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Reptiles and BirdsBy: Andrea Gamber, Shelly Nolt, and

Kaitlyn DeFernelmont, period 1

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Reptiles : Scaly-skinned vertebrates that breathe with lungs and lay eggs that hatch on land

+Reptiles Body Plan

Contrary to common belief, reptile scales can be smooth or rough, and they are never slimy.

The basic reptilian body plan includes a well developed skull, a backbone and tail, two limb girdles, and four limbs.

The only two reptiles that do not follow this plan are turtles (which have a hard shell fused to their vertebrae) and snakes (which have no limbs).

Reptiles are “heated from the outside.” Because of this, they are called ectotherms and they lack effective insulation so they need to gain additional heat by laying in the sun.

Skeletal

+Feeding

Some reptiles are herbivores while others are carnivores.

The way reptiles get their prey vary. Some snakes paralyze with a powerful venom while others suffocate their prey by wrapping tightly around them.

+Respiration and Internal Transport Since gasses are unable to diffuse easily across the scaly

skin of reptiles, all reptiles have well-developed lungs, to help in this area.

To help with this area also, reptiles have muscles attached to their rib cage to enable their lungs to inflate and deflate. Diagram

Additionally, reptiles have a double-loop circulatory system to allow the blood to first pass through the lungs and then to the remainder of the body. Diagram

Although there are exceptions, most reptiles have a “not quite four-chambered heart because the oxygenated and deoxygenated blood mix in a few areas.

+Excretion

Reptiles that live primarily in the water (like alligators and crocodiles) excrete most of their nitrogenous wastes in the form of ammonia.

Many other reptiles covert their waste into uric acid.

The excretion of uric acid presents two benefits over ammonia: 1. Uric acid is less toxic. 2. It is not soluble in water.

As a result, reptiles with uric acid excretion are better able to conserve water because the urine flows into an organ called the cloaca, where crystals of uric acid form a semisolid paste. By getting rid of these dry wastes, water is able to be conserved. Diagram

+Nervous System and Sense Organs

Reptiles have brains similar to Amphibians, except reptiles have a bigger cerebrum and cerebellum.

Reptiles have really good vision.

According to the Biology textbook, most snakes probably see more colors than you do!

+Movement

Reptiles have large and strong legs that easily support their body weight.

Their strong limbs allow for many actions to be performed, including running, swimming, burrowing, and climbing.

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•Reptiles are the first vertebrates to live without relying on water.•This is because their eggs are fertilized internally, and then develop into an amniotic egg meaning an embryo surrounded by a leathery external shell.•Reptiles that lay eggs lay them on loose earth or sand

Reproduction

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Birds :Any warmblooded vertebrae of the class Aves, having a body covered in feathers, forelimbs modified into wings, scaly legs, a beak and no teeth and bearing young in a hard-shelled egg

+The Bird Body Plan

The body of birds is much like that of reptiles because they supposedly are descendants of small dinosaurs, according to the Biology textbook.

However they are unlike reptiles, and every other type of animal, in that they have feathers.

Birds also have a high metabolism rate and are able to maintain a high body temperature as a result of their endothermic bodies which allow them to be heated from the inside.

Internal Bird Anatomy

+Beaks

The presence of a beak is another characteristic that quickly distinguishes the bird from any other organism.

While this is the case, it is interesting to note that each bird uses its beak to perform different tasks. For example: Toucans use their strong beak to slice fruit,

while pelicans use their long beak to catch fish. BEAKS

+Respiration and Internal Transport

Proper respiratory and circulatory systems are needed in order for birds to keep up enough energy to complete daily activities, such as flying. Circulatory Paths

To fly, birds are required to breathe at a steady rate, and therefore their lungs are much like the lungs of humans.

Additionally, the heart of birds is similar to humans in the four-chambered structure, and birds also have a double-loop circulatory system to carry food, oxygen, and wastes.

+Excretion

Very similar to that of reptiles.

The kidney removes nitergenous wastes from the blood and deposits them in the cloaca.

Water is then reabsorbed, leading to the formation of uric acid crystals.

Birds that live in marine habitats have specially developed salt glands.

+Nervous System and Sense Organs

Despite common thought, birds are actually quite intelligent.

Unlike the reptiles, their cerebrum and cerebellum are large and well developed.

Bird senses are very well developed as well.

Taste and smell are the only two senses that are not well developed in birds.

+Birds and Flight

Birds are able to fly because of their light bodies, powerful breast muscles, and aerodynamic feathers and wings.

+Works Cited

Turtle diagrams: http://www.bio.davidson.edu/Courses/anphys/2000/Pleasants/resp.htm http://www.bio.davidson.edu/Courses/anphys/2000/Pleasants/circ.htm

Bird diagrams: https://7salemanimalkingdom.wikispaces.com/file/view/InternalBirdAnatomy.JPG http://www.infovisual.info/02/060_en.html

All pictures are from clipart!