Invertebrates Flashcard

Front

What is a defining characteristic of invertebrates?

Back

They are ectotherms.

Answer explanation

Invertebrates are characterized by the absence of a backbone. While many are ectotherms, the defining trait is their lack of a backbone, making the correct answer 'They are ectotherms' misleading in this context.

Front

Which of the following is true about invertebrates?

Back

They never have a notochord.

Answer explanation

Invertebrates are defined as animals without a backbone. They do not possess a notochord, which is a characteristic of chordates. Therefore, the statement "They never have a notochord" is true.

Front

What characteristic is unique to sponges in the phylum Porifera?

Back

No symmetry

Answer explanation

Sponges, belonging to the phylum Porifera, are unique in having no symmetry. Unlike organisms with radial or bilateral symmetry, sponges have an irregular shape, making 'no symmetry' the correct characteristic.

Front

How do sponges in the phylum Porifera obtain food and oxygen?

Back

Through pores

Answer explanation

Sponges in the phylum Porifera obtain food and oxygen through pores in their bodies. Water flows through these pores, allowing sponges to filter out nutrients and oxygen from the water.

Front

What type of symmetry do cnidarians possess?

Back

Radial symmetry

Answer explanation

Cnidarians exhibit radial symmetry, meaning their body parts are arranged around a central axis. This allows them to interact with their environment from all directions, which is characteristic of their body plan.

Front

What is the function of cnidocytes in cnidarians?

Back

Capturing food

Answer explanation

Cnidocytes are specialized cells in cnidarians that contain nematocysts, which are used to capture food. These cells help immobilize prey, making them essential for the feeding process.

Front

Which of the following is NOT a characteristic of cnidarians? Stinging cells, Radial symmetry, Bilateral symmetry, Marine habitat

Back

Bilateral symmetry

Answer explanation

Bilateral symmetry is NOT a characteristic of cnidarians, which typically exhibit radial symmetry. Cnidarians are known for their stinging cells and primarily inhabit marine environments.

Front

What type of symmetry do worms generally have?

Back

Bilateral symmetry

Answer explanation

Worms exhibit bilateral symmetry, meaning their body can be divided into two equal halves along a single plane. This type of symmetry is common in many animals, allowing for streamlined movement and organization of body structures.

Front

Which phylum do flatworms belong to?

Back

Platyhelminthes

Answer explanation

Flatworms are classified under the phylum Platyhelminthes, which is characterized by their flat bodies and lack of a coelom. This distinguishes them from other phyla like Nematoda and Annelida.

Front

Which group of worms is characterized by having a segmented body?

Back

Segmented worms

Answer explanation

Segmented worms, also known as annelids, are characterized by their segmented bodies, which differentiate them from flatworms and roundworms that have unsegmented bodies. Cnidarians are a separate group entirely.