$$\text{Surface Area} \propto \text{Volume}^{2/3}$$; this allows efficient diffusion across the body surface.

$$\text{Growth} = \text{Old Cuticle Shed} + \text{New Cuticle Formed}$$

Question 1

Which of the following statements best describes the body plan of sponges (Phylum Porifera)?

Accepted Answer

Sponges have a sac-like body perforated with pores and lack true tissues.

Question 2

Which cell type in sponges is responsible for creating water currents and capturing food particles?

Accepted Answer

Choanocytes

Question 3

Cnidarians are characterized by which of the following features?

Accepted Answer

Diploblastic development and radial symmetry

Question 4

Which structure in cnidarians functions as both the mouth and anus?

Accepted Answer

Gastrovascular cavity opening

Question 5

A coral reef is primarily formed by which group of cnidarians, and what is their ecological significance?

Accepted Answer

Anthozoans; they create rocklike reefs that support diverse marine life

Question 6

Which of the following best explains why flatworms (Platyhelminthes) are able to eliminate nitrogenous waste and exchange gases by diffusion?

Accepted Answer

Their dorsoventrally flattened body increases surface area, placing all cells close to water.

Question 7

Which equation represents the relationship between surface area and volume for a flattened organism, and why is this important for flatworms?

Accepted Answer

$$	ext{Surface Area} \propto 	ext{Volume}^{2/3}$$; this allows efficient diffusion across the body surface.

Question 8

Tapeworms lack a mouth and gastrovascular cavity. How do they obtain nutrients?

Accepted Answer

They absorb nutrients directly from the host's intestine through their body surface.

Question 9

Which of the following is a unique feature of rotifers that distinguishes them from many other invertebrates?

Accepted Answer

They possess an alimentary canal with two openings.

Question 10

Which phylum includes animals with a segmented body, hard exoskeleton, and jointed appendages, and what is the main component of their exoskeleton?

Accepted Answer

Arthropoda; chitin

Question 11

Which equation best describes the process of ecdysis (molting) in ecdysozoans?

Accepted Answer

$$	ext{Growth} = 	ext{Old Cuticle Shed} + 	ext{New Cuticle Formed}$$

Question 12

Which of the following best explains the evolutionary advantage of insect flight?

Accepted Answer

Flight allows insects to evade predators, locate food and mates, and disperse to new habitats.

Question 13

Which developmental characteristic is shared by all deuterostomes?

Accepted Answer

Formation of the anus from the blastopore before the mouth.

Question 14

Echinoderms possess a water vascular system. What is its primary function?

Accepted Answer

Locomotion and feeding

Question 15

Which equation represents the relationship between the number of planes of symmetry and the type of symmetry in animals?

Accepted Answer

$$	ext{Radial Symmetry}: n \geq 2$$; $$	ext{Bilateral Symmetry}: n = 1$$

Question 16

Which of the following is a real-world consequence of coral reef destruction?

Accepted Answer

Loss of habitat for many marine species and decreased biodiversity.

Question 17

Which of the following best describes the difference between polyps and medusae in cnidarians?

Accepted Answer

Polyps are sessile and adhere to substrates, while medusae are free-swimming with a bell-shaped body.

Question 18

Which phylum is most closely related to chordates, based on evolutionary history?

Accepted Answer

Echinodermata

Question 19

Which of the following is a function of amoebocytes in sponges?

Accepted Answer

Digest food, transport nutrients, and produce skeletal fibers

Invertebrates: Diversity, Structure, and Evolution

Study Guide - Practice Questions