Question 1

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

Accepted Answer

Asymmetrical

Question 2

What is the primary function of choanocytes in sponges?

Accepted Answer

Capturing and digesting food particles

Question 3

Which of the following is NOT a characteristic of Phylum Cnidaria?

Accepted Answer

Bilateral symmetry

Question 4

Cnidarians possess specialized cells called cnidocytes. What is the main function of these cells?

Accepted Answer

Capturing prey and defense

Question 5

Which of the following correctly matches the cnidarian class with its dominant life stage?

Accepted Answer

Scyphozoa – Medusa

Question 6

Which structure in sponges is responsible for providing support and can be composed of silica or calcium carbonate?

Accepted Answer

Spicules

Question 7

A marine biologist discovers a new animal with the following features: no true tissues, filter feeding, and a skeleton made of spicules. To which phylum does this animal most likely belong?

Accepted Answer

Porifera

Question 8

Which of the following statements about the evolutionary relationship between choanoflagellates and sponges is correct?

Accepted Answer

Sponges evolved from choanoflagellate-like ancestors

Question 9

Which of the following best explains why sponges are considered basal animals?

Accepted Answer

They lack true tissues and organs

Question 10

A student observes a cnidarian with only a polyp stage and no medusa stage. To which class does this organism most likely belong?

Accepted Answer

Anthozoa

Question 11

Which of the following is a key difference between the body plans of sponges and cnidarians?

Accepted Answer

Cnidarians are diploblastic, sponges lack true tissues

Question 12

Which of the following best describes the feeding mechanism of sponges?

Accepted Answer

Filter feeding using choanocytes

Question 13

Which of the following is a real-world application of understanding sponge spicules?

Accepted Answer

Designing lightweight, strong materials for engineering

Question 14

Which of the following equations best represents the relationship between surface area ($$A) $$and volume ($$V) $$for a spherical sponge, and why is this relationship important for sponge physiology?

Accepted Answer

$$A = 4\pi r^2$, V$$ = \frac{4}{3}\pi $$r^3$$; a high surface area to volume ratio facilitates efficient filter feeding

Question 15

Which of the following is a correct statement about the evolutionary significance of the gastrovascular cavity in cnidarians?

Accepted Answer

It allows for extracellular digestion, a key step in animal evolution

Question 16

A researcher is studying a coral reef and finds that the corals are dying due to increased water temperature. Which feature of cnidarians makes them particularly sensitive to environmental changes?

Accepted Answer

Their reliance on symbiotic algae for energy

Question 17

Which of the following best explains why sponges are considered to be at the base of the animal phylogenetic tree?

Accepted Answer

They lack true tissues and organs, resembling ancestral protists

Question 18

Which of the following is a plausible reason why the medusa stage is more prominent in Scyphozoa than in Anthozoa?

Accepted Answer

The medusa stage allows for greater dispersal of offspring in open water

Question 19

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

Accepted Answer

They transport nutrients and produce spicules

Question 20

Which of the following is a key adaptation that allowed some invertebrates to colonize land?

Accepted Answer

Evolution of protective outer coverings to prevent desiccation

Animal Diversity II: Basal Animals – Porifera and Cnidaria

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