Elementary School Science

Input:
What is the most important content in this lesson?
To reach this lesson’s objective, students need to understand:

• The difference between vertebrates and invertebrates.

• Distinct characteristics of vertebrates and invertebrates.

• The characteristics of each vertebrate group: mammal, reptile, amphibian, bird, and fish.

• The characteristics of each invertebrate group: cnidarian, sponges, arthropods, mollusks, echinoderm, and annelids/worms.

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How will the learning of this content be facilitated?

• On the board, draw two columns, but do not label them. Tell yourself that the first column will be the “invertebrate” column and the second column will be “vertebrate” column. The point of this activity is to separate animals by vertebrates and invertebrates, but to let the students figure out how the characteristic of these animals on their own before telling them about the two groups.

• Go around the room and ask each student to give you the name of an animal or an insect. As the students give you the name of the animal or insect, place it in the correct column. Once all of the students have provided an animal or an insect, tell them to look at both columns. Ask the students the following questions:

  • What do you notice about the first column? What do they have in common?

  • What do you notice about the second column? What do they have in common?

**The students will most likely tell you that the first column contains a list of bugs, while the second column contains a list of animals. Even though bugs are considered animals, many students will separate them as such.**

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• Explain to the students that the first column contains invertebrates; the second column contains vertebrates. Explain the main difference between the two groups:

• Invertebrates do not have a backbone and are generally smaller in size. Examples of invertebrates include, insects, squids, and worms.

• Vertebrates have a backbone and are generally large in size. Examples of vertebrates include, humans, lizards, and birds.

Scientists use different characteristics to classify/ group animals. One of the ways scientists classify animals are as vertebrates and invertebrates. Explain that today, the students will be learning about vertebrates and invertebrates and the way they are classified/grouped.

• The teacher will hand out the “Vertebrates and Invertebrates: What’s the Difference?” worksheet. If it is possible, project the “Vertebrates and Invertebrates: What’s the Difference?” onto the board using a projector or put into a PowerPoint document and project so that the teacher can point to each section as they explain. Students will fill in their worksheet as each section is described. From this activity, the students will learn the differences between vertebrates and invertebrates.

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• The teacher should begin by explaining the “vertebrates” category. **A teacher’s copy of the worksheet that should be projected is provided at the end of the lesson. The information listed below provides more details that should be taught to the students while explaining the worksheet.**

• Vertebrates: vertebrates have a well-developed internal skeleton. The skeleton is made of vertebrates, which is how organisms with this characteristic got the name “vertebrates.” In addition to the well-developed internal skeleton, vertebrates also have a highly developed brain, nervous system, circulatory system, respiration system, and cells that cover the outside of their body. Think about birds—they have feathers on the outside of their body. Humans have skin; fish have scales. Vertebrates tend to be large in size as compared to invertebrates. This is due to the well-developed internal skeleton that allows for the vertebrates to stand up straight and carry more weight. Vertebrates are classified into five groups: mammals, reptiles, amphibians, birds, and fish. Vertebrates are also grouped as either warm-blooded or cold-blooded. Warm-blooded vertebrates can control their body temperature regardless of the outside temperature. Examples include dogs, cats, and humans. Cold-blooded vertebrates cannot control their body temperature; the outside temperature affects their body temperature. Examples include frogs, fish, and snakes. Vertebrates live in various habitats, but can accommodate more easily than invertebrates. 2% of all animal species are vertebrates.

• Invertebrates: invertebrates do not have a well-developed internal skeleton or internal systems. Instead, many invertebrates are filled with fluid—think about jellyfish and worms. Other invertebrates have a hard shell covering their body-think about crabs and snails. Invertebrates are small, due to the lack of the skeleton and muscular system. Since invertebrates are small, there are two different body plans. The first body plan is radial symmetry- circular shape around a mouth. Organisms with this shape live most of their life stationed in one place. The second body plan is bilateral symmetry- left and right halves that are exactly the same with a definite front and back end. Organisms with this shape live most of their life searching for food. Invertebrates are not as intelligent as vertebrates. They have a simple nervous system and live by trusting their instincts. Invertebrates can repeatedly do something that is bad for them and never learn that what they are doing is harmful. Invertebrates are classified into six groups: cnidarian, sponges, arthropods, mollusks, echinoderms, annelids/worms. Invertebrates are found in all habitats, but generally have a hard time adapting to a habitat that is out of their own. There are two million species of animals in the world, with 98% of them being invertebrates.

**As a way to help the students remember the difference between the two groups, tell the students that the prefix “in” means “without” (invertebrate = without vertebrates/ backbone)**

 

Information Sources:

http://www.kidport.com/reflib/science/animals/animalindexinv.htm

http://www.ducksters.com/animals/invertebrates.php

http://www.encyclopedia.com/topic/Invertebrates.aspx

http://www.diffen.com/difference/Invertebrate_vs_Vertebrate

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• The teacher will expand on this topic by explaining the five groups of vertebrates. The teacher will hand out the worksheet “Classifying Vertebrates”.  If it is possible, project the “Classifying Invertebrates & Vertebrates” worksheet onto the board using a projector or put into a PowerPoint document and project so that the teacher can point to each section as they explain. Students will fill in their worksheet as each group is described. From this activity, the students will learn the characteristic of each group of invertebrates and vertebrates. Tell the students that you will begin on the side that says “Vertebrates”.

**A teacher’s copy of the worksheet that should be projected is provided at the end of the lesson. The information listed below is the same information provided on the worksheet**

• Mammals: warm-blooded; have fur or hair; give birth to live young; nurse their young

• Amphibians: cold-blooded; can live on land or in the water; lay eggs; have moist skin and webbed feet

• Reptiles: cold-blooded; have scales and dry skin; lay eggs

• Birds: warm-blooded; have feathers and fur; lay eggs

• Fish: cold-blooded; live in water; have scales and fins; have gills instead of lungs; lay eggs

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Information Source:

https://www.sheppardsoftware.com/content/animals/kidscorner/classification/kc_class_again.htm]

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• Once the vertebrates side is explained, tell the students to flip the worksheet over to the side that says “Invertebrates”.

• Cnidarian: live in water; have tentacles; take in their food through a central location on their body

• Sponges: simple form of invertebrates; live in water; filter food from the water they live

• Arthropods: can live on the land, in water, or in the air; have legs; examples include spiders and crabs

• Mollusks: have a muscular foot; can live on land or in the water; examples include clams and snails

• Echinoderms: live only in the water; take in their food through a central location on their body; examples include starfish and sea cucumbers

• Annelids/Worms: can live on land or in the water; usually fluid or jelly-filled; do not have legs or arms

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Information Source

https://quizlet.com/852213/6-groups-of-invertebrates-flash-cards/]

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• After the diagram is explained, the students will participate in the activity “Animals All Over”. On desks throughout the room, there will be different animal habitats set up. Each habitat will be labeled and pictures of different animals will be provided for the students to look at. Each student will have an “Animals All Over” worksheet. Students will work in groups of three and travel around to each habitat. The students will look at the pictures of the animals. They will first decide if the animal is a vertebrate or an invertebrate and then decide what group they are in. Allow the students to use their worksheets from class. The students will have about 15 minutes to complete the activity. Once the students have completed the activity, they will reconvene at their desks and the teacher will review the answers.

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• The final assessment will be for the students to answer the question:

Think about what you learned in class today about vertebrates and invertebrates. What is the main difference between vertebrates and invertebrates? Why do vertebrates tend to be larger in size than invertebrates? Why do you think there are more species of invertebrates than vertebrates?