# data[].attributes.body
Chondricthyes: Sharks, Rays
Flexible endoskeletons made of cartilage. Cartilage is derived from boney ancestors.
They have well-developed haws and paired fins.
Two major groups are sharks and rays.
Sharks
sharp vision, can't distinguish colors.
strong smell (Olfaction).
Lateral line system to sense water vibrations.
Can sense electrical fields.Eggs are fetilized inside the shark, with all 3 gestation types.
lOviparous: eggs laid outside of mother in thick mucus layer

lOvoviviparous: retention of the eggs within the uterus but only the eggs nourishes the embryo.

lViviparous: placental formation in the uterus.
Rays
much larger pectoral fins
Many species have a venomous barb on the end of their tail used to avoid predation.

# data[].attributes.body
Osteoicthyes
Their endoskeletons are ossified (calcium phosphate).
they have flat boney scales.
lateral line system
gills are covered by a protective flap (operculum)
oviparous reproduction.
Three main groups are ray finned fish, lobe finned fish, and lung fish.
Ray finned fish
their spines protrude into the fin for support.
lobe finned fish
Have fins that are supported by skeletal extensions
lung fish
Have the ability to gulp air into lung sacs connected to the digestive system but mainly use gills for gas exchange.

# data[].attributes.attachment_link.description
Osteichthyes /ˌɒstiːˈɪkθi.iːz/, popularly referred to as the bony fish, is a diverse taxonomic group of fish that have skeletons primarily composed of bone tissue, as opposed to cartilage.The vast majority of fish are members of Osteichthyes, which is an extremely diverse and abundant group consisting of 45 orders, and over 435 families and 28,000 species.It is the largest class of vertebrates in existence today.The group Osteichthyes is divided into the ray-finned fish and lobe-finned fish .

# data[].attributes.body
Reptilia
They have keritin scales which waterproof their skin.
They get all of their oxygen through their lungs.
They lay shelled amniotic eggs.
Ectothermic, they use behavior to regulate their body temperature.
Three major groups are testudines, squamata, and crocodilia.
Testudines are turtles
turtles have a hard dorsal shell that acts as armor, some can hide their head inside this shell. some are marine, some are terrestrial.
Squamata are lizards and snakes.
They have scales, as well as move-able upper jaws.
Crocodilia are crocodiles and alligators.
semiaquatic, large predatory animal. Four chambered heart.

# data[].attributes.attachment_link.keywords[]
visit www.oztern.com to find personalized test preparation solutions for pre medical - aipmt

# data[].attributes.attachment_link.description
Useful for CBSE, ICSE, NCERT & International Students Grade 09 Subject: Biology Lesson : DIVERSITY IN LIVING WORLD Topic: CLASS REPTILIA These animals are cold-blooded, have scales and breathe through lungs. While most of them have a three-chambered heart, crocodiles have four heart chambers.

# data[].attributes.body
Mammalia
Milk production

They have hair made of keratin

They are endothermic.

They give live birth.

Viviparous

They generally have larger craniums so more and complex behaviors.
Four orders include carnivora, pinnipedia, sirenia, and cetaceans.
carnivora are bears and otters.
they are carnivorous, with sharp canine teeth and molars for sheering. Sea otters lack blubber, but has dense fur which traps air for insulation, hunted for pelt. Sea otters are dope af.
pinnipeida are sea lions, seals, and walruses. Walruses are strictly arctic, with tusks for defense and anchoring in ice. They are benthic feeders.
Sirenia are manatee and dugong. front flippers but no rear limbs. close to elephant.
cetaceans are dolphins, whales, and porpoises.
streamlined bodies, no hind limbs, paddle-like forelimbs (flipper?), thick blubber.

# data[].attributes.attachment_link.title
Evolution of cetaceans - Video Learning - WizScience.com

# data[].attributes.attachment_link.description
The cetaceans are marine mammal descendants of land mammals. Their terrestrial origins are indicated by: The question of how a group of land mammals became adapted to aquatic life was a mystery until discoveries starting in the late 1970s in Pakistan revealed several stages in the transition of cetaceans from land to sea.

# data[].attributes.body
Aves
Their primary characteristics revolves around the evolution to flight.
Lack teeth and use a gizzard to grind food.
Forelimbs to function as wings.
Some lack organs (having one ovary).
Their bones are hollow to decrease the weight.
They have feathers made of keratin.
They are endothermic for increased metabolism.
They have a four chambered heart for efficient blood circulation.
One way respiratory system.
they have a large keel to anchor pectoral muscles.