3rd grade interactive video Unit 2 lesson 3

What is a key characteristic of vertebrates?

• They have an exoskeleton.

• They have a backbone.

• They are always cold-blooded.

• They live only in water.

What is the primary function of a backbone in animals?

• To help with digestion.

• To regulate body temperature.

• To protect the spinal cord.

• To aid in camouflage.

Which of the following animals is NOT explicitly mentioned as having a backbone in the video?

• Hippopotamus

• Egret

• Snake

• Spider

What percentage of all animal species on Earth are invertebrates?

• Less than 5%

• Approximately 25%

• Exactly 50%

• More than 95%

What is a key difference between insects and other animal groups like amphibians, mammals, birds, fish, and reptiles?

• Insects are the only invertebrates.

• Insects are the largest group of invertebrates, outnumbering all listed vertebrates combined.

• Insects have backbones.

• Insects are the smallest group of animals.

What is a common characteristic of animals without backbones, such as insects, arachnids, and crustaceans?

• They have an internal skeleton.

• They have a flexible internal skeleton.

• They have an external hard body covering.

• They are all soft-bodied.

How can insects be distinguished from arachnids?

• Insects have 8 legs and 2 body parts, while arachnids have 6 legs and 3 body parts.

• Insects have 6 legs and 3 body parts, while arachnids have 8 legs and 2 body parts.

• Insects have an exoskeleton, while arachnids do not.

• Insects are always larger than arachnids.

Which of the following are examples of crustaceans?

• Spiders and scorpions

• Snails and jellyfish

• Shrimp, lobsters, and crabs

• Earthworms and sea stars