Deck 40: Amphibians

Question 1

DIRECTIONS: Choose the letter that best answers the question or completes the sentence. Amphibians must lay eggs in water primarily for what reason?
F) The eggs are not laid in nests.
G) The eggs need oxygen from water.
H) The eggs need protection from predators.
J) The eggs do not have multicellular membranes and a shell.

Answer 1

The mode of fertilization in the amphibians is external, which means that both the male as well as the female frogs release gametes in water. These gametes then fuse, and ultimately fertilization takes place.
Many species of frogs are known to build nests for the fertilized eggs, in order to provide parental care and to avoid predators. However, even in these species, the fertilization is strictly external and water is required.
The eggs do not have an active metabolism. All the nutrients required by the growing embryo are provided by the yolk that is present within the egg. When the eggs are in water, they have a high chance of attack from the predators. In order to protect from predators, frogs employ different strategies. One of these is building a nest.
Hence, the options F, G, and H are incorrect.
The eggs of the amphibians, unlike those of reptiles and higher vertebrates, lack a shell and multicellular membranes. In order to keep the egg moist it is extremely important that it should be surrounded by water. Therefore, amphibians need to lay their eggs in water.
Hence, the correct answer is option
.

Question 2

Explain how an amphibian's nervous system is similar to that of a bony fish.

Answer 2

Amphibians are the animals that can live on land as well as in water. Amphibians are organisms that are believed to be evolved from fishes that are the first water animals on earth, and specific species that is believed to be the ancestors of the amphibians is the sarcopterygian.
Fish and amphibians both have a brain and a spinal cord that are part of CNS (central nervous system), which helps them to have a more complex interaction with their environment.
Bony fishes have an optic lobe and a cerebellum. As they live in water, they have an organ known as lateral line to detect presence of water. This allows them to determine the position of their prey and its motion. Bony fishes have only inner ear but no outer ear. Therefore, they are only able to sense some vibrations. Fishes living in shallow areas have eyes and can detect light, whereas fishes in deep sea are devoid of eyes as there is no light coming there.
Larvae of amphibians living in aquatic environment also have a lateral line. But as an adult, they lose their lateral line and develop olfactory bulbs to adapt themselves on the life of land. Adults living on land have well developed organ of taste, touch, smell (nasal epithelium), vision (eyes) and hearing (tympanum with external ear).

Question 3

Forming Reasoned Opinions Is the lack of legs a primitive characteristic for amphibians or a later amphibian adaptation? Support your answer.

Answer 3

Order is the Gymnophiona that includes caecilian as the sole members of this order. Caecilians are also known as the limbless amphibians. They are blind and only few species have the vision power that is why they are mostly found in the soil or are exclusively under born and due to this reason very less is known about their ecology and behavior. They are also carnivorous and they eat the small insects and invertebrates, which they find with the help of chemosensory process.
This group always lacks legs and the young ones of the caecilian use their jaws and teeth to scrape secretions from the female reproductive tract that is often termed as the uterine milk. After the young ones become adult enough to be responsible then the mother dies and they for that time the off springs used to eat the body of the caecilian.
It is a matter of fact that evolution is a unidirectional process, slow and gradual as well. This unidirectional way of passing genetic information means that what is left behind cannot be taken back. Therefore, the limbless nature of organism in Amphibia class is observed in the Gymnophiona class.
Thus, the next there is no class in Amphibia group because advanced to amphibians there are reptiles, which are also limbless mostly. Therefore, we can say that limbless nature of amphibians is later adaptation to that of the reptiles and therefore, the snakes are limbless making the process of evolution unidirectional.
Caecilians are also known as snakes, as they do not have limbs and walk with the help of scales and muscles present in the body. They also have fangs that are actually teeth that the caecilians used to have. These are the examples that support the limbless nature to be the later adaptation in evolution.

Question 4

Recognizing Relationships How do you think the number of eggs produced by amphibians relates to the amount of parental care invested?

Question 5

Explain the relationship between preadaptation and adaptation.

Question 6

Explain how male frogs attract the attention of female frogs during mating season.

Question 7

Analyzing Information Why do modern amphibians not have a lateral line?

Question 8

Justifying Conclusions Would you expect an amphibian that bypasses the larval stage to produce more or less thyroxine? Explain.

Question 9

DIRECTIONS: Choose the letter that best answers the question or completes the sentence. Metamorphosis must take place before amphibians are able to do what?

A) swim
B) live on land
C) respire with gills
D) feed themselves

Question 10

Describe the reproductive system of a frog.

Question 11

Identify an advantage and a disadvantage to the permeability of amphibian skin.

Question 12

Word Roots and Origins The word columella comes from the Latin columna , which means "pillar." Using this information, list two characteristics of this amphibian ear bone.

Question 13

Discuss the life cycle of a frog.

Question 14

Explain three ways in which a frog's skeleton is adapted for jumping.

Question 15

INTERPRETING GRAPHICS: The figure below shows a longitudinal section, dorsal view, of a frog heart. Use the figure below to answer question 4.

Identify the source of blood flow in the section of the heart labeled 1.
F) the body
G) the aorta
H) the lungs
J) both lungs and body

Question 16

Contrast the physical characteristics of a larval frog to those of an adult frog.

