Question 1

You discover an organism that has scaly skin and is aquatic but returns to the land to reproduce.What else would you expect to find in this organism?

Accepted Answer

Since the organism returns to land to reproduce, it must have some adaptations for terrestrial reproduction. One such adaptation is the amniotic egg, which allows for reproduction on land in a protected environment. The other options (asexual reproduction, water vascular system, radial symmetry) do not necessarily relate to the organism's transition to land for reproduction.

Question 2

Which animals have a cylindrical body that is tapered at both ends?

Accepted Answer

D

Question 3

A characteristic of arthropods that has allowed for their great success is the presence of ________.

Accepted Answer

The presence of specialized segments, such as the head, thorax, and abdomen, has allowed arthropods to adapt to a wide range of environments and perform various functions, such as locomotion, feeding, and reproduction. This has contributed to their great success, as they are the most diverse group of animals on Earth, with over a million described species.

Question 4

What name is given to the food-trapping cells of sponges?

Accepted Answer

The food-trapping cells of sponges are called choanocytes, which help to trap and digest food particles. Cnidocytes are found in cnidarians such as jellyfish and function in defense or capturing prey. Amoebocytes are cells that aid in transport and storage of nutrients in sponges, and skeletal fibers provide structural support in sponges.

Question 5

What characteristic is unique to echinoderms?

Accepted Answer

Echinoderms possess a water vascular system, which is a unique characteristic not found in other animal phyla. This system includes a network of fluid-filled canals and specialized tube feet that help echinoderms with locomotion, feeding and respiration.

Question 6

Which of these exhibits radial symmetry?

Accepted Answer

A snowflake has radial symmetry because its branches and crystals extend outwards in a circular pattern from a central point. The other options (butterfly, spoon, and shoe box) do not have radial symmetry as they have bilateral symmetry (symmetrical along a single plane).

Question 7

The arthropod skeleton is composed of ________.

Accepted Answer

The arthropod skeleton is made of chitin, a complex polysaccharide that provides both strength and flexibility. It is not made of cellulose, peptidoglycan, or glycogen.

Question 8

There are more species of ________ than of any other type of animal.

Accepted Answer

Arthropods include insects, crustaceans, arachnids, and other groups, and they make up over 80% of all known animal species on Earth. Nematodes come in second place with around 14,000 known species, while molluscs and chordates have around 100,000 and 65,000 known species, respectively.

Question 9

The mobile stage of the cnidarian life cycle is the ________ stage.

Accepted Answer

The medusa stage is the mobile stage of the cnidarian life cycle. The polyp stage is typically sessile, meaning it remains attached to a substrate, and the other options (bilateral and tadpole) are not relevant stages in the cnidarian life cycle.

Question 10

You are given the task of confirming the categorization of a newly discovered animal that has been tagged as a species of annelid.What evidence would convince you that it is indeed an annelid and not a roundworm or flatworm?

Accepted Answer

Body segmentation is a defining characteristic of annelids, meaning that they have repeated body segments with corresponding sets of organs and appendages. This feature is not present in flatworms or roundworms. Therefore, observing body segmentation in the newly discovered animal would strongly suggest that it is an annelid. The other choices (incomplete digestive tract, highly branched gastrovascular cavity, and parasitic feeding habits) are not exclusive to annelids and can be found in other animal groups as well.

Question 11

A(n)________ is an example of a mollusc that does not have a shell.

Accepted Answer

Octopus is a mollusc that does not have a shell. Snails have shells, oysters have shells, and spiders are not molluscs.

Question 12

Humans are chordates.Which animal group is most closely related to chordates?

Accepted Answer

Echinoderms are the most closely related animal group to chordates, as both groups have a common ancestor in the deuterostomes. Both chordates and echinoderms share similar early embryonic development, including the formation of a dorsal nerve cord and notochord. Molluscs, annelids, and arthropods are all members of the protostome group and are not as closely related to chordates as echinoderms are.

Question 13

________ are the most diverse group of arthropods.

Accepted Answer

Insects are the most diverse group of arthropods, with over one million described species. They are found in almost every terrestrial and aquatic habitat and play important roles in ecosystems as pollinators, decomposers, and prey for other organisms. While the other choices (millipedes, arachnids, and crustaceans) are also arthropods, their total number of described species is much lower than that of insects.

Question 14

How do sponges differ from all other animals?

Accepted Answer

Sponges are the only animals that lack true tissues. They consist of loosely organized cells that function independently.

Question 15

Which of these is a defining characteristic of animals that distinguishes them from other eukaryotes?

Accepted Answer

Animals are distinguished from other eukaryotes by their mode of nutrition; they ingest food, unlike plants that use photosynthesis or fungi that absorb nutrients.

Question 16

The common ancestor of all animals is likely to have been a ________.

Accepted Answer

The common ancestor of all animals is believed to be a colonial, flagellated protist, similar to modern choanoflagellates, which are considered the closest living relatives of animals.

Question 17

________ are characterized by stinging cells used for defense and for capturing prey.

Accepted Answer

Cnidarians, such as jellyfish and corals, are the only group of animals that possess stinging cells called nematocysts. These cells can be used for both defense and capturing prey. Annelids (segmented worms) and roundworms do not have stinging cells, while sponges do have some defensive cells, but they are not specialized for stinging.

Question 18

J)R.R.Tolkien is a famous author who wrote,among others,several books about the adventures of a community of a humanoid (meaning resembling a human)race.The individuals of this race are described by Tolkien as being "…between 2 and 4 feet (0.61-1.22 m)tall,the average height being 3 feet 6 inches (1.07 m)… a fairly human figure." This general description characterizes the humanoids mostly closely resembling ________.

Accepted Answer

The description given by Tolkien closely resembles Homo floresiensis, which were a small-bodied hominin species that lived in Indonesia around 50,000 years ago. They were between 2 and 4 feet tall, with an average height of around 3 feet 6 inches, and had a body structure that was similar to humans. The other options, Homo sapiens, mandrills, and lemurs, do not match the description given by Tolkien.

Question 19

You encounter an insect with small eyes,long sensory antennae,and a long mouthpart shaped like a sword.What can you conclude about the environment in which it lives?

Accepted Answer

The insect's small eyes suggest it doesn't rely heavily on vision, indicating a dark environment. Long sensory antennae and a sword-shaped mouthpart suggest adaptation to navigating and feeding in a plant-rich environment.

Question 20

Nearly all ________ are aquatic.

Accepted Answer

Crustaceans are a type of arthropod that include species like crabs, lobsters, and shrimp. Nearly all crustaceans are aquatic, and can be found in a variety of aquatic habitats including oceans, freshwater lakes and rivers, and even underground caves. Arachnids, flatworms, and roundworms are all non-aquatic.

Quiz 17: The Evolution of Animals