Question 1

Which of the following is a defining developmental feature of deuterostomes?

Accepted Answer

The anus forms from the blastopore during gastrulation.

Question 2

Which group is most closely related to vertebrates within the deuterostomes?

Accepted Answer

Cephalochordata

Question 3

What is the primary function of the water vascular system in echinoderms?

Accepted Answer

Locomotion, nutrient distribution, and gas exchange

Question 4

Which of the following statements about echinoderm symmetry is correct?

Accepted Answer

Echinoderm larvae are bilaterally symmetrical, but adults exhibit pentameral symmetry.

Question 5

Which of the following is NOT a derived character shared by all chordates?

Accepted Answer

Amniotic egg

Question 6

During the Cambrian Explosion, what major evolutionary event occurred?

Accepted Answer

A rapid increase in species richness and morphological diversity

Question 7

Which of the following clades contains the greatest number of extant vertebrate species?

Accepted Answer

Actinopterygii (ray-finned fishes)

Question 8

What is the main structural component of the echinoderm endoskeleton?

Accepted Answer

Calcium carbonate ossicles

Question 9

Which of the following best describes the evolutionary relationship between sea stars and mammals?

Accepted Answer

They are both deuterostomes and share a common ancestor more recently than with other invertebrates.

Question 10

Which fossil locality is famous for preserving soft-bodied Cambrian organisms, including early chordates?

Accepted Answer

Burgess Shale

Question 11

Which of the following is true about the distribution of echinoderms?

Accepted Answer

They are exclusively marine and found at all depths, from intertidal zones to the abyssal zone.

Question 12

Which of the following is a correct statement about vertebrate evolution?

Accepted Answer

Vertebrates have existed for over half a billion years.

Question 13

Which of the following is a function of the tube feet in echinoderms?

Accepted Answer

Locomotion and feeding

Question 14

Which of the following best explains why echinoderms have a good fossil record?

Accepted Answer

Their mineralized endoskeletons are readily preserved as fossils.

Question 15

Which of the following is NOT a member of the deuterostome clade?

Accepted Answer

Earthworm

Question 16

Which of the following is a correct statement about the phylogeny of Metazoa?

Accepted Answer

Some invertebrates, such as echinoderms, are more closely related to vertebrates than to other invertebrates.

Question 17

Which of the following is a derived character of vertebrates?

Accepted Answer

Vertebrae enclosing a spinal cord

Question 18

Which equation best represents the timeline of vertebrate evolution, given that the earliest vertebrate fossils are about 525 million years old?

Accepted Answer

$$	ext{Age of vertebrate clade} \approx 525 	ext{ million years}$$

Question 19

Which of the following is a correct statement about the water vascular system in echinoderms?

Accepted Answer

It is a network of water-filled tubes used for locomotion, nutrient distribution, and gas exchange.

Question 20

Which of the following best describes the evolutionary significance of the Burgess Shale?

Accepted Answer

It preserves soft-bodied organisms, revealing anatomical structures that are usually lost in the fossil record.

Deuterostomes: Introduction and Fishes

Study Guide - Practice Questions