Question 1

Which of the following best describes the function of choanocytes in sponges?

Accepted Answer

They generate water flow and capture food particles via phagocytosis.

Question 2

In the life cycle of a typical cnidarian, which stage is responsible for sexual reproduction?

Accepted Answer

Medusa

Question 3

Which structure in cnidarians is responsible for the discharge of a stinging thread used in prey capture?

Accepted Answer

Cnidocyte

Question 4

A student observes a cross-section of a hydra and notes two tissue layers separated by a gelatinous substance. What are these layers and the substance called?

Accepted Answer

Epidermis, mesoglea, and gastrodermis

Question 5

Which of the following best explains why sponges are considered filter feeders?

Accepted Answer

They draw water through pores, trapping food particles with choanocytes.

Question 6

In the nervous system of invertebrates, which organism is characterized by a nerve net rather than a centralized brain?

Accepted Answer

Hydra

Question 7

Which of the following is a key difference between the polyp and medusa forms in cnidarians?

Accepted Answer

Polyps are typically sessile and cylindrical, while medusae are free-swimming and bell-shaped.

Question 8

A scientist is studying the movement of Hydra. Which term best describes the unique way Hydra moves?

Accepted Answer

Somersaulting

Question 9

Which of the following statements about the Anthozoa class is correct?

Accepted Answer

Anthozoans have a well-developed pharynx and septa within the gastrovascular cavity.

Question 10

Which of the following best describes the function of amoebocytes in sponges?

Accepted Answer

They digest and transport nutrients, and produce spicules.

Question 11

In the life cycle of Aurelia (a scyphozoan jellyfish), which stage is responsible for producing medusae asexually?

Accepted Answer

Strobila

Question 12

Which of the following is a correct sequence of water flow through a sponge?

Accepted Answer

Pores → Spongocoel → Osculum

Question 13

Which of the following best explains the evolutionary advantage of radial symmetry in cnidarians?

Accepted Answer

It enables the organism to sense and respond to stimuli from all directions equally.

Question 14

Which structure in the scyphozoan life cycle is responsible for sexual reproduction?

Accepted Answer

Medusa

Question 15

A marine biologist finds an organism with a single opening serving as both mouth and anus, tentacles, and a gastrovascular cavity. To which group does this organism most likely belong?

Accepted Answer

Cnidaria

Question 16

Which of the following is NOT a function of the gastrovascular cavity in cnidarians?

Accepted Answer

Production of gametes

Question 17

Which of the following best describes the nervous system of a starfish?

Accepted Answer

A radial nerve system with a nerve ring

Question 18

Which of the following is a correct statement about the function of nematocysts?

Accepted Answer

They are used for prey capture and defense in cnidarians.

Question 19

Which of the following best explains why the medusa stage is important in the life cycle of many cnidarians?

Accepted Answer

It is adapted for dispersal and sexual reproduction.

Question 20

A student is asked to compare the nervous systems of a grasshopper and a hydra. Which of the following is a correct comparison?

Accepted Answer

The grasshopper has a ventral nerve cord and brain, while the hydra has a nerve net.

Structure, Function, and Life Cycles of Sponges and Cnidarians

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