Biology Questions and Answers
- How can the tubular-dorsal
nervous system in chordates
be compared to the nervous
pattern present in
invertebrates?
In chordates the nervous system isdorsal and highly cephalized while in (^)
most invertebrates the nervous system
is ganglial and ventral.
- What is the group of the
phylum Chordata that first
colonized the terrestrial
environment? From which
habitat did they come?
Amphibians, pterrestrial animals,artially were the first aquatic partially
chordates that coloThey came from the aquatic habitat andnized the dry land. (^)
were originated from fishes.
(Nevertheless the first completelyterrestrial chordates were the reptiles).
- How do chordates
reproduce?
Reproduction in beings of the phylum
Chordata is sexual, with thof urochordates that can also re exceptioneproduce (^)
asexually. In some classes
(cyclostomes,amphibians) there is larval osteichthyes fish stage. Wites andh (^)
rare exceptions, fishes, amphibians,
reptiles anoviparous, ed monotremgg-laying (embryos de mammals areevelop (^)
within eggs and outside the mother’s
body) and marsumammals are viviparous (pial and placentalembryos (^)
develop inside the mother’s body,
feeding from her).
- Into which subphyla are the
protochordates divided? What
are some representatives of
each protochordate
subphylum?
Urochordates (or cephalochordates artunicates) ane the two sud (^) bphyla
into which protochordates are divided.
Ascidians, sessile animals similar to
sponges, aramphioxus, we examell-studieples of tunicates. Td in Embryology,he
is an example of cephalochordate.
- What are the six criteria
used to build a complete
evolutionary branch of
vertebrates?
Dichotomy in each of the six followingcriteria builds the vertebrate
evolutionary mandibles separates cyclostomes frbranch: absence of (^) om
others; absence of limbs separates
fishes from the remaiosseous skeleton separatesning; absence of
chondrichthian (cartilaginous) from osteichthyes; absence of fishes
impermeable skin separates amphibians
from thabsence e terrestrial vertebrates;of warm blood (homeothermic (^)
body) separates reptiles from birds and
mammals; absand hair separatesence o birds fromf mammary glands
mammals.
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