Question 1

What do animals ranging from corals to monkeys have in common?
A) a mouth and an anus
B) number of embryonic tissue layers
C) some type of body symmetry
D) presence of Hox genes

Accepted Answer

All animals, from corals to monkeys, have Hox genes, which are crucial for determining the body plan and the development of structures along the anterior-posterior axis.

Question 2

Arthropods invaded land about 100 million years before vertebrates. This fact most clearly implies that ________.
A) arthropods evolved before vertebrates did
B) extant terrestrial arthropods are better adapted to terrestrial life than are extant terrestrial vertebrates
C) vertebrates evolved from arthropods
D) arthropods have had more time to coevolve with land plants than have vertebrates

Accepted Answer

Arthropods invading land earlier means they have had more time to interact and coevolve with land plants compared to vertebrates.

Question 3

Which of the following is (are) unique to animals?
A) the structural carbohydrate, chitin
B) nervous system signal conduction and muscular movement
C) heterotrophy
D) flagellated gametes

Accepted Answer

Nervous system signal conduction and muscular movement are unique to animals and not found in other organisms. Chitin is also found in fungi and some insects, heterotrophy is found in many other organisms including plants, and flagellated gametes are found in some protists.

Question 4

Use the information to answer the question.
Trichoplax adhaerens is the only living species in the phylum Placozoa. Individuals are about 1 mm wide and only 27 µm high, are irregularly shaped, and consist of a total of about 2,000 cells, which are diploid (2n = 12). There are four types of cells, none of which are nerve or muscle cells, and none of which have cell walls. Individual animals move using cilia, and any "edge" can lead. T. adhaerens feeds on marine microbes, mostly unicellular green algae, by crawling atop the algae and trapping it between its ventral surface and the substrate. Enzymes are then secreted onto the algae, and the resulting nutrients are absorbed. T. adhaerens sperm cells have never been observed, nor have embryos past the 64-cell (blastula) stage.
Which of the following T. adhaerens traits is different from all other known animals?
A) T. adhaerens is multicellular.
B) T. adhaerens lacks muscle and nerve cells.
C) T. adhaerens has cilia.
D) T. adhaerens lacks cell walls.

Accepted Answer

While many animals may lack one or the other, T. adhaerens is unique in that it lacks both muscle and nerve cells.

Question 5

Which of the following genetic processes may be most helpful in accounting for the Cambrian explosion?
A) binary fission
B) random segregation
C) gene duplication
D) chromosomal condensation

Accepted Answer

Gene duplication would have allowed for new genes to arise, which could have led to the development of new structures and functions during the Cambrian explosion.

Question 6

Use the table to answer the following question.

As you are on the way to Tahiti for a vacation, your plane crash lands on a previously undiscovered island. You soon find that the island is teeming with unfamiliar organisms, and you, as a student of biology, decide to survey them (with the aid of the Insta-Lab Portable Laboratory you brought along in your suitcase). You select four organisms and observe them in detail, making the notations found in the figure.
In which of the organisms listed would you search for collagen?
A) organism A
B) organism B
C) organism C
D) organism D

Accepted Answer

The answer of Use the table to answer the following...

Question 7

Cadherin proteins help animal cells stick (adhere) to each other. Choose which statement about cadherin in cancer cells that are metastasizing (spreading) throughout a patient's body is most likely correct.
A) Cadherin proteins in metastasizing cancer cells are likely to have mutations that make them less "sticky."
B) Cadherin proteins in metastasizing cancer cells are likely to have mutations that make them more "sticky."
C) Mutations in cadherin proteins are unlikely to affect the metastasizing of cancer cells.
D) Mutations in cadherin proteins accumulate at a constant rate that can be measured by a molecular clock.

Accepted Answer

Cadherin proteins in metastasizing cancer cells are likely to have mutations that make them less "sticky." This decrease in adhesion could allow cancer cells to detach from the primary tumor and spread to other parts of the body.

