Tetrapods

Question 1

What group are amphibians and reptiles part of?

Answer 1

They are both part of the Tetrapoda, four-limbed vertebrates that evolved from lobe-finned fish.

Question 2

What was a major evolutionary step enabling tetrapod life on land?

Answer 2

Development of lungs and limbs capable of bearing weight.

Question 3

What are key features of amphibians?

Answer 3

Moist skin, cutaneous respiration, metamorphosis, external fertilisation, mostly aquatic eggs.

Question 4

What are the three major orders of amphibians?

Answer 4

Anura (frogs & toads), Caudata (salamanders), Gymnophiona (caecilians).

Question 5

What limits amphibians’ terrestriality?

Answer 5

Their reliance on moist environments for respiration and reproduction.

Question 6

What are the respiratory strategies of amphibians?

Answer 6

Lungs, gills (larvae), and skin (cutaneous respiration).

Question 7

Why do amphibians use external fertilisation?

Answer 7

Because they lay eggs in water, sperm must be released directly onto eggs.

Question 8

What are caecilians and how are they adapted to their lifestyle?

Answer 8

Limbless, burrowing amphibians with sensory tentacles and internal fertilisation.

Question 9

What is an amniotic egg and why is it important?

Answer 9

An egg with membranes (amnion, chorion, allantois) allowing reproduction away from water.

Question 10

What are the main adaptations of reptiles to terrestrial life?

Answer 10

Dry, scaly skin, internal fertilisation, amniotic eggs, more efficient lungs.

Question 11

What is Carrier’s Constraint and how does it affect reptiles?

Answer 11

The inability to run and breathe simultaneously due to lateral body bending during locomotion.

Question 12

How do reptiles overcome Carrier’s Contstraint?

Answer 12

By using gular (throat) pumping, erect posture (in some lineages), and other modifications.

Question 13

What are the major reptile groups (extant)?

Answer 13

Crocodilia, Testudines (turtles), Lepidosauria (lizards, snakes, tuataras).

Question 14

What are lepidosaurs?

Answer 14

The clade containing lizards, snakes, and tuataras; they have overlapping scales and shed skin.

Question 15

What unique features do snakes have?

Answer 15

Limbless bodies, kinetic skulls for consuming large prey, Jacobson’s organ for chemoreception.

Question 16

What adaptations do turtles have?

Answer 16

A bony or cartilaginous shell fused to the ribs, no teeth (keratinised beak), and internal lungs.

Question 17

What distinguishes crocodilians?

Answer 17

Semi-aquatic, four-chambered hearts, parental care, vocalisation, and ambush predation

Question 18

Why are amphibians sensitive environmental indicators?

Answer 18

Their permeable skin and dual life cycle make them vulnerable to changes in air and water quality.

Question 19

What are the three main orders of Amphibia?

Answer 19

Anura (frogs and toads), Caudata (salamanders and newts), Gymnophiona (caecilians)

Question 20

What are key characteristics of Anura?

Answer 20

No tail in adults, powerful hind limbs for jumping, vocal sacs in males, external fertilisation, aquatic larvae (tadpoles)

Question 21

How do frogs differ from toads?

Answer 21

Frogs typically have smooth, moist skin and are more aquatic; toads have dry, warty skin and are more terrestrial

Question 22

What distinguishes Caudata?

Answer 22

Elongated bodies, tails in both larvae and adults, internal fertilisation in many, cutaneous respiration is common

Question 23

What is paedomorphosis and how does it relate to salamanders?

Answer 23

The retention of juvenile features in the adult stage — seen in species like the axolotl, which retains gills

Question 24

What are caecilians and their features?

Answer 24

Limbless, burrowing amphibians with sensory tentacles, reduced eyes, internal fertilisation, and some show parental care

Question 25

How do caecilians reproduce?

Answer 25

Most are viviparous (live birth), and some lay eggs and guard them. Fertilisation is internal via a phallodeum (male copulatory organ)

Question 26

What are the four major extant reptilian groups?

Answer 26

Testudines (turtles and tortoises), Lepidosauria (lizards, snakes, tuataras), Crocodilia (crocodiles, alligators), and Aves (birds – traditionally considered separately, but now known to be reptiles)

Question 27

What distinguishes Testudines?

Answer 27

Bony or cartilaginous shell, no teeth (have a beak), vertebrae and ribs fused to shell, internal fertilisation, long lifespans

Question 28

How do aquatic and terrestrial turtles differ?

Answer 28

Aquatic turtles have webbed feet or flippers, streamlined shells; tortoises are more domed and have sturdy, column-like legs

Question 29

What traits unite Lepidosaurs?

Answer 29

Overlapping scales, transverse cloacal slit, ability to shed skin in large pieces.

Question 30

What is unique about tuataras?

Answer 30

Only two living species, endemic to New Zealand, retain primitive features, slow metabolism, and a "third eye" (pineal organ)

Question 31

What adaptations do lizards have?

Answer 31

Movable eyelids (in most), external ear openings, tail autotomy (can shed tail), and diverse diet and habitats.

Question 32

What are key features of snakes?

Answer 32

No limbs, no eyelids, no external ears, forked tongue, kinetic skulls, many use Jacobson's organ for chemoreception.

Question 33

What are crocodilians known for?

Answer 33

Four-chambered heart, powerful jaws, parental care, vocalisations, semi-aquatic ambush predators.

Question 34

What’s the difference between crocodiles and alligators?

Answer 34

Crocodiles have V-shaped snouts, are more aggressive, and have exposed upper and lower teeth; alligators have U-shaped snouts and upper teeth are hidden when mouth is closed