Small Cell Types: An Overview

Cell types explore learning gizmo How do you know if something is alive? Describe some of the characteristics of living things. you can know by the order, sensitivity or response to the environment, reproduction, adaptation, growth and development, homeostasis, energy processing, and evolution. Humans, plants and mushrooms are all alive. What do these organisms have in common? They all grow, they're all living. Drag the Coarse focus slider until the sample is focused as well as possible. Then, improve the focus with the Fine focus slider. What do you see? I see hexagonal cells with a green cellular wall Select the 400x magnification. If necessary, adjust the fine focus. I see that the cell wall is made up by small green spheres called Now, what do you see? chloroplasts Match: Read about each microscope part. Match the description to the part on the diagram. B,A,C,D,E,F Which focus knob is easier to use at 40x? 400x? coarse focus and fine focus Turn on Show labels. What structures can you see in human skin cells? Nucleus, cell membrane, and cytoplasm Turn off Show labels and turn on Show scale bars. The scale bar has a width of 20 micrometers, or 20 ¼ m. (There are 1,000 micrometers in a millimeter.) Using the scale bar, about how wide is a human skin cell? 30 micrometers Sample Organelles Estimated size (¼ m) Mouse skin Nucleus, Cell membrane, Cytoplasm 20pm Fly muscle Nucleus, Striation, Cell membrane, Cytoplasm An organelle is a cell structure that performs a specific function. Observe the samples below under the highest magnification. Click the Show labels checkbox to label the organelles. List the organelles and approximate size of the cells in each sample. 20pm Maple leaf Nucleus, Cell membrane, Cytoplasm, Cell wall, Chloroplast, Vacuole 10pm Elodea Nucleus, Cell membrane, Cytoplasm, Cell wall, 40pm Fungus Nucleus, Cell membrane, Cytoplasm, Cell wall, Vacuole, Septu 8pm What do all of these samples have in common? The nucleus and the cell membrane, as well as cytoplasm What is the approximate size of E. coli? 10pm What organelles are present in E. coli? Cell wall, cell membrane, cytoplasm, Flagellum, Pilus and Nucleoid. What organelle is missing from E. coli? Nucleus Turn on Show labels. Does sand/silt have any internal structures? Yes sand/silt have internal structures. Do you think sand or silt is alive? Explain. No sand is not alive because it can't die 1/4 Collect data: Use the microscope to observe the samples listed in the table below. For each sample, estimate the cell size and check off the organelles that are present. If there is no column for an organelle, list it in the Special structure(s) column. Sample Estimated size (¼ m) Nucleus Cell membrane Cytoplasm Special structure(s) Human neuron 15pm Yes Yes Yes Yes Human skin 10pm Yes Yes Yes No Human muscle 20pm Yes Yes Yes Yes Human blood 5pm Yes Yes Yes No What is the function of the nucleus? The nucleus contains the cell`s DNA. The nucleus controls the cell by regulating when genes are turned on and off What is the function of the cytoplasm? gel-like substance that is composed mostly of water and contains all of the cell's organelles What is the function of the cell membrane? A lipid bilayer that surrounds and protects the cell, regulating what goes in and out. Neurons transmit messages in the form of electrical and chemical Click on the axon label to read the description. What is its function? signals, through axons and dendrites, from one part of the body to another. What is the function of a dendrite? Dendrites convert these signals into small electric impulses and transmit them inward, in the direction of the cell body. What do muscle cells have that other cell types do not? They have multiple nuclei within each cell What is a striation and how does it help muscle cells function? The primary function of striated muscles is to generate force and contract in order to support respiration, locomotion, and posture and to pump blood throughout the body What is the function of red blood cells? It Carries oxygen from the lungs to different parts of the body. What is the function of white blood cells? They protect you against illness and disease. What organelle is missing from the red blood cells? Nucleus In general, are there any major differences that you can see? Explain. The blood is different in humans and frog as humans red blood cells don't have a nucleus while that of frogs have a nucleus in the red blood cells What organelle do frog RBCs have that human RBCs do