Question 17

Identify the relationship between the structure of a frog's heart and "double-loop" circulation.

Question 18

Discuss the preadaptiations important in the evolution of amphibians.

Question 19

Describe two different examples of parental care found in frogs.

Question 20

Explain how a frog uses positive pressure to move air into and out of its lungs.

Question 21

DIRECTIONS: Complete the following analogy. Anura : frogs :: Gymnophiona :

A) toads
B) newts
C) caecilians
D) salamanders

Question 22

CONCEPT MAPPING Use the following terms to create a concept map that shows the methods of respiration in frogs: frogs , skin , mouth floor , body wall muscles , nostrils , lungs , air pressure , oral cavity , environment.

Question 23

What feature do the digestive and excretory systems in frogs have in common?

Question 24

Identify two characteristics that indicate that amphibians are descendants of ancient lobe-finned fish.

Question 25

Inferring Relationships Charles Darwin noticed that frogs and toads are often absent from oceanic islands, such as the Galapagos Islands, even though they may be found on the nearby mainland. Darwin conducted some experiments that showed that frogs' eggs cannot tolerate exposure to salt water. What hypothesis do you think Darwin was trying to test?

Question 26

Applying Information Which are the two largest features of an amphibian's brain? Why do you think these lobes are the largest?

Question 27

INTERPRETING GRAPHICS: The figure below shows an artist's rendering of Ichthyostega. Use the figure to answer the question that follows.

Ichthyostega is an early amphibian. Which of the following characteristics is most likely to help it live on land?
F) fishlike tail
G) seven-toed feet
H) four strong limbs
J) lateral-line canals on the head

Question 28

Recognizing Relationships In the brains of amphibians, the largest parts are the olfactory lobes and the optic lobes, the centers of smell and sight. This is very important to amphibians in hunting prey and avoiding predators. Why else is the capacity for hearing important?

Question 29

Making Comparisons Which sense organ of a terrestrial amphibian resembles the fish's lateral line in function? Explain your answer.

Question 30

Name five major characteristics of amphibians.

Question 31

Recognizing Relationships The female gastric-brooding frogs of Australia did not produce stomach acid or digestive enzymes while brooding their young in their stomachs until the tadpoles completed metamorphosis and left. If the mother frog did not eat during this period, from where did she get her energy?

Question 32

Recognizing Relationships Why are the skeletal bones in a frog's shoulders thicker than the bones in a frog's pelvic girdle?

Question 33

Identify the order to which each of the following belong: frogs, salamanders, caecilians.

Question 34

Analyzing Graphics When tadpoles undergo metamorphosis, their bodies begin to produce an enzyme that converts ammonia into urea. The time that a tadpole takes to produce this enzyme varies among species. In the graph below, the rate of enzyme production is shown for a species that inhabits a desert-like environment and a species that inhabits a forest environment. Which curve represents which frog? Explain.

Question 35

Identify two functions of the male frog's call.

Question 36

For each pair of terms, explain how the meanings of the terms differ.
A. systemic circulation and pulmonary circulation
b. amplexus and metamorphosis
c. pulmonary respiration and cutaneous respiration

Question 37

Explain how some species of frogs survive in desert environments even though they do not have watertight skin.

Question 38

Describe three adaptations that allowed early sarcopterygians to move onto land.

Question 39

Sequence the stages of a frog's life cycle.

Question 40

Frogs breathe by a positive pressure system.
Part A Describe how frogs move air into their lungs. Which part of inhaling is "positive pressure?"
Part B Describe how frogs move air out of their lungs and into the atmosphere.

Question 41

Relate the adaptations in the amphibian skeleton to the change in gravity with life on land.

Question 42

Identify two characteristics that amphibians share with modern lobe-finned fishes.

Question 43

Identify the features that are lost and the features that are gained during metamorphosis in frogs.

Question 44

Modem amphibians are a diverse group, but they do have some common characteristics.
Describe five key characteristics shared by modern amphibians.

Question 45

Outline the route of blood flow through the body of a frog, beginning with the right atrium.

Question 46

Name five key characteristics that are common to modern amphibians.

Question 47

Name the hormone responsible for stimulating tadpoles to undergo metamorphosis.

Question 48

DIRECTIONS: Choose the letter that best answers the question or completes the sentence. The forelimbs of vertebrates evolved from which structures in lobe-finned fishes?

A) anal fin
B) pelvic fins
C) pectoral fins
D) pectoral girdle

Question 49

Determine the next step for air within the oral cavity of a frog when it closes its nostrils and raises the mouth floor.

Question 50

Differentiate each of the three living orders of amphibians.

Question 51

Describe two strategies that have been found in frogs for protecting eggs and developing young.

Question 52

Use the following key terms in the same sentence: duodenum , mesentery and ileum.

Question 53

Trace the digestive process as food passes through a frog's digestive system.

Question 54

Applying Information Early amphibian fossils do not indicate the presence of lungs. Why do scientists think that early amphibians had lungs?

Question 55

Applying Information Why is standing water not always necessary for frog reproduction?