Question 8

Evidence of which structure or characteristic would be most surprising to find among fossils of the Ediacaran fauna?
A) true tissues
B) hard parts
C) bilateral symmetry
D) embryos

Accepted Answer

Fossils of the Ediacaran fauna are known for their lack of hard parts, so finding fossils with hard parts would be surprising. The other options (true tissues, bilateral symmetry, and embryos) are all characteristics that have been found in some Ediacaran fossils.

Question 9

Use the table to answer the following question.

As you are on the way to Tahiti for a vacation, your plane crash lands on a previously undiscovered island. You soon find that the island is teeming with unfamiliar organisms, and you, as a student of biology, decide to survey them (with the aid of the Insta-Lab Portable Laboratory you brought along in your suitcase). You select four organisms and observe them in detail, making the notations found in the figure.
Which organism would you classify as an animal?
A) organism A
B) organism B
C) organism C
D) organism D

Accepted Answer

The answer of Use the table to answer the following...

Question 10

The larvae of some insects are merely small versions of the adult, whereas the larvae of other insects look completely different from adults, eat different foods, and may live in different habitats. Which of the following is most directly involved in the evolution of these variations in metamorphosis?
A) artificial selection of sexually immature forms of insects
B) changes in the homeobox genes controlling early development
C) the evolution of meiosis
D) the origin of a brain

Accepted Answer

Changes in homeobox genes controlling early development are most directly involved in the evolution of variations in metamorphosis because these genes regulate the development of body structures and organs. Changes in these genes can result in different larval forms and adaptations to different habitats and diets. Artificial selection, the evolution of meiosis, and the origin of a brain are not directly related to the evolution of these variations in metamorphosis.

Question 11

The evolution of animal species has been prolific (current estimates of species numbers reach into the tens of millions). Much of this diversity is a result of the evolution of novel ways to ________.
A) reproduce
B) arrange cells into tissues
C) sense, feed, and move
D) form an embryo and establish a basic body plan

Accepted Answer

Sensing, feeding, and movement are all key aspects of an animal's survival and have contributed significantly to the diversification of animal species. Reproduction and formation of a basic body plan are also important factors in evolution, but do not account for as much of the diversity seen in the animal kingdom as sensing, feeding, and movement. Cell arrangement into tissues is an important step in the development of complex organisms but is not as directly related to animal diversity as the other options.

Question 12

In individual insects of some species, whole chromosomes that carry larval genes are eliminated from the genomes of somatic cells at the time of metamorphosis. A consequence of this occurrence is that ________.
A) we could not clone a larva from the somatic cells of such an adult insect
B) such species must reproduce only asexually
C) the descendants of these adults do not include a larval stage
D) metamorphosis can no longer occur among the descendants of such adults

Accepted Answer

The elimination of chromosomes carrying larval genes from somatic cells means that these cells lack the genetic information necessary to produce a larva, making it impossible to clone a larva from them.

Question 13

Both animals and fungi are heterotrophic. What distinguishes animal heterotrophy from fungal heterotrophy is that most animals derive their nutrition by ________.
A) preying on animals
B) ingesting materials
C) consuming living, rather than dead, prey
D) using enzymes to digest their food

Accepted Answer

Most animals ingest their food, meaning they take in solid or liquid food through their mouth, chew and digest it in their digestive system. Fungi, on the other hand, absorb nutrients through their cell walls from dead or organic matter in their environment.

Question 14

Whatever its ultimate cause(s), the Cambrian explosion is a prime example of ________.
A) mass extinction
B) evolutionary stasis
C) adaptive radiation
D) a large meteor impact

Accepted Answer

The Cambrian explosion refers to a rapid diversification of life forms during the Cambrian period. This diversification appears to have been an adaptive radiation, in which new species evolved to fill a variety of ecological niches.

Question 15

Which of the following would you classify as something other than an animal?
A) sponge
B) coral
C) jellyfish
D) choanoflagellate

Accepted Answer

Choanoflagellates are single-celled organisms that are considered the closest living relatives of animals but are not classified as animals themselves.

