Living Or Non-Living That Is the Question

Teacher Answer Key Living or Nonliving…That is the Question!

Starter ?’s What makes something living or alive? Do all living things have to have similar qualities? If so, what traits do they share? What makes them different than nonliving? Can nonliving things appear to be alive? How can this be? Objectives In this activity you will: Observe and compare living and nonliving things in order to compile a list of the characteristics of life Materials Unlabeled specimens Light microscopes Stereomicroscopes Methods Read the entire lab and follow all prelab instructions before coming to class.

1. Prelab : Brainstorm ideas on what traits you believe living things have in common and list at least five (5) in the data table. You will be adding more as you observe the specimens during the lab. 2. When you get to class, observe each of the numbered specimens and observe them closely. Be sure to follow any special directions for viewing the specimens at each lab station. 3. For each of the specimens you observe, place an “X” in the data table for each trait you observe in the specimen. Feel free to add new traits as they become apparent to you during your observations. 4. Repeat steps 2-3 for each of the specimens. 5. After you have made all your observations, review the data you collected, and in the last column of the data table, indicate whether you believe the specimen to be Living (L), Nonliving (NL), or Dead (D). Postlab Questions- To be completed individually after the lab.

1. How did you determine the difference between a living specimen and a nonliving one?

Answers will vary. Most will look for movement, cells, or evidence that it “eats” and releases wastes.

2. What is the difference between a nonliving specimen and a dead one? Non-living specimens were never alive, never had all the characteristics of life. However dead

Specimens at one point did have all the characteristics of life, but no longer do.

3. According to your data table, what traits do most living things have in common?

Answers will vary. Probably growth, movement, and cells.

Lab 4. What traits do nonliving things have in common?

Answers will vary. The important ones are: They don’t have cells and they don’t have DNA.

5. Why can it be difficult to observe all the traits common to living things?

Traits are not always easily observable. For example, need microscope to see if there are cells.

Some traits require time to determine whether or not the specimen exhibits that trait.

6. Pick a specimen from the lab that you categorized as nonliving and (for fun) argue that it is living. You must be sure to use what you have learned about the traits that make things living in your argument. Therefore, be sure to include characteristics that this nonliving specimen shares with other living things. This answer must be at least four (4) sentences long.

Answers will vary. However, student must have chosen a nonliving entity to argue, and their statements must be reasonably true. For example: Candle flame appears to reproduce, die, and respond to environment like living things.

Lab Living or Nonliving….That is the question! Specimen # and Descriptions

1 2 3 4 5 6 7 8 9 10 1. has cells

2. reproduces

3. moves

4. responds to environment 5. eats/poops

6. breathes

7. grows

8. has DNA

9. maintains homeostasis 10. has order

Living (L), NonLiving (NL), or Dead (D)? Sample items to put at the stations; yogurt; germinating seeds, flame, cheese/mold, yeast, hair, oil & water, cork, sea sponge, copper sulphate, cut flower, potted plant Lab 7. For the following items label them as Living (L), Nonliving (NL), or Dead (D) and then give a short one- sentence explanation for why you put it in that category. Be ready to defend your answer! Purpose here is not that students get the answer “right” but that they are thinking about the characteristics of life and can discuss them intelligently. a) HIV Virus Scientists still argue this one. It has DNA, but no cells. It can reproduce, but only using a cell’s

Organelles. It is made up of chemicals. Just because it can kill doesn’t make it alive. b) brown grass Tricky one…hibernating? May not show characteristics of life from above the soil, however when spring comes the grass continues to grow. c) fertilized chicken egg Living. Egg is a single cell.

d) egg bought in a grocery store Living/dead. Egg is a single cell. Eggs bought in the store were never fertilized, which means they don’t have a full set of DNA. e) your skin on the back of your hand Dead. Skin levels of the skin are alive, but on the surface the cells are dead and slough off.

f) hair on a fruit fly’s back Non-living. Hair is just protein, and although it is made by cells, it itself is non-living.

g) boiling water Non-living. H20 is just molecules, not cells. Although it can provide life, water itself is not alive.

Although it can kill, water itself can not die because it is not alive. h) whale sperm Living. Has DNA (albeit only half of the required # by the species). Sperm is a single cell that contains organelles that perform life functions.

Lab Notes to Teachers: Set up stations for students to observe various living, non-living, and dead. Consider adding notecards with tips on how to observe the specimen. If you do this as the first lab of the semester, you might want to have specimens already on slides on microscopes for students to observe. However, if students already have these skills, allow them to make the slides.

Include hand magnifying glasses and/or dissection microscopes for many of the stations.

Be sure to allow classtime for students to “argue” the living/non-living debate. It is a good way to get them critically thinking about the definition of life. They should come to understand that it is not always easy to determine. Some overall conclusions students usually come to:

Non-living can’t become living 2 non-living things can’t make a living thing

Also be cautious, the traits students pick are not always the best to use, because ALL living things must share all the qualities of living things. For example: Movement is one students usually pick, and while many living things do move, many do not (on their own volition) and many non-living things also move. Therefore, movement is not a good indicator of whether or not something is alive.