2. Presence of pharyngeal slits
which are openings between the
throat and the outside. It performs
various function such as to filter
food particles and gaseous
exchange.
Presence of post-anal tail, an
extension of the notochord that
extends beyond the anus.
4. - These are the chordates
whose notochord remain during
the entire life of the organisms.
There are two distinct groups:
cephalochordate and tunicata
5. -it is represented by the lancelet
or amphioxus, a chordate with a
fishlike appearance. It lacks
bones and brains, but with a
notochord and a nerve cord just
above it.
6.
7. - an unusual chordate that lives
attached to the seabed. The
swimming larva of the organism
contains the notochord, and all
the rest of the distinguishing
features of chordates.
8.
9. - are the chordates that have
notochord and pharyngeal slits
during the early stages of
development. As the animals
mature, rings of bones called
vertebrae replace the notochord.
The vertebrate chordates are
divided into seven classes.
10. Class Agnatha (a- = not, without;
gnathos = jaw). This is represented
by the lamprey, an eel-shaped
jawless fish that is considered as
the vampire of the ocean
because it preys on other fish by
sucking their blood.
11.
12. -( chondro = cartilage; ichthyes =
fish). The fish with cartilaginous
endoskeleton. Sharks and sting
rays represent this class.
13.
14. -(osteon = bone; ichthyes = fish )
The class of the bony fishes. This
group consist of many members.
Milkfish
15. - (amphios = on both sides,
double; bios = life). Named
because in their life cycle, the
larval part of the life of the
amphibians is spent in water and
the adult part is spent on land.
They are the first land vertebrates
to emerge.
19. - (aves = birds). Aves have bodies
covered with feathers, scaly feet
that are adapted to the kind of
environment they live, wings that
are adapted for flight, and the
beaks that are adapted to the kind
of food they eat.
20.
21. - (mamma = breasts). The presence
of breasts is a distinguishing feature of
mammals. Another distinguishing
feature of mammals is that their bodies
are covered with hair. Almost all
mammals are vivaparous.
Mammals are divided into three
subclasses: monotremata, marsupialia
and placetals
22. - (trema = hole). Monotremes
have bodies covered with thick
furs. They have breast that lack
nipples, but secrete milk. These
mammals are unique as they are
the only egg-laying (ovaparous)
mammals. Their young lick the
milk that oozes in their thick fur.
24. - (marsupium = bag or pouch).
Described as pouched mammals.
The marsupium contains the
nipples that secrete milk.
Kangaroo, koala and opossums
represents this group.
26. - Placenta pertains to a part in
the womb where the young is
nourished as it undergoes
development until birth. This
group comprises the largest and
the most diverse forms of
chordates. Placental mammals
are divided into different orders.
