1 Lab 7. Biodiversity YOUR NAME ______________________________ LAB PARTNERS NAMES: ______________________________ ______________________________ ______________________________ OBJECTIVES Ø Identify key structures found in all life forms. Ø Compare and contrast the domains Bacteria and Eukarya. Ø Compare and contrast the 5 kingdoms of life: Plantae, Animalia, Fungi, Protista, and Bacteria. PRELAB Ø Read Chapter 2.5 and Chapter 13 of your textbook. INTRODUCTION Life consists of three major groups that we call domains: Bacteria, Archaea, and Eukarya. Bacteria and Archaea are prokaryotic, while Eukarya are eukaryotic. The Archaea domain consists of organisms that we cannot explore in a typical lab environment. In this lab, we will explore the similarities and differences between Bacteria (prokaryotes) and Eukarya (eukaryotes). We will also start to explore the major kingdoms of life: Bacteria, Archaea, Protista, Fungi, Animalia, and Plantae. Systematists categorize organisms based on shared characteristics and evolutionary ancestry. One of the reasons for categorizing organisms in this manner is so that scientists can more easily talk about these organisms. For example, if you have 15 cousins and you are all going to the movies together, it is easier to say “My cousins and I are going to the movies.” than to list all your cousins by name. The meaning of the statement is more clearly understood by using the group term “cousins”. Notice that Bacteria and Archaea are both domain and kingdom names, however, the domain Eukarya is divided into four kingdom groups: Fungi, Protista, Plantae, and Animalia. MATERIALS NEEDED Ø Light microscope Ø Microscope slides and coverslips Ø Prepared slides of bacteria. Ø Euglena and Paramecium living specimens and prepared slides. Ø Elodea Ø Methylene Blue and toothpicks for cheek cell preparation. PROCEDURES Exercise A. Prokaryotes Bacteria are Prokaryotes. Two microscopes have been set up for you of two types of bacteria. Look through the microscope and draw BOTH specimens. Don’t forget to label! Use the posters provided in lab and your textbook to help you label important structures. How are these bacteria similar to each other? How are they different? 2 3 Exercise B. Eukaryotes-? Protista The Protista kingdom consists of a wide variety of organism, but it can be loosely divided into “fungal-?like”, “plant-?like”, and “animal-?like”. It takes a more expert eye to find fungal-?like protists, so we will focus on exploring “plant-?like” vs. “animal-?like” protists. You will prepare wet mount slides of an “animal-?like” protist (paramecium) and a “plant-?like” protist (euglena). Observe and draw these specimens. Label important structures. List magnification. Venn Diagram 1. Note Similarities and Differences between Euglena and Paramecium Euglena Paramecium 4 Exercise C. Eukaryotes-? Plantae Prepare a “wet mount” slide of an Elodea leaf. Draw what you see at 100X in the circle below. Label all of the structures you can clearly see. Exercise D. Eukaryotes-? Animalia Prepare a “wet mount” slide with of your cheek cells. 1. Obtain a clean glass slide (you may want to clean it again yourself with a Kimwipe). Be careful to hold the slide by the edges to avoid smudging it. 2. Place one (1) drop each of water & methylene blue in the center of the slide. 3. Gently rub the inside of your cheek with the blunt end of a toothpick. 4. Stir the cheek material (you may not be able to see any) into the methylene blue in the center of the slide. If the stain appears very dark, add a drop of water. 5. Apply a cover slip; touch one edge of the cover slip to the edge of the drop of liquid. Hold the coverslip while the liquid runs along the entire edge. Then gently lower the coverslip over the specimen. 6. Dispose of toothpick in the beaker of bleach provided. 5 Draw what you see at 400X in the circle below. Label all of the structures you can clearly see. Venn Diagram 2. Note Similarities and Differences between Animalia and Plantae. Animalia Plantae 6 Additional Questions Based on your observations of the specimens in today’s lab, what are some of the major differences between prokaryotes and eukaryotes? What organelle do you see in the Euglena and plant cells that you don’t see the Paramecium and animal cells? What does this suggest about how these organisms differ in how they obtain energy? Why do both plants and animal cells have mitochondria? Be prepared to discuss your Venn Diagrams and other observations with the class.