CLASS REPTILIA - REPTILES
Diverse group of animals that are cold blooded. Turtles, snakes, lizards, crocodiles, alligators, tuatara. They breathe using lungs. Wide range of habitats. All reptiles are characterized by scales.
AMNIOTIC EGG - ITS IMPORTANT!
Retiles bear their young in eggs protected by an amniotic membrane. Amniotic eggs have a hard shell that protects the embryo. The egg is therefore better protected from predators. Amniotic fluid is present in all of the other classes of Chrodata that have hey to be studied here (humans and birds, for example).
SCALES TOO!
Scales define a reptile and they come in a variety of shapes, colors, and sizes. Scales are made of keratin and formed from the epidermis. They can be ossified or tubular, as in lizards, or modified elaborately,as in snakes. Scales are used for protection. They prevent the evaporation of moisture; so, they (like limbs) allow reptiles to live on land.
REPRODUCTION
Internal sexual reproduction; then, the egg is laid. Most reptiles, which lay eggs, are called oviparous (turtles, crocodiles, tuatara). Some reptiles, such as snakes and lizards, bear live offspring.
CIRCULATORY SYSTEM
Retiles have a closed circulatory system. Most reptiles have a 3 chambered heart (except crocodiles; have 4 chambers). Two separate atria, but also one ventricle that is partially divided by an incomplete septum. Yet, in crocodiles, the septum's division is complete=two separate ventricles, which keeps oxygen-rish blood separate from oxygen-poor blood throughout the heart. Not the case with all reptiles, though.
ECTOTHERMIC
Reptiles are ectothermic or "cold blooded." So, they cannot generate their own body heat.
AMNIOTIC EGG - ITS IMPORTANT!
Retiles bear their young in eggs protected by an amniotic membrane. Amniotic eggs have a hard shell that protects the embryo. The egg is therefore better protected from predators. Amniotic fluid is present in all of the other classes of Chrodata that have hey to be studied here (humans and birds, for example).
SCALES TOO!
Scales define a reptile and they come in a variety of shapes, colors, and sizes. Scales are made of keratin and formed from the epidermis. They can be ossified or tubular, as in lizards, or modified elaborately,as in snakes. Scales are used for protection. They prevent the evaporation of moisture; so, they (like limbs) allow reptiles to live on land.
REPRODUCTION
Internal sexual reproduction; then, the egg is laid. Most reptiles, which lay eggs, are called oviparous (turtles, crocodiles, tuatara). Some reptiles, such as snakes and lizards, bear live offspring.
CIRCULATORY SYSTEM
Retiles have a closed circulatory system. Most reptiles have a 3 chambered heart (except crocodiles; have 4 chambers). Two separate atria, but also one ventricle that is partially divided by an incomplete septum. Yet, in crocodiles, the septum's division is complete=two separate ventricles, which keeps oxygen-rish blood separate from oxygen-poor blood throughout the heart. Not the case with all reptiles, though.
ECTOTHERMIC
Reptiles are ectothermic or "cold blooded." So, they cannot generate their own body heat.