Question 1

Which of the following best describes the embryonic development of sponges (Phylum Porifera)?

Accepted Answer

They are monoblastic, developing from a single germ layer.

Question 2

A marine biologist observes an aquatic animal that is sessile, lacks tissues and organs, and has an asymmetrical body plan. Which group does this organism most likely belong to?

Accepted Answer

Porifera (sponges)

Question 3

Which of the following statements about the nervous systems of sponges and cnidarians is correct?

Accepted Answer

Sponges lack a nervous system, while cnidarians possess a nerve net.

Question 4

How do sponges primarily obtain their food and energy?

Accepted Answer

By filtering prokaryotes, protists, and organic matter from water currents.

Question 5

Which of the following is a key ecological role of sponges in aquatic ecosystems?

Accepted Answer

They act as decomposers, increasing nutrient cycling and supporting biodiversity.

Question 6

Cnidarians are considered secondary consumers because they:

Accepted Answer

Use cnidocytes to capture and consume other animals.

Question 7

Which of the following best explains why coral reefs are considered 'ecosystem engineers'?

Accepted Answer

They create complex structures that increase habitat diversity and support high biodiversity.

Question 8

A student claims that all animals have tissues and organs. Which of the following best refutes this claim?

Accepted Answer

Sponges (Phylum Porifera) lack true tissues and organs.

Question 9

Which of the following reproductive strategies is found in both sponges and cnidarians?

Accepted Answer

Both can reproduce asexually and sexually.

Question 10

A coral reef is experiencing bleaching due to increased water temperatures. Which of the following is a likely consequence for human well-being?

Accepted Answer

Loss of biodiversity and reduced fishery resources, impacting food security.

Question 11

Which of the following best describes the body symmetry of cnidarians?

Accepted Answer

Radial symmetry

Question 12

Which of the following is a unique feature of cnidarians that allows them to capture prey?

Accepted Answer

Cnidocytes (stinging cells)

Question 13

A researcher is studying an aquatic animal that can reproduce by fragmentation and also by releasing sperm into the water. Which group is this animal most likely from?

Accepted Answer

Porifera (sponges)

Question 14

Which of the following best explains why sponges are restricted to aquatic environments?

Accepted Answer

Their feeding and reproductive strategies depend on water currents.

Question 15

Which of the following is a plausible consequence of human-generated pollution on coral reefs?

Accepted Answer

Decline in coral abundance, leading to reduced ecosystem services for humans.

Question 16

Which of the following best describes the movement abilities of sponges and cnidarians?

Accepted Answer

Sponges are sessile, while cnidarians can move by muscle cell contractions.

Question 17

Which of the following is true regarding the germ layers in animal embryonic development?

Accepted Answer

Sponges are monoblastic, while cnidarians are diploblastic.

Question 18

A scientist is comparing the ecological roles of sponges and corals. Which of the following statements is correct?

Accepted Answer

Sponges act as decomposers, while corals act as ecosystem engineers.

Question 19

Which of the following best explains the impact of coral reefs on marine biodiversity?

Accepted Answer

Coral reefs increase biological production and biodiversity by providing complex habitats.

Question 20

Which of the following equations best represents the relationship between biodiversity ($B$), nutrient cycling rate ($N$), and sponge abundance ($S$) in an aquatic ecosystem, based on their ecological roles?

Accepted Answer

$B = k 	imes N 	imes S$

Animals: Sponges and Cnidarians – Structure, Function, and Ecological Roles

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