Zoology Final b

Question 1

types of reptiles

Answer 1

• snakes

- turtles

Question 2

What made possible the complete conquest to land?

Answer 2

development of an amniotic egg that can be laid away from water - finally severed the ties to aquatic reproduction

Question 3

characteristics of amniotic egg

Answer 3

• eggshell enclosing series of membranes which include: amnion, allantois, yolk sac, chorion and chorioallantoic

Question 4

amnion

Answer 4

acts as a “shock absorber” to protect fetus

- creates aquatic environment

Question 5

allantois

Answer 5

• vascularized
• contains blood vessels
• used for gas exchange and storage of nitrogenous waste

Question 6

yolk sac

Answer 6

contains food for the embryo

Question 7

chorion

Answer 7

enclose the other membranes

Question 8

chorioallantoic

Answer 8

• the membrane of fused chorion and allantois

- membrane functions in gas exchange through porous eggshell

Question 9

amniotes

Answer 9

• monophyletic group of tetrapods that have amniotic egg

- include: reptiles, birds and mammals

Question 10

extant reptiles

Answer 10

• crocodilians
• lizards
• snakes
• turtles
• tuataras

Question 11

extinct reptiles

Answer 11

• dinosaurs
• mesosaurs
• plesiosaurs
• pterosaurs

Question 12

reptilian skin

Answer 12

have tough, dry clay skin which offers protection against desiccation and physical injury
- waterproof

Question 13

reptile scales

Answer 13

• reptilian scales are derived from epidermis of skin and formed largely of keratin
• not homologous to fish scales, which are bony, dermal structures
• homologous to scales on legs of birds, and the farther of birds which develop from scale-like structures

Question 14

reptile jaws

Answer 14

• designed for quick closure but cannot exert much force once prey is captured
• efficiently designed for applying crushing or gripping force to prey

Question 15

snake and lizard jaw

Answer 15

• kinetic skull with moveable quadrate bone
• enables upper jaw to be raised independently thus increasing the effective closing force of jaw musculature
• enables them to “unhinge” jaw
• considered major factor in diversification and ecological success of these animals

Question 16

reproduction in reptiles

Answer 16

• have internal fertilization necessitating some form of copulatory organ
• internal fertilization is necessary so that egg is fertilized before the eggshell is added

Question 17

circulatory system in reptiles

Answer 17

• have higher blood pressure and in general is more efficient
• have incompletely 4-chambered heart (not fully formed septum)

Question 18

respiratory system in reptiles

Answer 18

• lungs are better developed, no need for cutaneous respiration through skin
• air sucked into lungs rather than pushed
• no true diaphragm
• create negative pressure by expanding rib cage when they breathe

Question 19

reptilian advances

Answer 19

• more efficient kidney for water conservation, enabling them to live in dry environments
• considerably more advanced nervous system with first true cerebral cortex - more complex behavior

Question 20

ancient reptiles

Answer 20

• turtles
• virtually unchanged during 200 million years of evolutionary history
• shell formed from ribs and vertebrae - inner bony layer and out keratin

Question 21

life history of turtles

Answer 21

• apparently can live more than 150 years due to relatively low metabolism
• may secede 1598 pounds
• very few sea turtles reach extreme size because they are heavily exploited
• many endangered or threatened

Question 22

sense in turtles

Answer 22

• hearing, virtually silent except during mating
• good sense of smell
• excellent eyes color perception is as good as it is in humans, allowing them to catch prey quickly and accurately

Question 23

difference between turtle, tortoise and terrapin

Answer 23

• turtle > webbed-feet
• tortoise > stumped feet
• terrapin > mixture of webbed-feet and stumped feet

Question 24

characteristics of snakes

Answer 24

• possess heat-sensitive pit organs that are so sensitive they can detect prey in total darkness, up to .003 degree change
• special muscles erect hollow fangs when they bite
• venom gland produces venom

Question 25

senses of snakes

Answer 25

- tongue picks up scent, then drawn across Jacobson's organ in roof of mouth which does the actual smelling - have internal ear bones - can sense vibrations but may not be actually able to hear

Question 26

characteristics of lizards

Answer 26

- very diverse - 5000 species - extremely keen eyesight - can see some UV light

Question 27

sex determination in komodo dragons

Answer 27

- ZW sex determining system, males are ZZ - ovum determines the sex - capable of parthenogenesis if no males are around - females lay unfertilized eggs and the Z chromosome just doubles > so no fertilization

Question 28

characteristics of tutara

Answer 28

- endemic to New Zealand - most recent common ancestor is lizards and snakes - up to 30 in. long, spiny crest along back - living fossils

Question 29

characteristics of crocodilians

Answer 29

- mostly unchanged for 200 million years - 4-chambered heart - devoted parents that care for young after hatching - mother responds to vocalizations of hatchlings and helps them break out of nest, then carries them to safety - crocodile is endangered - alligator is threatened

Question 30

sex determination in crocodilians

Answer 30

- temperature of the nest determines the sex - male > 88 degrees - female < 88 degrees

Question 31

difference between alligator and crocodile

Answer 31

- alligators are mainly freshwater and have a rounded nose | - crocodiles are both freshwater and seawater and have a more pointed nose

Question 32

reptile survival

Answer 32

- severe decline due to habitat loss and poaching | - many endangered and threatened species

Question 33

two major groups of dinosaurs

Answer 33

- saurischians - ornithischians - dominated earth - differ in way the pelvis sits

Question 34

saurischians

Answer 34

lizard-hipped

Question 35

ornithischians

Answer 35

bird-hipped