29: Amniote origins and evolution

Choose the two forms of nitrogenous waste that can be excreted in concentrated urine because of their lower toxicity. Urea Uric acid Ammonia

Urea Uric acid

What do reptiles excrete?

Uric acid

What extraembryonic membrane of the amniotic egg forms a sac where metabolic wastes are stored? Amnion Chorion Allantois Yolk sac

Allantois

What is found in eggs of both anamniotes and amniotes? Yolk sac Allantois Amnion Chorion

Yolk sac

A _______________ skull has a single temporal opening behind the orbit. The opening is usually located low on the cheeks and bordered by a single bony __________________.

synapsid; arch

The jaws of amniotes are much stronger than those of fishes. This is due to some extent to the expansion of jaw muscles into _____________ openings or notches of the skull.

temporal

Color-bearing cells called ______ are present in the dermis of many lizards and snakes. colloblasts collencytes osteoderms chromatophores

chromatophores

Nonavian reptiles have metaneprhic kidneys and empty their metabolic wastes to the outside through their ________________.

cloaca

All reptiles, except crocodilians, posses a single _____________ in their heart, which is incompletely partitioned into multiple chambers.

ventricle

In terms of the source of heat used to regulate their body temperature, nonavian reptiles are ______. homeothermic endothermic ectothermic

ectothermic

Nonavian reptiles use external sources of heat in order to regulate their temperature; therefore, they are ______________.

ectothermic

The evolution of the shelled egg allowed reptiles to become fully independent from the aquatic environment because a shelled egg ______. is a requirement to have efficient internal fertilization encloses a small aquatic environment, where development of the embryo can occur can be buried in the ground and still allow for embryo survival

encloses a small aquatic environment, where development of the embryo can occur

What sense is particularly well developed in most nonavian reptiles and birds? Smell Hearing Vision

vision

In all nonavian reptiles, the skull is connected to the first vertebra ______. with two occipital condyles with a single condyle without occipital condyles

with a single condyle

The systemic blood pressure of amniotes is ______ that of amphibians. very similar to higher than lower than

higher than

What do amphibians excrete?

Ammonia

What statement accurately compares the lungs of amniotes with those of amphibians? - Amniote and amphibian lungs have similar surface area, but are ventilated by different mechanisms. - Amniote lungs have much more surface area and are ventilated by a different mechanism. - Amphibian lungs have much more surface area and are ventilated by a different mechanism.

Amniote lungs have much more surface area and are ventilated by a different mechanism

Choose all the features that distinguish the amniote skin from that of amphibians. Amniote skin allows for better gas exchange in air. Amniote skin is thinner. Amniote skin is more keratinized. Amniote skin is less permeable to water.

Amniote skin is more keratinized Amniote skin is less permeable to water

Amniotes with skulls that have no openings in the temporal area (behind the opening for the eye) are known as __________________.

Anapsid

What type of skull has a temporal region with no fenestrae and is completely roofed by dermal bones? Diapsid Therapsid Synapsid Anapsid

Anapsid

__________________ were a group of anamniotes of the Carboniferous period that are most closely related to early amniotes.

Anthracosaurs

What amniotes can supplement their pulmonary respiration with respiration at their pharynx or cloaca? Some species of crocodiles Certain species of freshwater snakes All lizards Aquatic turtles

Aquatic turtles

Early diapsids diversified to give rise to five morphologically distinct clades. What clade includes dinosaurs, pterosaurs, crocodilians, and birds? Pelycosaurs Sauropterygians Lepidosaurs Archosaurs

Archosaurs

As traditionally defined, reptiles are a paraphyletic group because they don't include all of descendants of their most common ancestor. Which group of animals has to be added to the traditional reptile group in order to produce a monophyletic clade? Birds Egg-laying mammals Crocodilians Amphibian-like reptiles

Birds

What is a separate monophyletic group within the reptiles (as defined by modern cladistics)? Snakes and crocodilians Birds and crocodilians Birds and lizards

Birds and crocodilians

What amniotes can resorb water and salts from dilute urine in their bladder? Birds and mammals Birds only Mammals and nonavian reptiles Birds and nonavian reptiles

Birds and nonavian reptiles

Choose the two extraembryonic membranes that act as a respiratory organ for the embryo in an amniotic egg. Chorion Shell Yolk sac Allantois Amnion

Chorion Allantois

A ______________ skull has two temporal openings that are separated by a bony arch.

Diapsid

Select all of the situations in which the incomplete separation of blood in the heart of nonavian reptiles is an advantage. During swallowing of a very large prey item During diving During estivation During active prey pursuit

During diving During estivation

True or false: All amniotes have very acute senses of vision, smell, and hearing.

False

True or false: Amniotes and amphibians ventilate their lungs in the same way.

False

True or false: Nonavian reptiles have non-nucleated red blood cells.

False

Diapsids first appeared during the Paleozoic and subsequently diversified into five distinct clades. The __________________ are an extinct clade represented by aquatic, dolphin-like species.

Ichthyosaurs

What statement describes the separation of blood in the atria of amniotes? - In all amniotes, blood in the left atrium is completely separated from blood in the right atrium. - In all amniotes, blood in the left atrium is incompletely separated from blood in the right atrium. - In all amniotes, except crocodilians, blood in the left atrium is incompletely separated from blood in the right atrium.

In all amniotes, blood in the left atrium is completely separated from blood in the right atrium

Select all of the selective advantages of the amniotic egg when compared with the egg of amphibians. It supplies nutrients via a smaller yolk sac. It can support larger embryos. It can be laid in drier environments. It has better movement of oxygen.

It can support larger embryos It can be laid in drier environments It has better movement of oxygen

Select all of the features of the amniote jaw and mouth. It is designed for suction feeding. It is stronger than that of fishes. It is a muscular, mobile tongue.

It is stronger than that of fishes It is a muscular, mobile tongue

Select all of the features of the mineralized egg shell in birds. It provides mechanical support. It accumulates metabolic wastes. It cushions the embryo. It limits water loss. It allows gas exchange.

It provides mechanical support It limits water loss It allows gas exchange

A fossil skull of an amniote has two temporal openings, one above the other, separated by a small bony arch. Select all of the following that can be concluded about this ancient amniote. It could have been a turtle. It was a synapsid. It was a diapsid. It could have been a lizard. It could have been a mammal.

It was a diapsid It could have been a lizard

In the skin of amniotes, ______ provides protection from physical trauma, while ______ lipids limit the loss of water. elastin; hydrophobic keratin; hydrophobic keratin; hydrophilic elastin; hydrophilic

Keratin; hydrophobic

Choose the two sister clades within the Reptilia, as defined by modern cladistics. Lepidosaurs Trissaurs Archosaurs Pelycosaurs

Lepidosaurs Archosaurs

Select all of the amniotes that have synapsid skulls. Therapsids Mammals Lizards Birds Crocodilians

Mammals Therapsids

What accurately describes turtles and their classification? Modern turtles have diapsid skulls, which, when combined with genetic and morphological evidence places them within the diapsid clade. Modern turtles have anapsid skulls, however, genetic and morphological evidence placed them within the synapsid clade. Modern turtles have anapsid skulls, however, genetic and morphological evidence places them within the diapsid clade.

Modern turtles have anapsid skulls, however, genetic and morphological evidence places them within the diapsid clade

Choose all functions of the amnion in the amniotic egg. provides a respiratory surface for carbon dioxide removal and oxygen acquisition provides an aquatic environment for embryo development cushions the embryo provides mechanical support to the egg, while protecting the egg from dehydration

Provides an aquatic environment for embryo development Cushions the embryo

What is an example of an amniote that can exchange gases in areas other than their lungs? Sea snakes primarily use their skin to exchange gases. Many lizards can exchange gases though special skin flaps on the chin. Some crocodiles can exchange gases through highly vascularized tissues in their cloaca.

Sea snakes primarily use their skin to exchange gases

Select all shared derived characters that unite birds and nonavian reptiles as a monophyletic group. Skull and ankle features Good sense of vision Presence of four limbs Beta keratin in the skin

Skull and ankle features Beta keratin in the skin

Why do all amniotes have internal fertilization? - The embryo has to develop inside the female parent before an egg can be laid or the offspring can be born. - All amniotes have copulatory organs that deliver the sperm to the egg. - Sperm cannot penetrate the shell and extraembryonic membranes.

Sperm cannot penetrate the shell and extraembryonic membranes

What part of the amniotic egg provides mechanical support and can, in certain animals, act as a semipermeable barrier that allows gases in and out, but keeps the egg from drying out? The pit organ The shell The yolk sac The allantois

The shell

What part of the amniotic egg provides mechanical support and can, in certain animals, act as a semipermeable barrier that allows gases in and out, but keeps the egg from drying out? The shell The pit organ The allantois The yolk sac

The shell

What describes the flow of blood in the ventricle of reptiles (except crocodilians)? - The ventricle is incompletely partitioned, but flow patterns limit the mixing of oxygenated and deoxygenated blood - The ventricle is incompletely partitioned, which results in significant mixing of oxygenated and deoxygenated blood - The atrium is completely partitioned, so there is no mixing of oxygenated and deoxygenated blood

The ventricle is incompletely partitioned, but flow patterns limit the mixing of oxygenated and deoxygenated blood

What is the function of the temporal openings found in modern animals with synapsid and diapsid skulls? They are occupied by large muscles that elevate the lower jaw They are occupied by specialized parts of the brain not found in animals without those openings They allow thick nerves to exit the brain and innervate muscles that operate the jaws

They are occupied by large muscles that elevate the lower jaw

Choose the features of teeth in a typical nonavian reptile (except turtles, in which teeth are absent). They cannot be replaced if lost. They have a single point. They can be replaced many times during lifetime. They are similar in shape and function. They are well differentiated in shape and function. They have two or more points.

They can be replaced many times during lifetime They are similar in shape and function They have a single point

What do mammal excrete

Urea

Select all of the ways in which amniotes can fill their lungs. They use rib muscles. They pull their liver posteriorly. They reduce the volume of their thoracic cavity. They push air from the oral cavity into the lungs.

They use rib muscles They pull their liver posteriorly

In the amniotic egg, the extraembryonic membrane called the __________________ encloses the embryo in fluid, therefore providing an aquatic environment, in which the embryo can develop

amnion

The four extraembryonic membranes of the amniotic egg are: the ________________, the _____________, the _____________, and yolk sac.

amnion, allantois, chorion

The amnion, chorion, allantois, and the yolk sac are the four extraembryonic membranes found in ____________________ eggs.

amniotic

If the systemic blood pressure of a vertebrate is about 80 mm Hg, this vertebrate is most likely ______. an amniote a bony fish an amphibian

an amniote

Early amniotes are most closely related to a group of anamniotes of the early Carboniferous period. This group of anamniotes is the ______. ichthyosaurs pelycosaurs anthracosaurs therapsids

anthracosaurs

As traditionally classified, reptiles are a paraphyletic group because birds are not included, and birds ______. are descended from the same ancestor as reptiles have features that are similar to those of reptiles were the ancestors of all reptiles

are descended from the same ancestor as reptiles

Nonavian reptiles (except turtles) have polyphyodont teeth, which means that their teeth ______. have multiple points are replaced many times have different shapes and functions

are replaced many times

In the amniote heart, the left ___________________, which receives oxygenated blood from the lungs, is completely separated from the right one, which receives deoxygenated blood from the body.

atrium

The special, hardened, form of keratin that is found in the epidermis of class Reptilia is called ______ keratin. alpha osteodermal dermal beta

beta

Because they share several derived characters, such as the presence of ____________ keratin in the skin, birds and nonavian reptiles are united as a ________________ clade.

beta; monophyletic

Beta keratin is a hard form of kertain found in the epidermis of what amniotes? Select all that apply. marsupial mammals birds nonavian reptiles placental mammals

birds nonavian reptiles

In birds and nonavian reptiles, water and many salts from dilute urine are resorbed in the ______. gizzard intestines cloaca bladder

bladder

Genetic and morphological evidence suggests that even though modern turtles have anapsid skulls, they evolved from animals with ___________________ skulls.

diapsid

During diving, a reptilian's ______________ separation of blood in the heart ventricles can be advantageous, as it allows blood to bypass the _________________, when pulmonary respiration is not occurring.

incomplete; lungs

The presence of extraembryonic membranes and, in many cases, a shell, would prevent the sperm from reaching the egg. For that reason, all amniotes have _____________ fertilization.

internal

Scales, feathers, hair, and claws are skin structures found in amniotes that are composed of ________________.

keratin

Scientists hypothesize that one reason why temporal openings evolved in amniotes was to accommodate large ______________, which can elevate the lower _________________. These changes might have reflected a switch from suction feeding in aquatic vertebrates to terrestrial feeding in early amniotes.

muscles; jaw

Bony plates called __________ are found in the dermis of crocodiles and many lizards, underneath the keratinized scales.

osteoderms

The lower jaw of nonavian reptiles is made of ______. a single bone one or two bones several bones

several bones

The ______ of early amniotes allowed those animals to fully live on land because it provided an enclosed aquatic environment, in which an embryo can develop. external gills spermatophore eft stage shelled egg

shelled egg

Scientists hypothesize that early amniotic eggs had a selective advantage and were able support larger and faster-growing embryos than eggs of amphibians because ______. their shells provided better support and movement of oxygen they were the first eggs that could be laid on land where temperature was cooler than in the water amniotic eggs stored water in the larger shell instead of in the yolk sac

their shells provided better support and movement of oxygen

Amniote animals fill their lungs by expanding their _______________ cavity, using their rib muscles, or by pulling the diaphragm or ________________ posteriorly with other muscles

thoracic; liver

True or false: In contrast to amphibians, the skin in most amniotes does not participate in the exchange of gases.

true

In an amniotic egg, nutrients are stored in the ______. amnion yolk sac allantois chorion

yolk sac