58 terms

Bio Animal 3

Vertebrates and tunicates share
a notochord and a dorsal, hollow nerve cord
What is one characteristic that separates chordates from all other animals?
dorsal, hollow nerve cord
Which of these are characteristics of all chordates during at least a portion of their development?
a dorsal, hollow nerve cord pharyngeal clefts, post-anal tail
Pharyngeal slits appear to have functioned first as
suspension-feeding devices
Unlike eutherians, both monotremes and marsupials
have some embryonic development outside the mother's uterus
Which extant chordate group is postulated to be most like the earliest chordates in appearance?
As humans diverged from other primates, which of the following appeared first?
a partial erect stance
Studies on DNA indicate which of the following?
Homo sapiens originated in Africa
Based on current evidence, which of the following statements best describes the evolution of humans?
humans and apes disverged from a common ancestor about 5-10 millions years ago
) The common ancestors of all humans alive today lived in Africa until about
50,000 years ago.
The common ancestor of all these chordate groups except the ________ probably had paired appendages
The earliest known mineralized structures in vertebrates are associated with which function?
The exoskeletons of marine arthropods are made of calcified ________, and the endoskeletons of vertebrates are mostly composed of calcified ________.
chitin: cartilage
How are primates different from all other mammals?
opposable thumbs in many species
In which vertebrates is fertilization exclusively internal?
reptiles and mammals
Which of these hominid traits seems to have occurred before the others?
In which extant class did jaws occur earliest
According to one hypothesis, the jaws of vertebrates were derived by the modification of
skeletal rods that had supported pharyngeal (gill) slits.
What is a distinctive feature of the chondrichthyans?
cartilaginous endoskeleton
To which of these are the scales of chondrichthyans most closely related in a structural sense?
chondrichthyan teeth
Which of these statements accurately describes a similarity between sharks and fishes?
they have a lateral line that is sensitive to changesin water pressure
Which group's members had (have) both lungs and gills during their adult lives?
The most primitive hominid discovered to date
walked on two legs
Which are the most abundant and diverse of the extant vertebrates?
bony fishes
The bony fishes are characterized by
a bony endoskeleton, aperculum, and usually a swim bladder
Which of these would a paleontologist be most likely to do in order to determine whether a fossil represents a reptile or a mammal?
Examine the teeth
All of the following belong to the lobe-fin clade, except
Structures that are made of keratin include which of the following?
avian feathers reptilian scales mammalian hair
Differentiation of teeth is greatest in
A trend in the evolution of the earliest tetrapods was
feet with digits
Examination of the fossils of Archaeopteryx reveals that, in common with extant birds, it had
Why is the discovery of the fossil Archaeopteryx significant? It supports the
phylogenetic relatedness of birds and reptiles
During chordate evolution, what is the sequence (from earliest to most recent) in which the following structures arose?

1. amniotic egg
2. paired fins
3. jaws
4. swim bladder
5. four-chambered heart
________ are the oldest known primate group
Why is the amniotic egg considered an important evolutionary breakthrough? It
allows incubation of eggs in aterrestrial environment
Which era is known as the "age of reptiles"?
Which of these characteristics added most to vertebrate success in relatively dry environments?
the amionic egg
From which of the following groups are snakes most likely descended?
When did dinosaurs and pterosaurs become extinct?
cretaceous "crisis"
Which of the following are the only extant animals that descended directly from dinosaurs?
the first of these species to have been adapted for long-distance bipedalism
C) anthropoids
the first of these species to craft stone tools
d) hominids
the first of these species to show a trend toward reduced sexual dimorphism
C) anthropoids
the first of these species to have some members migrate out of Africa
b) Homo
the species currently thought to be the direct ancestor of H. neanderthalensis
A) hominoids
the species that demonstrates symbolic thought, art, and full-blown language
E) primates
Which is the most inclusive (most general) group, all of whose members have foramina magna centrally positioned in the base of the cranium?
D) hominids
Which term is most nearly synonymous with "apes"?
A) hominoids
Which is a genus that has only one extant species?
B) Homo
Which is the most inclusive (most general) group, all of whose members have fingernails instead of claws?
E) primates
Which is the most inclusive (most general) group, all of whose members have fully opposable thumbs?
C) anthropoids
Which is the most specific group in which prosimians can be included?
E) primates
Which is the most specific group that includes both the Old World monkeys and the
C) anthropoids
their scales closely resemble teeth in both structure and origin
C. chondrichthyans
internal fertilization, amniotic egg, skin that resists drying, heavy bones
B. non-avian reptiles
three major groups: egg-laying, pouched, and placental
D. mammals
may have lungs, or gills, and may use skin as a respiratory surface
A. amphibians
honeycombed bones, females with one ovary, no teeth
E. avian reptiles