2. BIRDS
Birds (class Aves) are
feathered, winged,
bipedal, endothermic (
warm-blooded),
egg-laying, vertebrate
animals. With around
10,000 living species,
they are the most
speciose class of
tetrapod vertebrates.
3. The flight
Most birds can fly, which
distinguishes them from almost
all other vertebrate classes.
Flight is the primary means of
locomotion for most bird
species and is used for
breeding, feeding, and
predator avoidance and escape.
4. Curiosity
Chromosomes
Birds have two sexes: male
and female. The sex of
birds is determined by the
Z and W sex chromosomes,
rather than by the X and Y
chromosomes present in
mammals. Male birds have
two Z chromosomes (ZZ),
and female birds have a W
chromosome and a Z
chromosome (WZ).
5. Reptiles
Reptiles (Reptilia) are
members of a class of air-
breathing, ectothermic (cold-
blooded) vertebrates which
are characterized by skin
covered in scales and/or
scutes
6. Metabolism
All reptiles exhibit some
form of cold-bloodedness so
that they have limited
physiological means of
keeping the body
temperature constant and
often rely on external
sources of heat.
7. Orders
The modern
reptiles are divided
in 3 big orders:
lorica, such as
crocodiles, turtles
and scaled such as
lizards. They are all
ectotermic and
tetrapods.
