ANIMAL TRAITS

Question 2

Main characteristics of phylum chordata

Answer 2

• dueterostome
• notochrod (rod-like body in embryo)
• hollow dorsal nerve cord
• pharyngeal slits
• muscular tail past anus (during embryo)
• bilateral symmetry
• segmentation (similar structures e.g ribs)

Question 3

characterisitcs of fish

Answer 3

• gills (evolved from pharyngeal slits)
• ectothermic
• aquatic
• fins
  -scales
• two-chambered heart
• have jaws or don’t have jaws (hagfish)

Question 4

defining features of vertebrates

Answer 4

• vertebrae and spinal cord
• elaborate skull
• fin rays

Question 5

features of jawless fish

Answer 5

• cartilaginous segments surrounding noto-chord
• simple hears
• hermaphroditic (sometimes)

Question 6

two classes of fish

Answer 6

cartilagenous (chondrichthyes)
- cartilage skeleton
- no swim bladder
- 2 chamber heart
bony fish (osteichthyes)
- bone skeleton
- swim bladder
- simple systems

Question 7

oviparous
oviviparous
viviparous

Answer 7

oviparous = eggs hatch outside mother
oviviparous = embryo develop in uterus and nourished in egg yolk
viviparous = embry develop in uterus, nourished throughplacenta yolk through mothers blood

Question 8

Amphibia characteristics

Answer 8

• both terrestrial and aquatic
• moist skin for gas exchange
• fertilisation is external
• 3 chambered heart
• larvae undergo hormonal changes and physical effects to mature

Question 9

what are amniotes

Answer 9

tetrapods with amniotic egg adapted to terrestrial = contains membranes to protect embryo
- amnion, chorion, yolk, allantois

• also impermeable skin
• ability to ventilate lungs

Question 10

characterisitics of reptilia

Answer 10

• scales - waterproof
• lay shelled eggs
• terrestrial (mostly)
• ectotherms
• only one functioning lung
• no diaphragm
• 3 chambered heart (septum)

Question 11

characterisitcs of birds (Aves)

Answer 11

• bipedal
• warm-blooded/endotherm
• feathers = keratin
• forelimbs = wings
• hollow bones*
• one ovary
• no teeth
• 4 chambered heart
• air sacs
• crop and gizzard + proventriculus
• renal portal system -> large lidneys (uric acid)

Question 12

characterisitcs of mammals

Answer 12

endotherm
- differentiated teeth
- mammary glands (nourish young)
- live young
- hair/fur
- evolved from synapsid reptiles -> created ear ossicles
- skeleton
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