Like this study set? Create a free account to save it.

Sign up for an account

Already have a Quizlet account? .

Create an account

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

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

Voice Recording