What is an Invertebrate?

Invertebrates are animals without a backbone, comprising over 30 phyla with diverse characteristics. They range from those with hard exoskeletons to soft-bodied species relying on water for support. Arthropods, including insects and crustaceans, are the largest phylum. Mollusks, such as slugs, snails, squid, and octopuses, have a mantle, sometimes forming a shell. Sponges, the simplest invertebrates, lack organs and systems, using water flow for sustenance. The term 'invertebrates' is a convenient way to refer to all species without a backbone.

What characteristic is common to all invertebrates?

• They are all microscopic.

• They lack a backbone.

• They have a hard exoskeleton.

• They have a backbone.

Which phylum contains more species than all other phyla combined?

• Chordata

• Mollusca

• Arthropodia

• Periphera

What is a unique feature of mollusks?

• They have no organs.

• They are all aquatic.

• They have a mantle.

• They have a backbone.

How do sponges obtain food?

• By hunting small fish.

• Through photosynthesis.

• By filtering water through their bodies.

• By absorbing nutrients from the soil.

What does the term 'invertebrates' refer to?

• Animals without a backbone.

• Animals with a backbone.

• Animals that live in water.

• A group of animals with shared characteristics.