Bio 182 Chapter 33 & 34
Which of the following statements about vertebrates is true?
The development of an amniotic egg and internal fertilization allowed vertebrates to reproduce away from water. Reptiles and their descendants reproduce on land via an amniotic egg, which prevents the embryo from drying out.
Which characteristics define a chordate?
The presence of four specific morphological traits Chordates are defined by the presence of four morphological traits: a notochord, a dorsal nerve cord, pharyngeal gill slits, and a tail behind the anus.
Which of the following is characteristic of the phylum Platyhelminthes?
They are dorsoventrally flattened. This is why they are also called flatworms.
Which of the following is true of annelids
They perform gas exchange across their skin. Cutaneous respiration occurs across their skins. Polychaetes have lateral extensions, called parapodia, which provide even more surface area for cutaneous respiration.
In what respect do hominins differ from all other anthropoids
bipedal posture
Jaws evolved
by modification of the skeletal rods that previously supported the anterior pharyngeal gill slits According to a leading hypothesis, this marked a reduction in the number of pharyngeal gill slits and a change in the function of gills from feeding to respiration.
Jaws first occurred in which extant group of fishes
chondrichthyans
The earliest known mineralized structures in vertebrates are associated with
feeding
Nematodes and arthropods both
grow by shedding their exoskeleton
Healthy corals are brightly colored because they
host symbionts with colorful photosynthetic pigments
The presence of a lophophore in a newly discovered species would suggest that the species
is a suspension feeder
The common ancestor of all these chordate groups EXCEPT the _____ probably had paired appendages
lampreys Lampreys lack paired appendages.
Which extant chordates are postulated to be most like the earliest chordates in appearance
lancelets
Which of these is the only chordate group that has hair?
mammals Hair is one of the defining characteristics of mammals.
There are three major groups of mammals, categorized on the basis of their
method of reproduction Monotremes are egg-laying mammals, marsupials are pouched mammals, and eutherians are placental mammals.
You find what you believe is a new species of animal. Which of the following characteristics would enable you to argue that it is more closely related to a flatworm than it is to a roundworm?
It has no coelom.
Ectoprocts and brachiopods are collectively referred to as
LOPHOPHORATES The lophophore is a structure common to these two phyla that bear ciliated tentacles.
A marine biologist dredges up a small animal from the bottom of the ocean. It is uniformly segmented, with short, stiff appendages and soft, flexible skin. It has a complete digestive system and a closed circulatory system, plus multiple true coeloms. Based on this, you determine that the animal must be an
ANNELID The description matches the characteristics of annelids.
Which of the following statements about deuterostomes is false?
All deuterostomes exhibit radial symmetry in their bodies.
Which of the following are the only extant animals that descended directly from dinosaurs
BIRDS
The diagnostic feature of Chondrichthyes is
an endoskeleton of calcified cartilage The cartilaginous skeleton of sharks and their relatives is reinforced with calcium.
An elementary school science teacher decided to liven up the classroom with a saltwater aquarium. Knowing that saltwater aquaria can be quite a hassle, the teacher proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided to stock the tank with various marine invertebrates, including a polychaete, a siliceous sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial hydra, a few coral species, an ectoproct, a sea star, and several herbivorous gastropod varieties. Lastly, she added some vertebrates-a parrotfish and a clownfish. She arranged for daily feedings of copepods and feeder fish. The teacher and class were especially saddened when the colonial hydrozoan died. They had watched it carefully, and the unfortunate creature never even got to produce offspring by budding. Yet, everyone was elated when one of the students noticed a small colonial hydrozoan growing in a part of the tank far from the location of the original colony. The teacher was apparently unaware that these hydrozoans exhibit _____.
A MEDUSASTAGEpa
Which of the following is a characteristic of cnidarians?
GASTROVASCULAR CAVITY The gastrovascular cavity, characterized by a single opening, is the digestive compartment of cnidarians.
Ecdysozoans Protostomes are categorized into two clades: Lophotrochozoa and Ecdysozoa. Ecdysozoa includes about eight phyla, including the phyla Arthropoda and Nematoda. Arthropods and nematodes (roundworms) are among the most abundant of all animal groups. The simplified evolutionary tree below shows the relationship between arthropods, nematodes, and lophotrochozoans. (There are more ecdysozoan phyla than shown on this tree.) Nematodes and arthropods are the largest ecdysozoan phyla.
Both nematodes and arthropods possess an external covering, or cuticle Arthropods possess an open circulatory system. Some nematodes are parasitic on humans Arthropods are named for their jointed appendages. Both nematodes and arthropods must molt in order to increase in size The ecdysozoans include nematodes, arthropods, and other phyla that have tough external coats, or cuticles, that must be shed as they grow. This process of shedding, or molting, is called ecdysis. Nematodes, or roundworms, are unsegmented pseudocoelomate worms that lack a circulatory system. Although most nematodes are free-living, some well-known nematodes, such as hookworms and pinworms, are parasitic. Arthropods have a reduced coelom and an open circulatory system. Arthropods have segmented bodies that enable specialization of body structures such as appendages.
