Question 1

-Which part of this figure shows the thorax segment of the lobster?

Accepted Answer

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-Which part of this figure shows...

Question 2

Caddisflies are insects that lay their eggs on the bottom of streams. The eggs mature into larvae, and eventually the larvae pupate, move to the surface of the stream, shed their pupal membranes, and emerge as winged adults. Caddisflies demonstrate

Accepted Answer

Caddisflies go through complete metamorphosis as they have distinct larval, pupal, and adult stages.

Question 3

-Which group of animals is the most diverse?

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-Which group of animals is the...

Question 4

Suppose you use a dissecting microscope to observe organisms that have colonized discs of densely packed, fibrous wood (Masonite plates) that have been submerged in 6 inches of lake water for 8 weeks. You see insect cases (protective shelters), insect larvae, and newly emerged insects with wings. You determine that you are looking at an insect species

Accepted Answer

The presence of insect cases, larvae, and newly emerged insects with wings suggest that the insects are undergoing complete metamorphosis, which includes an egg, larval, pupal, and adult stage. Insects that undergo incomplete metamorphosis do not have a distinct pupal stage and usually have nymphs that resemble smaller versions of the adult. The body plan of radial symmetry pertains to organisms like jellyfish and starfish, and not insects. Incomplete digestive tracts refer to organisms that have only one opening for both ingestion and excretion, which is not specific to insects.

Question 5

For the following questions consider these characteristics:
I. radial symmetry
II. bilateral symmetry
III. true tissues
IV. complete digestive tract
-One of the most venomous organisms on earth is an Australian marine invertebrate that kills its prey using cnidocytes. These animals would be expected to have

Accepted Answer

The Australian marine invertebrate described belongs to the phylum Cnidaria, which is characterized by radial symmetry and true tissues. Therefore, it has characteristics I and III. It is not mentioned whether the organism has a complete digestive tract, so this characteristic cannot be assumed. Bilateral symmetry is not characteristic of cnidarians.

Question 6

For the following questions consider these characteristics:
I. radial symmetry
II. bilateral symmetry
III. true tissues
IV. complete digestive tract
-A scientist found thousands of small worms thrashing about in a very small amount of soil and determined that the thrashing motion was due to having only longitudinal muscles. These worms are likely to have

Accepted Answer

The worms described are likely nematodes, which have bilateral symmetry (II), true tissues (III), and a complete digestive tract (IV).

Question 7

For the following questions consider these characteristics:
I. radial symmetry
II. bilateral symmetry
III. true tissues
IV. complete digestive tract
-Parasitic sheep liver flukes would be expected to have

Accepted Answer

Parasitic sheep liver flukes exhibit bilateral symmetry and possess true tissues, but they do not have a complete digestive tract, as their digestive system ends in a blind sac rather than forming a separate exit.

Question 8

Corals belong to phylum Cnidaria. The reefs themselves are made up of millions of polyps, each of which secretes a calcium carbonate skeleton that becomes part of the reef structure. Corals, which are attached to the reef as adults, have free-swimming larvae that develop into new polyps.
Corals are actually colorless. The brilliant colors that are visible on the reef come from the zooxanthellae (microscopic algae) that live within their body tissues. The zooxanthellae and corals have a symbiotic relationship in which corals provide carbon dioxide and mineral nutrients (released as wastes from coral digestion) to the zooxanthellae. The zooxanthellae perform photosynthesis. Photosynthesis produces nutrients (in the form of sugars) for the coral and also releases oxygen. This relationship supplements energy from predation and allows corals to survive in clear tropical water, even though these areas have very low nutrient levels.
-Corals supplement the energy they receive from the zooxanthellae by capturing prey using their

Accepted Answer

Corals capture prey using their cnidocytes, which are specialized cells that contain nematocysts (stinging cells) that can capture small fish and plankton.

Question 9

The graph below is of an index of diversity of arthropods in three different plots of a cornfield. In one of the three plots an insecticide was sprayed. Answer the questions below about this situation.
  Arthropod diversity in three cornfield plots.
-When and where does it appear that the insecticide was applied?

Accepted Answer

The diversity index in Plot 3 significantly drops in July compared to Plots 1 and 2, indicating that the insecticide was likely applied in July in Plot 3. There is no significant drop in diversity in Plots 1 or 2 that can indicate the application of insecticide.

