Chapter 11: Animal Diversification

Terrestrial vertebrates are descendants of lobe-finned fishes that lived during the Devonian period, approximately:

400 million years ago. The Devonian period took place about 400 million years ago. Terrestrial vertebrates' ancestors, the lobe-finned fishes, lived during this time.

Which of the following about insects is FALSE?

All insects have three life stages: larva, pupa, and adult. ****Not all insects go through three distinct life stages; about 83% of insect species do. Some insects, like grasshoppers, only have two stages, nymph and adult, which is known as incomplete metamorphosis***

Which of the following best explains why fins and jaws evolved in a parallel manner?

Fins and jaws work together: Fins get you to the organism you are going to eat, and jaws capture and kill it. ***The two work in tandem: fins provide controlled movement through water, and jaws allow for seizing and chewing prey***

Which of the following is not a crustacean?

Portuguese man-o'-war Correct! Portuguese man-o'-war are cnidarians.

Which of the following is true of reptiles but not amphibians? Reptiles were the earliest animal group to evolve lungs. Reptiles can't live in water, while all amphibians live in water throughout their lives. Reptiles are endotherms, while amphibians are ectotherms. Reptiles are less closely related to whales, while amphibians are more closely related to whales. Reptiles have amniotic eggs, whereas amphibians do not.

Reptiles have amniotic eggs, whereas amphibians do not. As a result, amphibians must lay their eggs in water, while reptiles lay their eggs on land.

Sea stars, a type of echinoderm, are seemingly harmless organisms. Which of the following, if any, is a defense/predation mechanism of the sea star? The tube feet create a combined force to pull apart shells of a clam or mussel. The stomach can be pushed out through the mouth into a slightly opened clam shell, secreting digestive enzymes. Sharp, tooth-like surfaces can scrape algae loose from rocks. Streams of mucus can be used to capture food. The first two choices are correct.

The first two choices are correct. ***Although they look like defenseless organisms, they hunt bivalves, holding onto to them, spreading their shells apart, inserting their stomachs inside, and digesting them. They are hardly defenseless!***

Which of the following is unique about vertebrates in terms of the phylum Chordata?

The notochord is not present throughout life; rather, it is only found in early embryos and is replaced by the vertebral column (backbone). Vertebrates uniquely have a backbone that forms around the notochord. Likewise, vertebrates have a head at the anterior end of the organism.

What is the key difference between protostomes and deuterostomes?

The protostome gut develops from front to back, so the first opening is the mouth. The deuterostome gut develops back to front, and the second opening becomes the mouth. ***The way in which their gut develops is the difference between the two***

The most primitive group of animals that had lungs were the: reptiles. ray-finned fish. tunicates. amphibians. birds.

amphibians. They have primitive lungs and were important to the transition to land.

The notochord that characterizes all chordates at some stage in their life cycle provides all of the following functions EXCEPT:

bony protection for the nerve cord. In complex chordates the notochord is only present in the early embryo. It is then replaced by the backbone.

The swim bladder in ray-finned fishes is believed to be homologous to the _______ of terrestrial vertebrates.

lungs The swim bladder of ray-finned fish is a gas-filled organ that keeps the fish from sinking. It is believed to be homologous to the lungs of land-dwelling vertebrates, as both evolved from simple air sacs connected to the gut.

Which of the following is NOT an important feature in distinguishing animals from each other? body symmetry presence and cellular arrangement of tissues method of locomotion (movement) growth of skeletal elements development of the gut

method of locomotion (movement) This is not a common feature used to separate animal groups.

Each group of animals below is paired with a type of body symmetry. Which of these pairings is incorrect? cnidaria; radial symmetry sponge; asymmetry roundworm; radial symmetry fish; bilateral symmetry mammal; bilateral symmetry

oundworm; radial symmetry This is an incorrect pairing. Roundworms have bilateral symmetry—meaning they have left and right sides that essentially are mirror images, and not radial symmetry—a body structured like a pie.

The molluscan mantle is used primarily for:

producing the shell. The mantle is the tissue that produces calcium carbonate to form the shell, which protects mollusks' soft bodies.

Which of the following correctly pairs a stage of arthropod metamorphosis with its most significant change at that stage?

pupa: body structures of the larva are broken down and reassembled This is the actual defining stage of metamorphosis, when the larva encloses itself in a case, body structures are broken down, and new structures are assembled into adult form.

All groups of animals have nervous systems EXCEPT:

sponges. sponges lack a nervous system. In fact, sponges have no tissues or organ systems.

Which of the following is NOT an arthropod? squid louse shrimp flea horseshoe crab

squid Like other cephalopods, squids have tentacles used for movement and capturing prey.

Which of the following is NOT one of the major evolutionary adaptations that occurred as animals moved from water to land?

swim bladder A swim bladder is homologous to the lungs of land-dwelling vertebrates and is not one of the major evolutionary adaptations that occurred as animals moved from water to land.