An elementary school science teacher decided to liven up the classroom with a saltwater aquarium. Knowing that saltwater aquaria can be quite a hassle, the teacher proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided to stock the tank with various marine invertebrates, including a polychaete, a siliceous sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial hydra, a few coral species, an ectoproct, a sea star, and several herbivorous gastropod varieties. Lastly, she added some vertebrates-a parrotfish and a clownfish. She arranged for daily feedings of copepods and feeder fish. If the teacher wanted to show the students what a lophophore is and how it works, the teacher would point out a feeding _____.
Ectoproct
Which structure is not an innovation that occurred during vertebrate diversification?
Exoskeleton Exoskeletons are present in groups other than the vertebrates, including some in the protostome lineage.
True or false? An organism that is radially symmetric has many well-developed head regions.
FALSE An organism that is radially symmetric does not have a well-developed head region.
Insect diversity Insects are the most diverse group of organisms, in terms of numbers of species, dominating terrestrial habitats. More than 30 orders of insects have been described, with the order Coleoptera being the largest. Classification is based on traits such as wings and mouthparts. All insects have a three-part body plan consisting of a head, thorax, and abdomen; three pairs of walking legs; and one or two pairs of wings. The chart below indicates defining characteristics for eight of the more than 30 orders of insects.
Insects and their relatives are the most species-rich group of living organisms. The diversity of characteristics such as wing shape, mouthparts, and reproductive tactics enable insects to live in most terrestrial and freshwater habitats. The evolutionary tree below shows the relationship between the phyla and subphyla within the clade Ecdysozoa, which includes animals with tough outer coverings that must be shed for growth to occur. Myriapods, cheliceriforms, crustaceans, and insects and their relatives (hexapods) together comprise the phylum Arthropoda, which is marked by jointed appendages, segmented bodies, and hard exoskeletons. Note that the tree does not show all phyla in the clade Ecdysozoa, nor does it show all orders of insects and their relatives in the subphylum Hexapoda.
If a lung were to be found in a mollusc, where would it be located?
MANTLE CAVITY
Members of the phylum Mollusca
Members of the phylum Mollusca are soft-bodied and are often covered by a shell.
Some species of rotifers consist solely of females. Their method of reproduction is described as
PARTHENOGENESIS The females lay unfertilized eggs that develop into females.
Which of the following is a characteristic of all chordates at some point during their life cycle
POST-ANAL TAIL
The animal phylum most like the protists that gave rise to the animal kingdom is _____.
PROIFERA Evidence that supports this includes the lack of true tissue in sponges and the close similarity between choanocytes and choanoflagellates.
Which structure can be used for feeding and gas exchange?
Pharyngeal gill slit A pharyngeal gill slit is an opening into the throat that can be used for feeding and gas exchange.
Which of the following are thought to be most closely related to humans
SEA STARS Humans and sea stars are deuterostomes.
What would be the most direct effect of removing or damaging an insect's antennae? The insect would have trouble
SMELLING
One should expect to find cilia associated with the feeding apparatus of
SPONGES
Which characteristic distinguishes echinoderms from the other two deuterostome lineages?
THE BODY PLAN Echinoderms exhibit a unique body plan characterized by an endoskeleton and a water vascular system.
Which of these are amniotes
TURTLES
Vertebrates and tunicates share
a notochord and a dorsal, hollow nerve cord
Which of the following could be considered the most recent common ancestor of living tetrapods?
a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates
Which of the following chordates is most likely to look least like other chordates
adult tunicate An adult tunicate does not have a notochord (or vertebrae), a nerve cord, or a post-anal tail. The only chordate feature it retains is pharyngeal slits.
Most members of which of the following groups are most closely associated with a wet or moist environment
amphibians Amphibians typically have a water-permeable skin that does not easily resist drying. Thus, amphibians tend to be found in moist environments.
You find a multi-legged animal in your garden and want to determine if it is a centipede or a millipede. You take the animal to a university where a myriapodologist quickly tells you that you have found a centipede. Which of the following may have allowed her to make this distinction
poisonous fangs
Which characteristic is common to all the modern representatives of all major reptilian lineages (turtles, lepidosaurs, crocodilians, and birds)?
presence of a notochord
What would be the most effective method of reducing the incidence of blood flukes in a human population
reduce the population of the intermediate snail host
Which of these traits is most strongly associated with the adoption of bipedalism
repositioning of foramen magnum
Which structure of the amniotic egg most closely surrounds the embryo
the amnion
Which of these characteristics added most to vertebrate success in relatively dry environments?
the shelled, amniotic egg
Which one of these chordate groups lacks a post-anal tail and a notochord as adults
tunicates While larval tunicates have a post-anal tail and a notochord, adult tunicates do not.
Which of the following is NOT a diagnostic feature of the Chordata
vertebrae Lancelets and tunicates are two subgroups of chordates that lack vertebrae. Hagfishes do, too.