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Flashcards in Zoology Final b Deck (35):
1

types of reptiles

- snakes
- turtles

2

What made possible the complete conquest to land?

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

3

characteristics of amniotic egg

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

4

amnion

acts as a "shock absorber" to protect fetus
- creates aquatic environment

5

allantois

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

6

yolk sac

contains food for the embryo

7

chorion

enclose the other membranes

8

chorioallantoic

- the membrane of fused chorion and allantois
- membrane functions in gas exchange through porous eggshell

9

amniotes

- monophyletic group of tetrapods that have amniotic egg
- include: reptiles, birds and mammals

10

extant reptiles

- crocodilians
- lizards
- snakes
- turtles
- tuataras

11

extinct reptiles

- dinosaurs
- mesosaurs
- plesiosaurs
- pterosaurs

12

reptilian skin

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

13

reptile scales

- 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

14

reptile jaws

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

15

snake and lizard jaw

- 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

16

reproduction in reptiles

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

17

circulatory system in reptiles

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

18

respiratory system in reptiles

- 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

19

reptilian advances

- 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

20

ancient reptiles

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

21

life history of turtles

- 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

22

sense in turtles

- 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

23

difference between turtle, tortoise and terrapin

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

24

characteristics of snakes

- 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

25

senses of snakes

- 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

26

characteristics of lizards

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

27

sex determination in komodo dragons

- 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

28

characteristics of tutara

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

29

characteristics of crocodilians

- 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

30

sex determination in crocodilians

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

31

difference between alligator and crocodile

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

32

reptile survival

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

33

two major groups of dinosaurs

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

34

saurischians

lizard-hipped

35

ornithischians

bird-hipped