Question 1

Which lineage of Echinoderms is made up of about 600 living species of sea lilies and feather stars?

Accepted Answer

The lineage of Echinoderms consisting of sea lilies and feather stars is known as Crinoidea. This group is made up of around 600 species, which are notable for their delicate, branching arms and attachment to the seafloor via a stalk.

Question 2

Which subphylum includes the sea squirts?

Accepted Answer

Sea squirts belong to the subphylum Urochordata, which includes tunicates or sea squirts.

Question 3

Which term refers to a small muscular bulb in the sea star's foot that contracts and forces fluid into the tube foot?

Accepted Answer

The small muscular bulb in the sea star's foot that contracts and forces fluid into the tube foot is called an ampulla. The ossicle refers to the small calcium carbonate plates that make up the sea star's endoskeleton. The radial canal and ring canal are part of the sea star's water vascular system, but they do not specifically refer to the structure responsible for pumping fluid into the tube foot.

Question 4

Which lineage of Echinoderms is made up of about 1500 species of sea cucumbers, which are elongated along their oral-aboral axis?

Accepted Answer

The lineage of Echinoderms that is made up of about 1500 species of sea cucumbers, which are elongated along their oral-aboral axis, is Holothuroidea.

Question 5

Which lineage of Echinoderms is made up of about 2000 species of brittle stars and basket stars, each with elongated, slender, somewhat snakelike arms surrounding a well-defined central disk?

Accepted Answer

The description matches the characteristics of the Ophiuroidea lineage, which includes brittle stars and basket stars with elongated, slender, snakelike arms and a central disk. The other lineages of Echinoderms, such as Echinoidea, Holothuroidea, and Crinoidea, have different body plans and features.

Question 6

Which phylum has a unique water vascular system that usually includes tube feet that can be used for movement?

Accepted Answer

The Echinodermata phylum includes animals such as sea stars, sea urchins, and sea cucumbers that have a unique water vascular system which helps them move and captures food. This system is made up of a network of fluid-filled canals and tube feet that operate through muscular contraction.

Question 7

What is the name of the mesoderm-derived, calcium-stiffened structures that comprise the internal skeleton of echinoderms?

Accepted Answer

The mesoderm-derived, calcium-stiffened structures that comprise the internal skeleton of echinoderms are called ossicles. Ampullae are bulb-like structures that control the movement of tube feet in echinoderms, madreporites are plates that regulate water flow and gas exchange in echinoderms, and radial canals are part of the water-vascular system in echinoderms that distribute water to the tube feet.

Question 8

Members of which phylum are called acorn worms?

Accepted Answer

Acorn worms are members of the phylum Hemichordata.

Question 9

Which phylum includes members that have, at some point during their development, a hollow dorsal nerve cord?

Accepted Answer

Members of the phylum Chordata all have, at some point during their development, a hollow dorsal nerve cord. This is a defining characteristic of the phylum, which includes both invertebrate (such as lancelets and tunicates) and vertebrate (such as fish, amphibians, reptiles, birds, and mammals) groups.

Question 10

Which cells are unique to vertebrates?

Accepted Answer

Neural crest cells are unique to vertebrates and play a critical role in the development of many vertebrate structures, including the nervous system, head and facial features, and pigment cells. Pharyngeal cells are found in both vertebrates and invertebrates, notochordal cells are found in both vertebrates and some invertebrates, and oral hood cells are specific to certain invertebrates.

Question 11

What is the structure through which water enters the water vascular system of a sea star?

Accepted Answer

The madreporite is a porous plate located on the aboral surface of a sea star through which sea water enters the water vascular system.

Question 12

What forms the skeleton of invertebrate chordates?

Accepted Answer

The notochord forms the primary support structure in invertebrate chordates, serving as the precursor to the vertebral column found in vertebrate chordates. The pharynx and oral hood are structures found in many invertebrates, but they do not form the skeleton. The neural crest is a group of cells that give rise to various structures in vertebrates, but it is not part of the skeleton in invertebrate chordates.

Question 13

Which phylum includes members that have bilaterally symmetrical larvae but exhibit secondary radial symmetry as adults, usually organized around five rays, or "arms"?

Accepted Answer

Echinodermata includes members that have bilaterally symmetrical larvae but exhibit secondary radial symmetry as adults, usually organized around five rays, or "arms".

Question 14

Which of the following lineages contains all of the other lineages in the list?

Accepted Answer

Vertebrata is the most inclusive lineage, containing all the other lineages in the list.

Question 15

What part of the chordate digestive system is positioned just posterior to the mouth?

Accepted Answer

The pharynx is located just posterior to the mouth in the chordate digestive system. It serves as both a passageway for food and as a site for gas exchange in some aquatic chordates.

Question 16

Which of the following morphological innovations is found in the ancestor that led to vertebrates?

Accepted Answer

The notochord, a flexible rod-like structure, is a defining feature of the chordates, the phylum that includes vertebrates. This innovation likely played a role in the evolution of the vertebrate backbone, but true vertebrae did not evolve until later in vertebrate history. Bone and neural crest cells are also important innovations in vertebrates, but they emerged later in the evolutionary lineage.

Question 17

Which lineage of Echinoderms is made up of about 1500 species of sea stars, each with a central disk surrounded by 5 to 20 "arms"?

Accepted Answer

The lineage of Echinoderms made up of about 1500 species of sea stars, each with a central disk surrounded by 5 to 20 "arms" is Asteroidea. Ophiuroidea are brittle stars, Crinoidea are feather stars or sea lilies, and Echinoidea are sea urchins and sand dollars.

Question 18

Which of the following surrounds and protects the brain in all vertebrates?

Accepted Answer

The cranium is the bony structure that surrounds and protects the brain in all vertebrates. The oral hood, notochord, and pharynx are all structures related to the digestive system or embryonic development, but they do not protect the brain.

Question 19

Which lineage includes members called lancelets?

Accepted Answer

Lancelets are members of the lineage Cephalochordata, which includes small, fish-like marine animals that are filter-feeders and have a notochord that runs the length of their body.

Question 20

Which lineage of Echinoderms is made up of about 950 species of sea urchins and sand dollars, which have their ossicles fused into solid tests that restrict flexibility but provide excellent protection?

Accepted Answer

The lineage of Echinoderms consisting of sea urchins and sand dollars is called Echinoidea. These organisms have their ossicles fused into solid tests, which restrict their flexibility but provide superior protection. There are around 950 species of sea urchins and sand dollars in the Echinoidea lineage.

Quiz 28: Diversity of Animals 2: Deuterostomes: Vertebrates and Their Closest Relatives