Ch 34 Chordates - Amphibians Flashcards Preview

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Flashcards in Ch 34 Chordates - Amphibians Deck (48):
1

Lobe-finned fishes include what two living groups?

1) Actinistia
2) Dipnoi

2

Actinistia and Dipnoi have some characteristics of what?

The hypothetical first terrestrial vertebrates

3

Latimeria

Lobe-finned fish within the Actinistia

4

Latimeria possessed what?

Paired fins at the end of appendages with internal body elements

5

Lungfish retain what?

A prominent notochord (but have well-developed vertebrae as well)

6

Do lungfish possess functional lungs?

Yes

7

Lungfish can withstand what?

Drying in their habitat

8

When conditions of their environment require it, lungfish can enter what?

Estivation

9

Estivation

A state of reduced physiological activity during drought

10

How long can lungfish remain in estivation?

7 to 8 months

11

Characteristics of estivation

1) Air-breathe
2) Lower heart rate
3) Retain urea and other wastes
4) Catabolize body (lose weight)

12

Tetrapods

Ancestrally terrestrial and four-limbed vertebrates

13

What is the earliest diverging living group of the tetrapods?

Amphibia

14

Benefit(s) for chordates on land

O2 is 20 times more concentrated in air than in water

15

Difficulties for chordates on land

1) Air is 1,000 times more dense than water
2) Air is 50 times less viscous than water
3) Air experiences far grater temperature extremes
4) Terrestrial environments comprise a much greater diversity of habitats than do marine environments

16

Three body forms of amphibians

1) Frogs
2) Salamanders
3) Caecilians

17

How many species of amphibians are there?

6,000

18

Modern amphibian skeletal system

Skeleton is mostly bone

19

How many limbs do most amphibians have?

Four

20

Characteristic of amphibian skin

Very moist

21

Function of amphibian skin

Functions in respiration

22

Salamanders

Tailed amphibians

23

Are all amphibians endotherms or ectotherms?

Ectotherms

24

What is the ancestral condition of the salamander life cycle?

Metamorphosis from aquatic larva to terrestrial adults

25

How are salamander eggs fertilized?

Internally via a spermatophore passed to the female

26

Spermatophore

A packet of sperm

27

Newt life cycle

Have an aquatic larva followed by a terrestrial juvenile stage then by a second adult aquatic stage

28

Paedomorphosis

The evolution of retention of larval characteristics into adulthood

29

Many salamanders achieve sexual maturity while retaining what?

External gills and an aquatic habitat

30

What allows for cutaneous respiration in all amphibians?

Extensive nets of blood vessels in the skin

31

At various life stages, salamanders may have what?

Gills, lungs, both, or neither

32

How do some salamanders capture prey

Via ballistic tongue projection

33

Anurans

Frogs and toads

34

How many species of anurans are there?

5,200

35

Anurans are primarily adapted for what kind of locomotion?

Jumping locomotion

36

How are anurans adapted for jumping locomotion?

1) Reduction of vertebrae
2) Fusion of bones
3) Elongation of bones

37

What protein toughens that outer skin layer of anurans?

The protein keratin

38

What limits water loss in the skin of anurans?

Mucous glands

39

What kind of glands function in defense in anurans?

Toxin glands

40

Anurans have what kind of circulatory system?

An efficient, closed circulatory system

41

How many chambers does the heart of an anuran have?

Three

42

Two circuits of anuran circulation

1) Pulmonary (lung) circuit
2) Systemic (body) circuit

43

Do anurans have internal or external fertilization?

External

44

Anurans deposit huge masses of eggs where?

In aquatic habitats

45

How long can the process of metamorphosis in anurans take?

2-3 years

46

Apodans

Caecilians

47

Caecilians

Elongated, limbless, burrowing amphibians

48

How many species of apodans exist?

170