Question 1

Which of the following best describes the cleavage pattern in deuterostome development, as seen in echinoderms?

Accepted Answer

Radial and indeterminate

Question 2

In echinoderms, the blastopore develops into which structure?

Accepted Answer

The anus

Question 3

Which feature is unique to echinoderms and is involved in locomotion, feeding, and gas exchange?

Accepted Answer

Water-vascular system

Question 4

Why have echinoderms not exploited a wide range of habitats and niches compared to other animal phyla?

Accepted Answer

Their pentaradial symmetry and water-vascular system limit their mobility and adaptability

Question 5

Which class of echinoderms includes organisms with a rigid, spiny test and a mouth structure called Aristotle’s lantern?

Accepted Answer

Echinoidea

Question 6

A starfish is observed everting its stomach to digest a mussel outside its body. This feeding strategy is an example of:

Accepted Answer

External digestion

Question 7

Which of the following is a correct sequence for water flow through the water-vascular system of a starfish?

Accepted Answer

Madreporite → Ring canal → Radial canal → Tube feet

Question 8

Which echinoderm class is characterized by a flexible, elongated body and the ability to expel internal organs as a defense mechanism?

Accepted Answer

Holothuroidea

Question 9

What is the main function of tube feet in echinoderms?

Accepted Answer

Locomotion and feeding

Question 10

Which of the following statements about echinoderm nervous systems is correct?

Accepted Answer

They have a nerve ring and radial nerves but lack a true brain

Question 11

A sea urchin’s mouth contains five calcium carbonate teeth used for grazing algae. This structure is known as:

Accepted Answer

Aristotle’s lantern

Question 12

Which of the following best explains why echinoderms can regenerate lost arms or body parts?

Accepted Answer

They have indeterminate cleavage during development

Question 13

Which of the following is NOT a characteristic of all echinoderms?

Accepted Answer

Presence of a notochord

Question 14

In protostome development, which of the following is true?

Accepted Answer

Cleavage is spiral and determinate

Question 15

Which echinoderm class includes organisms that are flattened and burrow in sand, such as sand dollars?

Accepted Answer

Echinoidea

Question 16

A brittle star loses one of its arms to a predator. What is the most likely outcome?

Accepted Answer

It will regenerate the lost arm over time

Question 17

Which of the following best describes the coelom formation in deuterostomes?

Accepted Answer

Mesoderm buds from the wall of the archenteron to form the coelom

Question 18

Which of the following is a real-world example of the ecological role of sea cucumbers?

Accepted Answer

They recycle nutrients by ingesting and excreting sediment

Question 19

Which of the following equations best represents the relationship between the number of arms (n) and the number of radial canals in a typical starfish?

Accepted Answer

$$n = 5$$

Question 20

Which of the following adaptations allows feather stars (crinoids) to capture food particles from the water?

Accepted Answer

Tube feet on flexible arms

Phylum Echinodermata: Structure, Development, and Diversity

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