Question 1

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

Accepted Answer

The Ediacaran fauna is known for its lack of hard body parts, with a few exceptions such as the trace fossils left behind by its members. Therefore, finding fossils of organisms with hard body parts would be unexpected and surprising.

Question 2

The flagella of choanocyte cells in a sponge are most similar in basic function to

Accepted Answer

The flagella of choanocyte cells in sponges create water currents to move water through the sponge, similar to how cilia in the trachea move mucus and particles out of the lungs. Both involve moving substances along a surface rather than propelling the cell itself.

Question 3

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

Accepted Answer

Gene duplication is the most helpful genetic process in accounting for the Cambrian explosion, as it allowed for the creation of new genes and proteins that could drive evolutionary innovation and the diversification of body plans. This process could have led to the rapid evolution of new features and adaptations during the explosion. Binary fission and mitosis are both cell division processes that are not directly related to the evolution of new genes, while meiosis is a form of cell division that creates haploid cells for sexual reproduction, but does not directly create new genes.

Question 4

-Using the figure above,what is the minimum age of the common ancestor of Sponges and Cnidarians?

Accepted Answer

The minimum age of the common ancestor of Sponges and Cnidarians is 695 million years, as indicated by the figure.

Question 5

-Use the figure to identify the most recent common ancestor of Chordates and Arthropods.How many other taxonomic groups shown in this phylogenetic tree share that same common ancestor?

Accepted Answer

The answer of 
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Question 6

Which of the following is true of members of the phylum Cnidaria?

Accepted Answer

Members of the phylum Cnidaria, such as jellyfish and sea anemones, coordinate movements through a noncentralized nerve set called a nerve net. They lack a centralized brain, but their nerve net allows for basic responses to stimuli. They do have muscle-like cells called cnidocytes, but they do not have true muscle tissue, so they are not capable of complex locomotion. While some members of the phylum Cnidaria are filter feeders, many are also carnivorous and capture prey with their stinging cells. They have a simple digestive system with a single opening, so they do not have a complete alimentary canal.

Question 7

Sponges are most accurately described as

Accepted Answer

Sponges are filter feeders, meaning they filter small particles from the water to eat. They are not predators and do not produce their own food through chemosynthesis or photosynthesis. While some sponges can live in freshwater, they are more commonly found in marine habitats.

Question 8

-Use the figure to identify the most recent common ancestor of Echinoderms and Chordates.How many other taxonomic groups shown in this phylogenetic tree share that same common ancestor?

Accepted Answer

The answer of 
-Use the figure to identify the most...

Question 9

In terms of food capture,which sponge cell is most similar to the cnidocyte of a cnidarian?

Accepted Answer

The choanocyte (also called a collar cell) is most similar to the cnidocyte of a cnidarian in terms of food capture. Both cells have a protruding structure with a flagellum surrounded by a collar of microvilli that helps to capture food particles.

Question 10

Which of the following functions as both a mouth and an anus in members of the phylum Cnidaria?

Accepted Answer

Members of the phylum Cnidaria, such as jellyfish and corals, have a gastrovascular cavity that serves as both a mouth and an anus. This cavity allows for the intake of food and the expulsion of waste.

Question 11

The members of which clade in the phylum Cnidaria exist only as polyps?

Accepted Answer

Anthozoa is the only clade in the phylum Cnidaria that exists only as polyps. They include sea anemones and corals, which do not have a medusa stage in their life cycle. Hydrozoa and Scyphozoa have both polyp and medusa stages in their life cycles. Arthropoda is not related to the phylum Cnidaria.

Question 12

According to the evidence collected so far,the animal kingdom is

Accepted Answer

The evidence collected so far supports the monophyletic nature of the animal kingdom, which means that all animals share a common ancestor and all descendants of that ancestor are included in the animal kingdom. This is based on molecular, fossil, and anatomical evidence.

Question 13

The most ancient branch point in animal phylogeny is that between having

Accepted Answer

The most ancient branch point in animal phylogeny is believed to be between animals with true tissues (Eumetazoa) and those without (Porifera, Ctenophora, and Placozoa). This is supported by molecular and morphological data. The other options (A, B, and D) all represent more recent evolutionary innovations that occurred after the divergence of animals with true tissues.

