Reptiles

This lesson falls under our science homeschool curriculum on Biology. We recommend that this lesson be taught after the lesson on Amphibians.

1. Internet Access – Pull up the following:

1. Picture of Jacobson's organ

2. Picture of a yellow snake

3. Video of chameleon changing color

4. Video of snake shedding its skin

5. Video of Australian frilled lizard

6. Video of Hognose snake playing dead

7. Video of spitting cobra

1. Teacher: Ok - so last lesson we learned about fish. Today, we're going to learn about exciting animals called reptiles. Since you already know what reptiles look like, let's get started right away with this lesson. So, are you ready to learn all about reptiles? [Get positive response from Student and begin lesson]

1. Teacher: Great. Now, just like fish, reptiles are also vertebrates, which mean that all reptiles have backbones. Also, like fish, reptiles have scales, but they're thicker than fish scales. Another similarity of reptiles compared to both fish and amphibians is that reptiles are cold blooded, which means they need the warm their bodies by laying out in the sunlight and use the shade to cool off their bodies.

2. Teacher: So then, what makes a reptile a reptile? First of all, reptiles mostly belong to one of the following kinds of animals: turtles, lizards, snakes, crocodiles, and alligators. So, if you're not one of these animals, you're probably not a reptile. Now, based on what you already know about some of these animals, you can correctly guess that, reptiles can live for a long time far away from water. Here's something you may not know - reptiles must breathe air and so cannot breathe under water. Also, most reptiles are oviparous, that is, they lay eggs, and they do that on land. Finally, most reptiles, except turtles, have teeth.

3. Teacher: Now, just like us humans, reptiles have eyes, mouths, legs, you know the things that you would expect reptiles to have. But one thing that reptiles use to smell and taste that humans don't use is called the Jacobson's organ. Can you say "Jacobson's organ"? [Have the Student repeat this word]

4. Teacher: Just in case you're wondering, it's called the Jacobson's organ because a doctor by the name of Ludvig Jacobson found it long ago back in 1813. Anyway, this Jacobson's organ is a small hole on the roof of each reptile's mouth which helps the reptile find food, and find out information about its environment. Here's a picture of a snake that points out where the Jacobson's organ is. [Show the Student the picture of the Jacobson' organ]

5. Teacher: Now, do you notice how close the snake's tongue is to its Jacobson's organ? That's why you see snakes always flicking its tongue out; the tongue is used to pick up all the smells and tastes of the snake's surroundings, which then can be sensed by the snake's Jacobson's organ. This tells the snake exactly what is around the snake's environment. Can you tell me another reptile that flicks its tongue out? [Engage the Student in conversation but come to the point that the lizard also flicks it tongue out]

6. Teacher: Good. Just like the snake, the lizard flicks it tongue out to get information about its environment.

7. Teacher: The weird thing is that humans also have a Jacobson's organ located in our nose, but we no longer use it anymore. We'll get into learning about humans later, though, so let's stick to reptiles for now.

8. Teacher: So, based on what you know about reptiles, what colors do you think most reptiles have on their skin? [Engage the Student in conversation but come to the point that the reptiles are usually dark green, brown, and gray]

9. Teacher: Good, most reptiles are usually darker colors, probably to help them blend into their environment. But there are a few reptiles that have bright colors like yellow, purple, and orange. For example, take a look at this cool looking bright yellow snake. [Show the Student the picture of a yellow snake]

10. Teacher: You want to know something even stranger? Some reptiles can even change the color of their skin, depending on how they feel. For example, this chameleon changes from green to having some spotty patterns on its skin. Check this out. [Click on video below]

11. Teacher: Another thing interesting about reptiles is that some reptiles shed their skin as part of the normal growing up process. Snakes, for example, are known to shed their skin as they grow into bigger snakes. In fact, here's a great video of a snake shedding its skin. [Click on video below]

12. Teacher: And what do you think reptiles eat? Meat, plants, or both? [Engage the Student in conversation but make that point that some reptiles eat only meat, others eat only plants, while still other eat both meat and plants]

13. Teacher: Sorry, that was a trick question. So the answer is all three. Remember what we call animals that eat only meat? We call them carnivores. "Carni" means flesh and "vore" means to devour. How about animals that only eat plants - remember what we call them? We call them herbivores. "Herb" means plant and "vore", well you know what that means. And finally, what do we call animals that eat both meat and plants? We call them omnivores. "Omni" means everything. Hey guess what other kind of animal is an omnivore? Humans!

14. Teacher: So you see, reptiles are carnivores, herbivores and omnivores.

15. Teacher: Now, that we talked about what reptiles eat, let's talk about how reptiles protect themselves from being eaten by other animals. Reptiles usually defend themselves by running away or hiding. But when they cannot do these things, some reptiles do some weird things. Some reptiles, like this video of an Australian frilled lizard, will try to appear larger than they actually are. Check this out. [Click on the video]

16. Teacher: Other reptiles, like snakes, will just roll over on its back and play dead, like this hognose snake: [Click on the video]

17. Teacher: And still, other reptiles, like the spitting cobra, will try to spray venom, a very dangerous poison, into your eyes, making you blind forever. [Click on the video]

18. Teacher: So you see, other than the ordinary ways to fighting like by biting or clawing, reptiles have really neat and different ways of defending themselves, wouldn't you say? [Get positive response from Student]

19. Teacher: Now, one last point before we end today - if you had to guess how reptiles became reptiles, which animals would think reptiles actually came from? I'll give you a hint - it was the same animals that we already covered in one of our lessons. [Engage the Student in conversation but come to the conclusion that reptiles evolved from amphibians]

20. Teacher: That's right, reptiles came from amphibians, and don't you think they look similar? When you have more time, you can see for yourself how amphibians and reptiles are similar, yet different.

21. Teacher: Ok - time for review, stand up and get in front of the class (consider inviting other members of the family also to set the stage). [Get Student’s positive response and ask the following:

1. Is a frog a reptile? Why or why not? A frog is not a reptile, it is an amphibian since frogs don't have scales and need to live in water to survive

2. What do you call the organ that the reptile uses to smell and taste its environment? Jacobson's organ

3. Are reptiles carnivores, herbivores, or omnivores? They are all 3 - some eat only meat, some only plants, and still others eat both.

4. Besides using teeth and claws, what are some of the neat ways that reptiles defend themselves? Any one of the following: 1) make themselves bigger than they really are, 2) play dead, and 3) use venom

5. Which animals did reptiles come from? Amphibians

Next Week's Lesson: Mammals >>