Question 1

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

Accepted Answer

The fact that choanoflagellates and collar cells of sponges resemble each other suggests that they share a common ancestor and are closely related. This supports the inference that choanoflagellates and sponges are sister groups, meaning they share a more recent common ancestor with each other than with any other group of organisms.

Question 2

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

Accepted Answer

D

Question 3

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?

Accepted Answer

Collagen genes are found in all animals and their primary structure is well-conserved, making them a reliable choice for constructing a molecular-based phylogeny of the animal kingdom. Genes involved in chitin synthesis may not be present in all animal groups, genes involved in directing segmentation development may not be conserved across all animal phyla, and genes involved in eye-lens synthesis may not be present in all animals or may have evolved independently in different groups.

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?

Accepted Answer

T. adhaerens is the only known animal without muscle and nerve cells. While other animals may lack certain cell types or have cilia, the lack of muscle and nerve cells is unique to T. adhaerens.

Question 5

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?

Accepted Answer

Changes in the homeobox genes that control early development can have a significant impact on the developmental pathway of an organism. In insects, changes in these genes have been linked to the evolution of different types of metamorphosis. Therefore, option B is the most direct factor involved in the evolution of these variations. Artificial selection (A) may lead to changes in developmental pathways, but it is not a natural process. Meiosis (C) is involved in sexual reproduction but not directly related to metamorphosis. The origin of a brain (D) may have contributed to the complexity of insect behavior, but it is not a direct factor in the evolution of metamorphosis.

Question 6

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

Accepted Answer

Choanoflagellates are actually protists and not animals, while sponges, corals, and jellyfish are all classified as animals.

Question 7

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

Accepted Answer

Nervous system signal conduction and muscular movement are unique to animals. The other options, chitin, heterotrophy, and flagellated gametes, can be found in other organisms such as fungi, plants, and protists.

Question 8

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

Accepted Answer

The last common ancestor of all animals was likely a flagellated protist because this group shares many morphological and molecular features with animals, such as the presence of collagen and similar cell signaling pathways. The other options (A, B, and C) are not as closely related to animals and lack these key similarities.

Question 9

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.

Accepted Answer

Metastasizing cancer cells need to detach from the primary tumor and move to distant sites in the body. This requires them to be less "sticky" to adjacent cells and the extracellular matrix. Mutations in cadherin proteins can lead to this reduced "stickiness" and facilitate the spread of cancer cells. Therefore, choice A is the most likely correct statement.

Question 10

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

Accepted Answer

The Cambrian explosion is marked by a burst of diversification among animal phyla, suggesting a rapid radiation of new forms in response to ecological opportunities. This is a classic example of adaptive radiation.

Question 11

Use the table to answer the following question.
\(\begin{array}{c}
\begin{array}{|l|}
\hline \
\text {Organism}\
\hline \
\
\
\text {A}\
\hline \
\
\
\
\text {B}\
\hline \
\
\
\text {C} \
\hline \
\
\
\text { D }\
\hline
\end{array}
\begin{array}{l|}
\hline \
\text {Appearance}\
\hline \ 
\text {Microscopic,}\
 \text {unicellular, with a}\
\text { flagellum}\
\hline\text { Shaped like a}\ 
\text { basketball, covered }\
\text { with purple}\
 \text { filaments,}\ 
\text { multicellular }\
\hline\text {Hard and branched. }\
\text {multicellular,}\
 \text {covered in a sticky }\
\text {coating}\
\hline\
\
\text {Multicellular with }\
\text {cell walls}\
\hline
\end{array}
\begin{array}{l|}
\hline \
\text {Habitat/Activity}\
\hline \
\
\text {Swims around in }\
\text {freshwater pools}\
\hline \
\
\
\text {Rolls slowly across }\
\text {grassy fields}\
\hline \
\
\text {Attached to rocky }\
\text {surfaces}\
\hline \
\
\

\text {Flies across fields}\
\hline
\end{array}
\begin{array}{l|}

\hline\text {Nutrient}\
\text {Acquisition}\
\hline\text {Envelops and}\
\text {consumes other}\
\text {microscopic}\
\text {organisms}\
\hline\
\text {Thrives with access}\
\text {to only freshwater}\
\text {and sunlight}\
\hline\
\text {Traps insects in}\
\text {sticky coating and}\
\text {dissolves them}\
\hline\text {Constructs nets to}\
\text {trap flying}\
\text {organisms, and}\
\text {sucks out internal}\
\text {fluids}\
\hline
\end{array}
\begin{array}{l|}
\hline \
\text {Reproduction}\
\hline\
\
\text {Mates with others; }\
\text {young bud off}\
\hline\text {Mates with others;}\
\text { young emerge from }\
\text {hardened spherical }\
\text {structures}\
\hline\text {No mating, releases }\
\text {winged young that }\
\text {fly off and affix to}\
 \text {bare rocks}\
\hline\
\
 \text {Mates with others, }\
 \text {and disperses }\
 \text {young ballistically}\
\hline
\end{array}
\end{array}\)

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?

Accepted Answer

Organism C is multicellular with cell walls, which are made of cellulose and collagen.

Question 12

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

Accepted Answer

The Ediacaran fauna is characterized by soft-bodied organisms without hard parts, so the discovery of fossils with hard parts would be unexpected. All of the other options are features that have been found among the Ediacaran fauna.

Question 13

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 ________.

Accepted Answer

Sensing the environment, feeding, and moving are fundamental aspects of animal life that have evolved in diverse ways across species and have contributed to the vast array of animal diversity we see today. Reproduction and embryonic development are also important factors in animal evolution, but they may not account for as much diversity as the ability to sense, feed, and move. Arranging cells into tissues is also an essential aspect of animal development, but may not be as significant in terms of overall evolutionary diversity.

Question 14

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

Accepted Answer

The answer of Arthropods invaded land about 100 million years...

Question 15

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 ________.

Accepted Answer

The answer of In individual insects of some species, whole...

Question 16

Use the table to answer the following question.
\(\begin{array}{c}
\begin{array}{|l|}
\hline \
\text {Organism}\
\hline \
\
\
\text {A}\
\hline \
\
\
\
\text {B}\
\hline \
\
\
\text {C} \
\hline \
\
\
\text { D }\
\hline
\end{array}
\begin{array}{l|}
\hline \
\text {Appearance}\
\hline \ 
\text {Microscopic,}\
 \text {unicellular, with a}\
\text { flagellum}\
\hline\text { Shaped like a}\ 
\text { basketball, covered }\
\text { with purple}\
 \text { filaments,}\ 
\text { multicellular }\
\hline\text {Hard and branched. }\
\text {multicellular,}\
 \text {covered in a sticky }\
\text {coating}\
\hline\
\
\text {Multicellular with }\
\text {cell walls}\
\hline
\end{array}
\begin{array}{l|}
\hline \
\text {Habitat/Activity}\
\hline \
\
\text {Swims around in }\
\text {freshwater pools}\
\hline \
\
\
\text {Rolls slowly across }\
\text {grassy fields}\
\hline \
\
\text {Attached to rocky }\
\text {surfaces}\
\hline \
\
\

\text {Flies across fields}\
\hline
\end{array}
\begin{array}{l|}

\hline\text {Nutrient}\
\text {Acquisition}\
\hline\text {Envelops and}\
\text {consumes other}\
\text {microscopic}\
\text {organisms}\
\hline\
\text {Thrives with access}\
\text {to only freshwater}\
\text {and sunlight}\
\hline\
\text {Traps insects in}\
\text {sticky coating and}\
\text {dissolves them}\
\hline\text {Constructs nets to}\
\text {trap flying}\
\text {organisms, and}\
\text {sucks out internal}\
\text {fluids}\
\hline
\end{array}
\begin{array}{l|}
\hline \
\text {Reproduction}\
\hline\
\
\text {Mates with others; }\
\text {young bud off}\
\hline\text {Mates with others;}\
\text { young emerge from }\
\text {hardened spherical }\
\text {structures}\
\hline\text {No mating, releases }\
\text {winged young that }\
\text {fly off and affix to}\
 \text {bare rocks}\
\hline\
\
 \text {Mates with others, }\
 \text {and disperses }\
 \text {young ballistically}\
\hline
\end{array}
\end{array}\)

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?

Accepted Answer

Organism B thrives with access to only freshwater and sunlight, indicating it likely performs photosynthesis.

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?

Accepted Answer

The rise of predator-prey relationships would have led to an increase in animals developing hard parts for protection or for use in capturing prey. Fossils of hard parts such as shells, exoskeletons, and teeth are abundant in the Cambrian period and support the idea that predators played a significant role in the Cambrian explosion.

Question 18

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

Accepted Answer

Animals ingest materials (food) and then digest it with enzymes. Fungi, on the other hand, absorb nutrients from dead or decaying organic matter. While some animals do prey on other animals, it is not a defining characteristic of animal heterotrophy. Likewise, while some animals consume living prey, this is not the primary mode of obtaining nutrition for most animals.

Question 19

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

Accepted Answer

Gene duplication allows for the evolution of new genes with novel functions, which may have played a role in the rapid diversification of life during the Cambrian explosion.

Question 20

Use the table to answer the following question.
\(\begin{array}{c}
\begin{array}{|l|}
\hline \
\text {Organism}\
\hline \
\
\
\text {A}\
\hline \
\
\
\
\text {B}\
\hline \
\
\
\text {C} \
\hline \
\
\
\text { D }\
\hline
\end{array}
\begin{array}{l|}
\hline \
\text {Appearance}\
\hline \ 
\text {Microscopic,}\
 \text {unicellular, with a}\
\text { flagellum}\
\hline\text { Shaped like a}\ 
\text { basketball, covered }\
\text { with purple}\
 \text { filaments,}\ 
\text { multicellular }\
\hline\text {Hard and branched. }\
\text {multicellular,}\
 \text {covered in a sticky }\
\text {coating}\
\hline\
\
\text {Multicellular with }\
\text {cell walls}\
\hline
\end{array}
\begin{array}{l|}
\hline \
\text {Habitat/Activity}\
\hline \
\
\text {Swims around in }\
\text {freshwater pools}\
\hline \
\
\
\text {Rolls slowly across }\
\text {grassy fields}\
\hline \
\
\text {Attached to rocky }\
\text {surfaces}\
\hline \
\
\

\text {Flies across fields}\
\hline
\end{array}
\begin{array}{l|}

\hline\text {Nutrient}\
\text {Acquisition}\
\hline\text {Envelops and}\
\text {consumes other}\
\text {microscopic}\
\text {organisms}\
\hline\
\text {Thrives with access}\
\text {to only freshwater}\
\text {and sunlight}\
\hline\
\text {Traps insects in}\
\text {sticky coating and}\
\text {dissolves them}\
\hline\text {Constructs nets to}\
\text {trap flying}\
\text {organisms, and}\
\text {sucks out internal}\
\text {fluids}\
\hline
\end{array}
\begin{array}{l|}
\hline \
\text {Reproduction}\
\hline\
\
\text {Mates with others; }\
\text {young bud off}\
\hline\text {Mates with others;}\
\text { young emerge from }\
\text {hardened spherical }\
\text {structures}\
\hline\text {No mating, releases }\
\text {winged young that }\
\text {fly off and affix to}\
 \text {bare rocks}\
\hline\
\
 \text {Mates with others, }\
 \text {and disperses }\
 \text {young ballistically}\
\hline
\end{array}
\end{array}\)

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?

Accepted Answer

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

Quiz 32: An Overview of Animal Diversity

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

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

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?

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

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

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

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.

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

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 ________.

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

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 ________.

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?

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

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