Question 14

If the current molecular evidence regarding animal origins is well substantiated in the future,then what will be true of any contrary evidence regarding the origin of animals derived from the fossil record?

Accepted Answer

Molecular evidence provides a more comprehensive view of evolutionary relationships and can fill in gaps where the fossil record is incomplete or ambiguous. Therefore, if the current molecular evidence regarding animal origins is well substantiated in the future, any contrary evidence derived from the fossil record will likely be interpreted as incomplete rather than dismissed entirely.

Question 15

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

Accepted Answer

The Cambrian explosion was a rapid diversification and proliferation of life forms during the early Cambrian period, believed to be caused by an adaptive radiation, where new species evolved to fill ecological niches in response to changing environmental conditions. This sudden increase in diversity is different from evolutionary stasis, mass extinction or a large meteor impact.

Question 16

Which of the following is unique to animals?

Accepted Answer

Nervous conduction and muscular movement are unique to animals and allow for complex movement and behavior not seen in other organisms. A) Cells that have mitochondria are found in all eukaryotic organisms, including plants and fungi. B) Chitin is found in the cell walls of fungi and the exoskeleton of insects and crustaceans. D) Heterotrophy is the ability to obtain nutrients from other organisms, and is seen in both animals and some fungi. E) Flagellated gametes are found in some protists, including some algae and protozoans.

Question 17

Both animals and fungi are heterotrophic.The fact below that distinguishes animal heterotrophy from fungal heterotrophy is that only animals derive their nutrition from

Accepted Answer

Animals obtain nutrition by ingesting food, while fungi absorb nutrients from their surroundings. Both animals and fungi can consume living or dead prey, and both use enzymes to digest their food.

Question 18

The last common ancestor of all animals was probably a(n)

Accepted Answer

The last common ancestor of all animals is believed to be a single-celled organism belonging to the kingdom Protista.

Question 19

-Use the figure to identify the most recent common ancestor (branch point)of Brachiopods and Echinoderms.How many other common ancestors (branch points)must be considered when comparing these taxa to Sponges?

Accepted Answer

The answer of 
-Use the figure to identify the most...

Question 20

Which statement is most consistent with the hypothesis that the Cambrian explosion was caused by the rise of predator-prey relationships?

Accepted Answer

The rise of predator-prey relationships during the Cambrian explosion is most directly linked to the increased incidence of hard body parts in the fossil record. This is because organisms developed hard body parts, such as shells and exoskeletons, as protective mechanisms against predation, marking a significant evolutionary response to the new predatory pressures of the time.

Quiz 27: The Rise of Animal Diversity

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

The flagella of choanocyte cells in a sponge are most similar in basic function to

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

-Using the figure above,what is the minimum age of the common ancestor of Sponges and Cnidarians?

-Use the figure to identify the most recent common ancestor of Chordates and Arthropods.How many other taxonomic groups shown in this phylogenetic tree share that same common ancestor?

Which of the following is true of members of the phylum Cnidaria?

Sponges are most accurately described as

-Use the figure to identify the most recent common ancestor of Echinoderms and Chordates.How many other taxonomic groups shown in this phylogenetic tree share that same common ancestor?

In terms of food capture,which sponge cell is most similar to the cnidocyte of a cnidarian?

Which of the following functions as both a mouth and an anus in members of the phylum Cnidaria?

The members of which clade in the phylum Cnidaria exist only as polyps?

According to the evidence collected so far,the animal kingdom is

The most ancient branch point in animal phylogeny is that between having

If the current molecular evidence regarding animal origins is well substantiated in the future,then what will be true of any contrary evidence regarding the origin of animals derived from the fossil record?

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

Which of the following is unique to animals?

Both animals and fungi are heterotrophic.The fact below that distinguishes animal heterotrophy from fungal heterotrophy is that only animals derive their nutrition from

The last common ancestor of all animals was probably a(n)

-Use the figure to identify the most recent common ancestor (branch point) of Brachiopods and Echinoderms.How many other common ancestors (branch points) must be considered when comparing these taxa to Sponges?

Which statement is most consistent with the hypothesis that the Cambrian explosion was caused by the rise of predator-prey relationships?