Question 1

Which of the following characteristics is shared by all animals, distinguishing them from other eukaryotes?

Accepted Answer

Multicellularity with an extensive extracellular matrix

Question 2

The Cambrian explosion is significant in the history of life on Earth because:

Accepted Answer

It is the period when most major animal groups first appear in the fossil record

Question 3

Which of the following is NOT a benefit humans derive from animals, as described in the study materials?

Accepted Answer

Production of oxygen via photosynthesis

Question 4

Which group is considered the closest living relative to animals, based on both morphological and molecular evidence?

Accepted Answer

Choanoflagellates

Question 5

Sponges are considered basal animals because:

Accepted Answer

They are the earliest animals to appear in the fossil record

Question 6

Which of the following statements about animal embryonic tissue layers is correct?

Accepted Answer

Triploblasts have three germ layers: ectoderm, endoderm, and mesoderm

Question 7

Which of the following best describes the evolutionary advantage of bilateral symmetry and cephalization in animals?

Accepted Answer

It concentrates sensory organs and neurons at one end, facilitating directional movement and environmental sensing

Question 8

The coelom in animals provides which of the following functions?

Accepted Answer

A space for oxygen and nutrients to circulate and for internal organs to move independently

Question 9

During embryonic development, the blastopore becomes the anus in which group of animals?

Accepted Answer

Deuterostomes

Question 10

Which of the following is a correct statement about segmentation in animals?

Accepted Answer

Segmentation is a division of the body into a series of similar structures and is found in annelids, arthropods, and vertebrates

Question 11

Which of the following feeding strategies is correctly matched with its description?

Accepted Answer

Deposit feeders: collect food particles from the substrate

Question 12

Which type of skeleton is found in arthropods and provides support from outside the body?

Accepted Answer

Exoskeleton

Question 13

Why is sexual reproduction favored by natural selection in variable or unfavorable environments?

Accepted Answer

It leads to greater genetic diversity, increasing the chances of survival under changing conditions

Question 14

Which of the following is true about viviparous animal species?

Accepted Answer

They give birth to live young, with embryos nourished inside the body

Question 15

Metamorphosis in animal life cycles is best described as:

Accepted Answer

A drastic change from one developmental stage to another, often involving a larval stage that differs from the adult

Question 16

Which of the following is a plausible explanation for the rapid diversification of animal phyla during the Cambrian explosion?

Accepted Answer

Rising oxygen and calcium levels, presence of shallow seas, and changes in predator-prey relationships

Question 17

Which of the following is NOT a specialized sensory ability found in animals?

Accepted Answer

Ability to sense ultraviolet radiation for photosynthesis

Question 18

Which of the following statements about mass extinction events (MSEs) is supported by the study materials?

Accepted Answer

Previous MSEs were likely due to drastic climate change caused by asteroids and/or tectonic events

Question 19

Which of the following is a correct match between a non-bilaterian animal phylum and its key characteristic?

Accepted Answer

Ctenophora: sticky cells called colloblasts for trapping prey

Question 20

Which equation best represents the relationship between the number of described animal species ($D$), the total estimated number of animal species ($T$), and the percentage described ($P$)?

Accepted Answer

$P = \frac{D}{T} 	imes 100$

Chapter 30: An Introduction to Animals – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards