Deck 41: Reptiles

Question 1

Explain why scientists advocate the asteroid impact hypothesis for dinosaur extinction.

Answer 1

Dinosaurs are the extinct reptiles that existed and dominated the land about 235 million years ago (mya). They evolved from thecodonts (crocodile-like reptiles, now extinct) and adapted to different environments, for example, the pterosaurs could fly, ichthyosaurs and the plesiosaurs lived in oceans. The breaking-apart of the supercontinent Pangaea into separate landmasses resulted in the change of climates and thereby extinction of dinosaurs.
Triassic dinosaurs were the oldest dinosaurs which had existed about 235 mya. These were the small, carnivorous dinosaurs that had replaced the thecodonts. Their legs supported their body weight well and assisted them to run faster than the thecodonts. They were well adapted to the dryer climates of Pangaea in the Triassic period.
Dinosaurs were very successful animals of their times. There were many reasons, hypothesized by the scientists, as to why the dinosaurs became extinct.
Asteroid Impact Hypothesis suggests that the simultaneous hitting of the earth with asteroids ad meteorites containing rare metal Iridium resulted in the formation of craters on the earth that in turn, resulted in an increase in the amount of dust and iridium in the atmosphere. Due to dust, there was a decrease in the amount of sunlight reaching the earth, and hence, a severe climatic change that resulted in the mass extinction of many species, including the thecodonts and the large amphibians, at the end of the Triassic period. This event is also hypothesized to have resulted in the reduction of many dinosaurs.

Question 2

CONCEPT MAPPING Use the following terms to create a concept map that relates various adaptations of reptiles to life on land: reptiles , water loss , amniotic eggs , keratin , scales , watertight , and skin.

Answer 2

Amphibians required water for reproduction and therefore could not make a successful transition to the life on land. However, reptiles adapted to reproduce without the presence of water around. Reptiles evolved to produce amniotic eggs as an adaptation to life on land and became the first-ever successful terrestrial animals. Reptilian eggs are protected by a tough but porous shell and encased in a watery-sac called amniotic fluid, hence the name amniotic eggs. Amniotic eggs have 4 specialized membranes - amnion, yolk sac, allantois and chorion.
Amnion is the thin membrane that encloses the fluid containing the floating embryo. Yolk sac encloses a fat-rich food supply called the yolk for the developing embryo. The nitrogenous waste produced by the embryo is contained inside the allantois. Allantois also allows gaseous exchange with the blood supplied to the egg. Chorion encloses all the above 3 membranes and provides safety to the developing embryo.
Skin of the amphibians must be thin and moist to allow gaseous exchange. However, due to moist skin, the amphibians lose water by evaporation. To avoid water loss, the retles have evolved to have a thick, dry and scaly skin filled with keratin that makes the skin watertight. Tough skin helps in water conservation and prevents the animal against injury and infections.
The concept map showing various adaptations of reptiles to life on land are as follows:
FIGURE : Concept map

Question 3

Describe how reptiles inhale and exhale.

Answer 3

Reptiles form the largest group of vertebrates that inhabit the terrestrial and aquatic ecosystems. The primitive reptiles were small-sized, 4-legged, had teeth adapted to eat insects, and resemble lizards.
Phylogenetic analysis and study of fossils and anatomy suggests that the reptiles arose from the amphibians. Reptiles are differently sized and shaped, and therefore, they have different rates of metabolism and anatomical and physiological characteristics.
Reptiles have large lungs, which are divided into various chambers. The linings are folded into multiple sacs, called alveoli, to increase the surface area for absorption of oxygen. Alveoli are responsible in increasing the lung's internal surface area. This results in increasing the oxygen's amount, which can be absorbed. In many types of snakes, only one lung, that is, right lung actively functions.
The lungs of a reptile are filled by expansion of its rib cage. The pressure is reduced due to this expansion within the thorax, which results in the air to draw into the lungs. When the ribs are returned to the resting position, there is an increase in the pressure within the thorax. The air is then forced out of lungs. The same type of movements assists humans in the process of breathing.

Question 4

INTERPRETING GRAPIHCS: The illustration below shows a cross section of a turtle's heart. Use the illustration to answer the question that follows.

Which feature of a turtle's heart structure is different from that of a crocodile?

A) l
B) 2
C) 3
D) 4

Question 5

Analyzing Information If birds did not evolve from the pterosaurs, what can you conclude about the evolution of the ability to fly?

Question 6

Identify two sense organs reptiles and amphibians share and two sense organs that are unique to reptiles.

Question 7

Choose the term that does not belong in the following group, and explain why it does not belong: elapids , vipers , constrictors , and dinosaurs.

Question 8

Name one example of each of the four modern orders of reptiles.

Question 9

Analyzing Concepts Why is it advantageous for a snake to kill its prey, either through constriction or venom, before trying to eat the prey?

Question 10

Compare thermoregulation in animals that are endothermic versus thermoregulation in animals that are ectothermic.

Question 11

There are three patterns of reproduction among reptiles. They differ in how long eggs remain in the female and how the developing young are provided with nutrition.
Part A With these differences in mind, compare oviparity, ovoviviparity, and viviparity.
Part B In which pattern of reproduction is a placenta present? Explain the function of the placenta.

Question 12

Explain how the evolution of the amniotic egg is an adaptation to life on land.

Question 13

Recognizing Relationships The skin of a basking lizard is usually dark. As the lizard warms, the skin lightens. Suggest a functional explanation for this change. (Hint: Consider how this change might affect the lizard's absorption of heat.)

Question 14

Contrast oviparity with viviparity.

Question 15

A reptile can redirect blood flow through the heart to send some deoxygenated blood back to the body instead of to the lungs.
What is the advantage to the lizard of redirecting blood flow in this manner?

Question 16

Explain how the respiratory and excretory systems in reptiles show adaptations for life on land.

Question 17

Analyzing Data Fossil evidence collected in Alaska suggests that some dinosaurs were year-round residents of areas subject to freezing temperatures and long periods of darkness. Does this evidence of arctic dinosaurs support or contradict the hypothesis that the extinction of dinosaurs was due to the intense cold produced by a cloud of debris in the atmosphere? Explain your answer.

Question 18

Applying Information Which of the patterns of reproduction in reptiles best serves to protect the eggs from predators? Explain.

Question 19

DIRECTIONS: Choose the letter of the answer choice that best answers the question. Which is an adaptation that made reptiles the dominant species in the Mesozoic era?

A) They were endotherms.
B) They could live in Antarctica.
C) They were all large predators.
D) They were well adapted to dry areas.

Question 20

Contrast a turtle's heart and a crocodile's heart.

Question 21

Relating Concepts Some viviparous snakes and lizards live in cold climates. Why might viviparity be advantageous in such environments?

Question 22

Making Comparisons Both crocodiles and turtles are ectothermic. Why do you think crocodile hearts are different from turtle hearts?

Question 23

Explain the relationship between amnion and chorion.

Question 24

Describe how the structure of a turtle's heart allows for flexibility in blood circulation.

Question 25

Interpreting Graphics The following diagram shows five parts of the amniotic egg, indicated by the letters A, B, C, D, and E. Name and identify the function of each part.

Question 26

Justifying Conclusions Would change in body temperature over the course of a day prove that an animal is an ectotherm? Why or why not?

Question 27

What are the two basic parts of a turtle's shell?
F) septum and amnion
G) chorion and allantois
H) keratin and columella
J) carapace and plastron

Question 28

Identify the advantage of alveoli in respiration.

Question 29

Explain the role of climate in the success of early reptiles.

Question 30

Compare the characteristics of aquatic turtles to the characteristics of land tortoises.

Question 31

Use each of the following terms in a separate sentence: oviparity , ovoviviparity , and viviparity.

Question 32

Describe two senses other than vision and hearing that reptiles use to find prey.

Question 33

Compare and contrast characteristics of Triassic and Jurassic dinosaurs.

Question 34

Identify characteristics of crocodilians that allow them to feed efficiently in water.

Question 35

What is the purpose of a lizard's ability to lose its tall and grow a new one?

A) to capture prey
B) to hide from predators
C) to escape from predators
D) to reduce its need for food

Question 36

Identify the major benefit of ectothermy.

Question 37

Explain the importance of iridium found in sediments from the end of the Cretaceous period.

Question 38

Identify three strategies employed by lizards to avoid predators.

Question 39

Word Roots and Origins The word ectotherm comes from the Greek word ecto , meaning "outside" and therm , meaning "heat". The word endotherm comes from the Greek word endo , meaning "within" and therm , meaning "heat". Explain why each term is a good name for the biological process that the term describes.

Question 40

Compare the reproductive strategies of oviparity, ovoviviparity, and viviparity.

Question 41

Summarize the two asteroid impact hypotheses.

Question 42

Describe two methods snakes use for killing prey.

Question 43

Long legless bodies may have arisen as an adaptation that helped snakes do what?
F) catch prey
G) swallow large animals
H) absorb oxygen through their skin
J) burrow and move through thick vegetation

Question 44

Describe the features that make turtles unique among reptiles.

Question 45

Describe three characteristics that contribute to the success of reptiles on land.

Question 46

Explain why tuataras are rarely seen in the wild.

Question 47

Summarize the events that led to the rise of reptiles during the Permian period.

Question 48

Explain how crocodilians swallow prey underwater.

Question 49

Analyzing Information Why might dinosaurs have survived the asteroid impact at the end of the Triassic period but not one at the end of the Cretaceous?

Question 50

Making Comparisons Compare the costs versus the benefits of autotomy for lizards.

Question 51

INTERPRETING GRAPIHCS: The graph below shows changes in air temperature and changes in the body temperature of a lizard. Use the graph below to answer the question that follows.

In order for the lizard to raise its internal temperature it must do which of the following?

A) rest in the shade
B) bask in sunshine
C) increase its internal temperature through activity
D) decrease its internal temperature through activity

Question 52

Explain the purpose of a lizard's ability to lose its tall and grow a new one.

Question 53

Relating Concepts Dinosaurs are now thought to have been warmblooded. How does this support the theory about their relationship to birds?

Question 54

Question 55

Identify three factors that contributed to the success of dinosaurs during the Triassic period.

Question 56

List three ways in which snakes can inject venom into their prey.

Question 57

Inferring Relationships In what ways are the adaptations of reptiles to land similar to the adaptations of plants to land?

Question 58

Applying Information Why do you think snakes have many more vertebrae than any other group of reptiles does?

Question 59

DIRECTIONS: Complete the following analogy. Ectotherm : reptiles :: endotherm :
F) fishes
G) insects
H) mammals
J) amphibians

Question 60

Identify the reason populations of tuataras have decreased in the last 1, 000 years.

Question 61

Describe how the heart of a turtle differs from the heart of a crocodile.