Question 10

-Starfish do not appear to have bilateral symmetry and yet the diagram indicates they are bilaterians. What other characteristics do they have that would confirm that classification?

Accepted Answer

Bilaterians are animals with bilateral symmetry - meaning their left and right sides are mirror images of each other. While adult starfish may not appear to have this symmetry, their larvae do have bilateral symmetry. Additionally, starfish have an anus that forms from the first opening in the embryo, which is a characteristic of bilaterians. Therefore, choice B is the best answer as it covers both of these characteristics.

Question 11

Corals belong to phylum Cnidaria. The reefs themselves are made up of millions of polyps, each of which secretes a calcium carbonate skeleton that becomes part of the reef structure. Corals, which are attached to the reef as adults, have free-swimming larvae that develop into new polyps.
Corals are actually colorless. The brilliant colors that are visible on the reef come from the zooxanthellae (microscopic algae) that live within their body tissues. The zooxanthellae and corals have a symbiotic relationship in which corals provide carbon dioxide and mineral nutrients (released as wastes from coral digestion) to the zooxanthellae. The zooxanthellae perform photosynthesis. Photosynthesis produces nutrients (in the form of sugars) for the coral and also releases oxygen. This relationship supplements energy from predation and allows corals to survive in clear tropical water, even though these areas have very low nutrient levels.
-What advantage do free-swimming larvae confer on reef-building corals?

Accepted Answer

Free-swimming larvae allow reef-building corals to expand their populations into new habitats by settling in new areas and developing into new polyps to build new reefs.

Question 12

-Which part of this figure shows the tube feet of the starfish?

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-Which part of this figure shows...

Question 13

Many sponges, cnidarians, and echinoderms have few if any external characteristics distinguishing males from females. This seemingly odd structural characteristic is most likely associated with which of these functions?

Accepted Answer

The answer of Many sponges, cnidarians, and echinoderms have few...

Question 14

Which of these molluscs commonly have a coiled shell?

Accepted Answer

Gastropods, such as snails and slugs, commonly have coiled shells. Bivalves, such as clams and oysters, have two connected shells that are not coiled. Cephalopods, such as squid and octopuses, have a more complex body structure and do not have a shell, or have a reduced internal shell.

Question 15

The graph below is of an index of diversity of arthropods in three different plots of a cornfield. In one of the three plots an insecticide was sprayed. Answer the questions below about this situation.
  Arthropod diversity in three cornfield plots.
-The fact that the lines generally rise from left to right indicates

Accepted Answer

The lines rise from left to right, implying that species diversity generally increased over time.

Question 16

The graph below is of an index of diversity of arthropods in three different plots of a cornfield. In one of the three plots an insecticide was sprayed. Answer the questions below about this situation.
  Arthropod diversity in three cornfield plots.
-Which of the following conclusions is supported by the data shown in the graph?

Accepted Answer

The graph shows that the index of diversity for all three plots combined was highest in July. Therefore, option C is correct. Option A is incorrect because the graph only shows changes in the number of individuals, not species. Option B is incorrect because the graph shows that there were more arthropods in June than in July, and September had the lowest number of arthropods overall. Option D is incorrect because while Plot 2 did have the highest index of diversity in August, the question asks about overall species diversity, not just one month.

Question 17

Which of these molluscs sometimes do not have an exterior shell?

Accepted Answer

Gastropods can have a shell or no shell, and cephalopods, such as squids and octopuses, also do not have an exterior shell. Bivalves always have a shell. Therefore, the correct choice is D, gastropods and cephalopods.

Question 18

-The most obvious feature that this animal shares with annelids is

Accepted Answer

The animal in the figure exhibits segmentation, which is a key characteristic of annelids. Segmentation involves the division of the body into a series of repeated segments, which is found in both annelids and the animal shown in the figure. The other choices (large claws, three major body regions, and several types of jointed appendages) are not exclusive to annelids and can be found in other animal groups.

Question 19

Which of these molluscs commonly have a hinged shell?

Accepted Answer

Bivalves are the molluscs that commonly have a hinged shell, which includes clams, oysters, and mussels. Gastropods have a single, univalve shell, while cephalopods have either no shell or a single internal shell.

Question 20

-Which phyla of animals are most closely related?

Accepted Answer

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-Which phyla of animals are most...

Quiz 18: The Evolution of Invertebrate Diversity