, cell membrane, cytoplasm, nucleus. As before, indicate the name of the specimen and the magnification. Use the proper color for contrast. Procedure ( part 3 ) 1. Obtain a small leaf from the tip of a sprig of the water plant Elodea. 2. Place the leaflet with its upper surface facing down on a clean glass slide and add a drop of water and a cover slip. 3. Use the proper technique to focus on high power and draw all that you see in the field of view. Label the cell wall, cell membrane, cytoplasm, and chloroplast and indicate the specimen name and magnification. Analysis 1. What are the functions of the following cell parts? a. cell membrane ________________________________________________ b. cell wall _____________________________________________________ c. cytoplasm ____________________________________________________ d. nucleus ______________________________________________________ e. chloroplast ___________________________________________________ 2. Describe the shape and appearance of a cheek cell __________________________ ___________________________________________________________________ ___________________________________________________________________ 3. Describe the shape and appearance of an Elodea cell. ________________________ ___________________________________________________________________ ___________________________________________________________________ 4. Which part of a plant cell gives it shape? _________________________________ 5. Which part of an animal cell gives it shape? _______________________________ 6. What cell structure did the Elodea have that the onion did not? ________________ 7. Do all plant cells contain chloroplasts? Why or why not? _____________________ ___________________________________________________________________ ___________________________________________________________________ 8. What is the purpose of staining? _________________________________________ 9. What cell structures(s) did you observe in the onion that provides evidence that onions are plants? __________________________________________________ 10. What cell structure(s) did you observe in Elodea that were not in the cheek cell? ________________________________________________________________ ______________________ ______________________ ______________________ ______________________ ______________________ ______________________ ______________________ ______________________