Studying Living ThingsWith the Scientific MethodThe Big Ideas
- All living things have certain characteristics in common.
- Scientists use experiments and careful observations to answer questions.
Characteristics of Living ThingsGOAL: Learn the characteristics that all livings share.You know that a cat is alive, but how do you know? Most students will say "because it moves!" But a rosebush is alive too, and when was the last time you saw a rosebush move? So what do a cat and a rosebush have in common? Follow the steps below to discover the characteristics of living things:
- How can you use the scientific method to determine if something is living or non-living?
The Nature of ScienceWhat are scientists like? How do they think? What do they do? (Pay attention to the process they use to answer questions.) Find out by reading the article "The Nature of Science." As you read, take Cornell notes in your notebook (right side and summary only; we'll do the rest later as reviews).What is the scientific method? How do we use it to answer questions about living things? Read about it and practice identifying the different elements of the scientific method by reading page 220 in your Holt Life Science textbook. On a copy of that page, underline the different elements of the scientific method in different colors:
- In your science notebook, brainstorm as many things as you can think of that are true about all living things. Organize your thoughts in an appropriate thinking map.
- Read Chapter 2 Section 1 in your Holt Life Science textbook. Get an overview first by reading just the headings and subheadings; then read the entire text. Don't forget to read the captions that go with the pictures. As you read, take Cornell Notes in your Life Science textbook (right side and summary only; we'll do the rest later as reviews).
- Pretend you are a scientist in the field. You have collected a specimen of a slimy goo you believe may be alive, but it's not obvious. Write a short story describing your discovery and explaining how you would figure out if the goo was actually microbial life.
Scientist IllustrationWhat characteristics does a scientist have? How do scientists think? Solve problems? You read about this in "The Nature of Science" handout you received, and you also read about the scientific method on page 220. Create a picture that shows the qualities of scientists and how they use the scientific method.
- Question - Red
- Hypothesis - Orange
- Procedure - Yellow
- Data - Green
- Conclusion - Blue
You may create any one of the following:
1. A single illustration of a scientist with details to show the characteristics and scientific method
2. A collage with several pictures illustrating the various characteristics and parts of the scientific method
3. A slide show with several pictures illustrating the various characteristics and parts of the scientific method
Whichever method you choose, you must also include an explanation of how your picture or pictures illustrate the information requested. This may be 2-3 paragraphs or you may write a good caption, using complete sentences, for each characteristic / method.
You may create your project by hand or on the computer.Learn to Use a Microscope
GOAL: After you complete the virtual lesson, take a prepared microscope slide to the microscopes and get the specimen into focus.(Note: As you work, take notes in your science notebook that will help you when you go use the actual microscope.)
Most cells are extremely small. How small? Check out the “Cell Size and Scale” interactive animation to compare the size of different cells and molecules to a coffee bean and even a single grain of salt!
So how do we see something so small? You can’t see it with just your eye. You need a microscope. To understand how to use it, start by learning the names of the parts. The Microscope Parts study set on Quizlet will help you a lot! Once you have a hang of the names, complete the tutorial (“Getting Started”) on the Virtual Microscope.Once you have placed a virtual specimen on the virtual microscope and gotten it into focus on the highest power lens, get a prepared slide from your teacher and take it into the real microscope. (Be ready to explain the basic procedure to your teacher.) Then, try to get the specimen into focus on the highest power. Use the same procedure you used on the virtual microscope.Is It Alive? (Cells)
GOAL: Prepare a wet-mount slide with our specimen on it. Observe it under the microscope to see if it is made of cells.(Note: In your notebook, begin your lab report by writing your question and hypothesis. As you watch the instructional video, add the materials and procedure to your report. Finally, when you make your slide, add the data section to your report where you will draw and describe what our specimen looks like under the microscope.)How will you know if our specimen looks like cells? Before examining your own slide, check out this slideshow of pictures of living and non-living things under a microscope. Make notes in your notebook comparing the what the two look like under the microscope. This section of your lab report is called "Background."Is our specimen made of cells? Let’s examine it under the microscope. To find out how, watch this short video on “Preparing a Microscope Slide.” This type of slide is called a wet-mount slide. (Note: You can use this same procedure to answer other questions like: Could there be bacteria or a paramecium in that pond water? Is there fungus in the soil?) Write your notes in the "Procedure" section of your lab report in your notebook.
Now, prepare your own slide and place it under the microscope. Do you see anything that looks like a cell? Draw and describe what you see. You do not need to draw the entire slide you see, just draw 3 or 4 bits of the specimen in detail (no general sketches). This goes in the "Data" section of your lab report.Now draw your conclusion. Is our specimen made of cells? Use the "How to Write a Lab Report" reference page to make sure you have written a complete conclusion.(If you were not able to make a slide, here are photos of our specimen under the microscope.)
Be sure to wipe up any spilt water or specimen. Throw away any tissues or other material you used to prepare the slide or clean up. Use a wet-erase marker to label the slide with your table and period number; then give it to your teacher.Is It Alive? Growth, Metabolism, and Respiration ExperimentGOAL: Conduct an experiment to see if our specimen uses energy. Compare what happens when you give it food to what happens when you don't.(Note: In your notebook, begin your lab report by writing your question and hypothesis. I will give you a copy of the materials and procedure to tape in. Don't spend time writing those by hand.)
All living things use energy; this is called metabolism. Living things get this energy from their food. The most basic food is the one produced by plants during photosynthesis. Do you know what that is? (Yup, sugar.) When organisms release energy from food, they produce carbon dioxide gas (CO2). Breaking down food to release energy is called cellular respiration.
Cellular respiration is related to your respiration (breathing). When your cells break down food molecules, they release carbon dioxide. This carbon dioxide is carried to your lungs where you breathe it out, and we call breathing respiration too! Not all living things breathe, but all living things respire and release CO2.
To find out if our specimen respires, let’s give it some food and water and see what happens! Since sugar is the most basic food, let’s give it sugar and see what happens.Before you begin your experiment, watch these videos to learn how to measure using a scale and a graduated cylinder. You also need to know how to measure the circumference of a balloon.The growth, metabolism, and respiration lab directions should be in your lab tray. Before you begin the experiment, write the lab title, question, and hypothesis into your notebook, and set up a data table to record your data. (You will receive a handout of the materials and procedure to tape into your notebook, so you do not need to write those by hand.)If you didn't get to finish the experiment and collect your own data, you may use mine.Is It Alive? DNA Extraction
GOAL: Attempt a DNA extraction to see if our specimen contains DNA.(Note: In your notebook, begin your lab report by writing your question and hypothesis. I will give you a copy of the materials and procedure to tape in. Don't spend time writing those by hand.)All living things have DNA. Does our specimen have DNA? Find out by trying to extract DNA. Do you remember what DNA looks like when you extract it? If not, take a minute to re-read “Michelles Ivestigation” on your science skills activity page.Before you begin your experiment, watch these videos to learn how to measure using a scale and a graduated cylinder. You will also need to know how to carefully pour a layer of liquid on top of another layer of liquid.The DNA extraction lab directions should be in your lab tray. Before you begin the experiment, write the lab title, question, and hypothesis into your notebook, and set up a data section to record your data. (You will receive a handout of the materials and procedure to tape into your notebook, so you do not need to write those by hand.)(If your group did not finish in time to draw and describe your data, use the photo on my welcome page to draw and describe the results of this experiment. That photo was from the same experiment in 2014.)