not? Main difference in human and frog RBC is human RBC are non-nucleated. Extend your thinking: Many types of cells, such as the ones in this Multicellular organisms, like people, are made up of many cells. activity, live together in groups, called tissues. A tissue is a group Cells are considered the fundamental units of life. The cells in of similar cells that together carry out a specific function. Describe 2/4 how the skin cells, neurons, muscle cells, and blood cells you have complex multicellular organisms like people are organized into observed relate to the functions of skin, nerve, muscle, and blood tissues, groups of similar cells that work together on a specific tissue. task. Observe: Compare the microalgae, the Elodea leaf cells, the maple leaf cells, and the root hair cells at 400x. Hand draw in the circles below or click on the circles and select EDIT to use the drawing tool. M What structures do all of these cells have in common? Nucleus, Cell membrane, Cytoplasm, Cell wall, Vacuole What structures are missing from the root hair cells? Chloroplast What is the purpose of this structure, and why do you think it is missing from the root hair cell? Doing the Photosynthesis and this structure is missing from the root hair cells because the sunlight doesn't reach them. How are the algae cells different from the other cells? They are isolated Explore: Which other samples in the Gizmo do you think represent unicellular organisms? Bacteria, fungi, algae, protists, Watch the motion of the protists at 100X and 400X. What structures allow each protist to move? Amoeba: Pseudopodium Euglena: Flagellum Paramecium: cilium Amoeba it looks like a small octopus with only two legs that move towards the body and away from it as well. They are also a triangular shape. Euglena it looks like it has a tail on the end of the body, which is away from the point. Paramecium In the table below, draw the structures that allow the protists to move on their images on the left and describe the structures in the spaces on the right: It looks like little hairs that move back and fourth around the whole body. Which protist is photosynthetic? How do you know? Euglena because it is the only one with a chloroplast. Find two structures that help E. coli move and describe them below: Name: Pilus Description: it has small hairs surrounding it helping it attach to other cells Name: Flaggulem Description: It has a tail that allows the cell to swim/move around Do protists (amoeba, Euglena, Paramecium) use similar structures to move? Explain. Yes, They all use either the pilus or flagellum to move around and attach to other cells. Click Play (). What happens? The ATP positive control and sample started glowing green and the Phenol red positive control and sample turned orange Does the worm neuron sample produce ATP? It does How do you know? because the positive control for ATP started to glow which means it has ATP. What happens to the phenol red? it turned orange When CO2 combines with water it forms carbonic acid. How does this explain the phenol red result? There is CO2 in the neutrons Based on the test results, are the worm neurons alive? Yes What happens to the phenol red? only the positive control turns orange 3/4 Click Reset (), then click on the light switch to turn off the lights. Click Play to run the experiment in the dark. What happens? The ATP positive control and sample started glowing green and the Phenol red positive control and sample turned orange Based on the test results, are maple leaves alive? Yes Collect data: Using the table below, select the sample on the LANDSCAPE tab. Perform the experiment in the light on the TEST FOR LIFE tab. Turn off the light by clicking on the light switch and perform the experiment again in the dark. Record the results below. Sample Light - ATP Light Respiration Dark - ATP Dark - Respiration E. coli Yes Yes Yes Yes Fungus Yes Yes Yes Yes Human skin Yes Yes Yes Yes Maple leaf Yes no Yes Yes Root hair Yes Yes Yes Yes Protists Yes no Yes Yes Sand/silt No no no no Analyze: Which of the samples in the above table are alive? All excluding sand and silt How do you know? they respire and produce ATP Discuss: Based on the results of the experiment, which samples from the table above are likely to undergo photosynthesis? Maple leaf and protists How do you know? they do not respire in the presence of light Analyze: Small particles of silt are about the same size and shape as a cell. No Is silt alive? How do you know? Does not respire or produce ATP 4/4