Lab 7. Amphibia and Reptilia

Question 1

Amniotes

Answer 1

Produce amniotic eggs. Reptiles, aves, mammalia

Question 2

All tetrapods belong to what class

Answer 2

Class sarcopterygii

Question 3

3 orders of Amphibia (Lissamphibia)

Answer 3

1. Order gymnophiona
2. Order Caudata
3. Order Anura

Question 4

Order gymnophiona includes what

Answer 4

Caecilians (limbless, burrowing, almost blind)

Question 5

Order caudata includes what

Answer 5

Salamanders and newts

Question 6

Order anura/salienta includes what

Answer 6

frogs and toads

Question 7

4 orders of reptilia

Answer 7

1. Order testudines
2. Order crocodylia
3. Order Sphenodontida
4. Order Squamata

Question 8

Order testudines includes what

Answer 8

Turtles

Question 9

Order crocodylia includes what

Answer 9

Crocodiles, alligators, caimans, gavials

Question 10

Order sphenodontida includes what

Answer 10

tuataras (primitive, lizard-like reptiles)

Question 11

Order squamata includes what

Answer 11

Snakes and lizards

Question 12

Amphibia integument

Answer 12

• Thin, moist skin
• No scales except some caecilians
• Glands secrete moisture-maintaining substances
• Susceptible to desiccation
• Role in respiration
• Some = noxious/toxic compounds
• Cryptic, aposematic and mimicry colouration.

Question 13

Cryptic colouration

Answer 13

Camouflage

Question 14

Aposematic colouration

Answer 14

Colours indicating unpalatable prey

Question 15

Mimicry colouration

Answer 15

Harmless prey imitates appearance of dangerous one

Question 16

Reptile integument

Answer 16

• Thick, dry, covered in scales
• Scales formed by keratin in epidermis
• Undergo ecdysis
• Cryptic, aposematic and mimicry colouration

Question 17

Turtle integument

Answer 17

• Shell
• Upper section = Carapace, lower = plastron
• Scutes cover both
• Skin is shed but shell stays in place. Concentric rings show growth

Question 18

Frog locomotion and support

Answer 18

• As larvae: fusiform and laterally compressed tails for swimming
• Adults, many advances for life on land
• Skeletons substantial for support against gravity, flexible for locomotion
• Elongation of appendages, modification of vertebral column and pelvic girdles
• Fusion of many bones
• Skull is thin, light, and attached to neck

Question 19

Reptile locomotion and support

Answer 19

• Very variable
• More ossification of skeleton for greater support
• Extra cervical vertebrae for freedom of movement of head
• Some appendages tucked in
• Bipedalism (can use front limbs for things other than movement)
• All (including birds, excluding turtles) are diapsid skulls (2 openings) turtles lack the openings.

Question 20

Amphibian food acquisition and digestion (specifically anurans)

Answer 20

• larvae = herbivores
• all adults=carnivores mainly for invertebrates
• jaw allows them to crush prey held in mouths
• locate prey by sight and sit and wait strategy
• Specialized tongue hat folds back over floor of mouth. Flicks it out and entraps prey, flicks it back inside of mouth. Eyes sink down to force food down esophagus

Question 21

Reptile food acquisition and digestion

Answer 21

• Eat arthropods
• All, except some turtles, are carnivores
• Turtles have heavily keratinized beak and strong neck mscles instead of teeth
• Snakes jaws and skull bones are only loosely joined so can expand lots. Also venomous fangs

Question 22

Amphibian respiration

Answer 22

• Aquatic+larval=external gills that are reabsorbed in metamorphosis
• Adults= cutaneous. Can occur in water or on land if skin is moist
• Pulmonary resp = supplements cutaneous respiration
• Buccal pump generates positive pressure to ventilate lungs
• When weather is warm = pulmonary is most of respiration
• When temp is low, most is cutaneous.
• When hibernating in mud, gas exchange is exclusively cutaneous and blood flow to lungs is restricted

Question 23

Reptile respirationi

Answer 23

• pull air into lungs with negative pressure
• Turtles rely on muscular contractions, the rest use movement of ribs and body wall expansion
• Can restrict blood flow to lungs when pulmonary resp not possible (like turtles in shells or diving underwater)
• Some turtles can do bimodal breathing

Question 24

Circulation in tetrapods and lungfishes

Answer 24

• double circulation
  1. pulmonary system=blood through capillary bed of lungs to collect O2
  2. Systemic system=delivers blood to body

Question 25

Anurans circulation

Answer 25

- 2 atria and 1 ventricle, but very little mixing between O2 and no O2 blood - Cutaneous respiration and can restrict blood flowing through pulmonary circuit

Question 26

Reptile circulation

Answer 26

- 2 divided atria, 1 partially divided ventricle (fully divided in crocodilians) - partial opening means they can partially circumvent pulmonary circuit

Question 27

Amphibian excretion

Answer 27

- larvae + aquatic = ammonia - land = urea - mesonephric kidneys = large quantities of dilute urine when in water adn conserve ions - behaviour prevents water loss (foraging at night, returning to water during day)

Question 28

ammonia

Answer 28

energetically inexpensive but requires lots of water to excrete

Question 29

Urea

Answer 29

requires less water to excrete and can be stored in urinary bladder for a while

Question 30

Reptile excretion

Answer 30

- metanephric kidney = filter large quantities of blood and produce waste with little water loss - Uric acid (except turtles which do everything) - Integument is impermeable so no evaporative water loss

Question 31

Sensory abilities of amphibians

Answer 31

- Skin is sensitive - Larvae have lateral line system - Chemoreception (nasal epithelium, mouth, tongue and skin) - Olfaction = important for mate recognition, detection of noxious substances and prey capture - Sight important for prey location - Large optic lobes - Auditory system adapted for land (tympanic membrane, middle ear and inner ear), important for mate location

Question 32

Reptile sensory abilities

Answer 32

- Sight and smell are important so brain regions are big - Cerebellum is bigger due to better refined motor movement - Ears are varied, some rely on substrate vibrations - Sea turtles can sense earth's magnetic field

Question 33

Amphibian reproduction

Answer 33

- External fertilization (except salamanders and caecilians) - oviparous and ovoviviparity (some derived viviparity) - metamorphosis, - differing larval and adult forms reduces competition - some have parental care

Question 34

Reptile reproduction

Answer 34

- amniotic egg (completed transition to land) - oviparous - some extensive parental care like alligators

Question 35

Amniotic egg 4 parts

Answer 35

1. Amnion 2. Chorion 3. Allantois 4. Yolk

Question 36

Amnion

Answer 36

Filled with fluids, surrounds embryo. Protection from desiccation and shock

Question 37

Chorion

Answer 37

highly vascularized membrane for efficient gas exchange

Question 38

Allantois

Answer 38

Stores waste products from embryo

Question 39

Yolk

Answer 39

nourishes embryo throughout development

Question 40

Frog skeletal adaptations for jumping

Answer 40

Compressed vertebral column Urostyle (fused vertebrae at base of vertebral column) Radioulna Tibiofibula Elongated proximal tarsal bones (calcanium and talus)