Question 16

A researcher is trying to construct a molecular-based phylogeny of the entire animal kingdom. Assuming that none of the following genes are absolutely conserved, which of the following would be the best choice on which to base the phylogeny?
A) genes involved in chitin synthesis
B) collagen genes
C) genes involved in directing segmentation development
D) genes involved in eye-lens synthesis

Accepted Answer

Collagen genes are found in all animals and are involved in the formation of key structures such as connective tissues and the extracellular matrix. Thus, these genes are more likely to accurately reflect the evolutionary history of the entire animal kingdom compared to genes involved in more specialized processes such as chitin synthesis or eye-lens synthesis.

Question 17

One hypothesis suggests that the Cambrian explosion was caused by the rise of predator-prey relationships. This hypothesis is best supported by an increased incidence of which of the following fossil traces?
A) worm burrows
B) larger animals
C) organic material
D) hard parts

Accepted Answer

The rise of predator-prey relationships is believed to have driven the evolution of hard parts, such as shells, spines, and exoskeletons, for protection and defense. Therefore, an increased incidence of fossilized hard parts would support this particular hypothesis.

Question 18

The last common ancestor of all animals was probably a ________.
A) unicellular chytrid
B) multicellular algae
C) multicellular fungus
D) flagellated protist

Accepted Answer

The last common ancestor of all animals is believed to be a flagellated protist, as molecular and genetic evidence suggest that animals are closely related to choanoflagellates, a group of single-celled eukaryotes with flagella.

Question 19

Use the table to answer the following question.

As you are on the way to Tahiti for a vacation, your plane crash lands on a previously undiscovered island. You soon find that the island is teeming with unfamiliar organisms, and you, as a student of biology, decide to survey them (with the aid of the Insta-Lab Portable Laboratory you brought along in your suitcase). You select four organisms and observe them in detail, making the notations found in the figure.
In which of the organisms listed would you search for photosynthetic genes?
A) organism A
B) organism B
C) organism C
D) organism D

Accepted Answer

The answer of Use the table to answer the following...

Question 20

The fact that choanoflagellates and collar cells of sponges resemble each other supports the inference that ________.
A) choanoflagellates are animals
B) choanoflagellates are more closely related to sponges than they are to protists
C) choanoflagellates and sponges are sister groups
D) choanoflagellates and sponges evolved similar cell structures through convergent evolution

Accepted Answer

The similarity between choanoflagellates and collar cells of sponges suggests that they share a common ancestor and are therefore closely related. The resemblance supports the idea that choanoflagellates and sponges are sister groups.

Quiz 32: An Overview of Animal Diversity

What do animals ranging from corals to monkeys have in common?

Arthropods invaded land about 100 million years before vertebrates. This fact most clearly implies that ________.

Which of the following is (are) unique to animals?

Which of the following genetic processes may be most helpful in accounting for the Cambrian explosion?

Cadherin proteins help animal cells stick (adhere) to each other. Choose which statement about cadherin in cancer cells that are metastasizing (spreading) throughout a patient's body is most likely correct.

Evidence of which structure or characteristic would be most surprising to find among fossils of the Ediacaran fauna?

The evolution of animal species has been prolific (current estimates of species numbers reach into the tens of millions) . Much of this diversity is a result of the evolution of novel ways to ________.

In individual insects of some species, whole chromosomes that carry larval genes are eliminated from the genomes of somatic cells at the time of metamorphosis. A consequence of this occurrence is that ________.

Both animals and fungi are heterotrophic. What distinguishes animal heterotrophy from fungal heterotrophy is that most animals derive their nutrition by ________.

Whatever its ultimate cause(s) , the Cambrian explosion is a prime example of ________.

Which of the following would you classify as something other than an animal?

A researcher is trying to construct a molecular-based phylogeny of the entire animal kingdom. Assuming that none of the following genes are absolutely conserved, which of the following would be the best choice on which to base the phylogeny?

One hypothesis suggests that the Cambrian explosion was caused by the rise of predator-prey relationships. This hypothesis is best supported by an increased incidence of which of the following fossil traces?

The last common ancestor of all animals was probably a ________.

The fact that choanoflagellates and collar cells of sponges resemble each other supports the inference that ________.