Which of the following designations applies to four-legged “crown group” descendants in the sarcopterygian lineage. Recall that crown group refers to four-legged extant animals and their closest common ancestor.

In their feeding habits, most adult amphibians are _______.

The structures responsible for color and color changes in amphibian skin are _______.

When the amphibians first moved onto land, there was _______.

True toads belong to the family _______.

Salamanders belong to the amphibian order _______.

The skin of amphibians is _______.

Larval amphibians are usually __________ in their feeding habits.

Gas exchange across the skin is called _______.

The outermost structure of the ear of anuran amphibians is the _______.

Because amphibians depend on external sources of heat to maintain body temperatures, they are said to be _______.

Most living nonavian reptiles are _______.

Sea turtles use ________ as an aid to navigation to nesting beaches.

Lizards belong to the suborder _______.

The dorsal portion of a turtle shell is called the _______.

Turtles belong to the reptilian order _______.

Members of three of the four living orders of reptiles are found on all continents except _______.

Reptiles have a skin with scales made of _______.

Lizards and snakes may lose their tails to escape from predators, this process is known as _______.

The skin of reptiles _______.

Early members of the reptiliomorph lineage were the first to produce _______.

This type of organism has been implicated in the recent global decline of amphibians.

All modern reptiles (including birds) are members of the _______ lineage. They are derived from ancestors that had upper and lower openings in the temporal region of the skull.

The skin of reptiles _______.

Snakes and lizards are superficially dissimilar. Which of the following is one reason that both are classified in the order Squamata?

Evidence seems to indicate that the feathered fossil form known as __________ was a glider rather than using flapping flight.

The traditional classification system places birds in the class _______.

The wings of a bird function as a(n) _______.

The __________ of most birds has a large, medial keel for attachment of flight muscles.

Which of the following features of birds is not an adaptation for flight?

The covering of feathers on a bird is called the _______.

All birds undergo a periodic replacement of their feathers during _______.

Albeit rare, a few bird species are ________________, in which females mate with more than one male.

The brain of a bird has a region called the __________ that regulates heart and respiratory rates.

Birds with long tongues include _______.

In many birds, a diverticulum of the esophagus, the __________, can be used to store large quantities of food.

Which of the following is least well developed in most birds?

__________ refers to periodic round trips between breeding and nonbreeding areas.

When birds fly, increased muscular activity produces large amounts of heat. Excess heat can be dissipated by _______.

A group of eggs laid by a female bird is called a _______.

The respiratory system of birds differs from that of most other reptiles. All of the following statements regarding gas exchange in birds versus other reptiles are true except one. Select the exception.

The most accepted explanation for the mass extinction event at the Cretaceous-Tertiary boundary is _______.

The beginning of the "age of mammals" coincides with the beginning of this period, about 70 million years ago.

The __________ are the "pouched" mammals.

A common opening for excretory, reproductive, and digestive products is called a _______.

Opossums belong to the group of mammals known as _______.

Which of the following is not a mammalian characteristic?

The duck-billed platypus and the echidna belong to the subclass _______.

__________ glands are functional in female mammals and are present, but nonfunctional, in males.

__________ glands are associated with hair follicles and secrete oil.

Mammalian teeth specialized for catching, killing, or tearing prey are _______.

The order of mammals with the largest number of species is the order

Bats are classified in the order _______.

Most mammals are _______.

Most mammals have two sets of teeth during their lifetime. The first set is called the __________ teeth.

Mammalian teeth specialized for gnawing or nipping are the _______.

In the rodents, the teeth known as __________ grow throughout life and have enamel only on their front surfaces.

A mammal that feeds on the flesh of another animal is called a(n) _______.

Animals that feed primarily on arthropods and other soft-bodied invertebrates are called _______.

Specializations of the digestive tract of most herbivores reflect the difficulty of digesting foods rich in _______.

Unlike reptiles and birds, mammals possess a muscular __________ that separates the thoracic and abdominal cavities.

The major excretory product of most mammals is _______.

The protein that accumulates to form claws, horns, hooves, and nails is _______.

Horses, rabbits, and many rodents have a(n) __________ that serves as a fermentation pouch where microorganisms aid in the digestion of cellulose.