Chapter 31 (1&2) and 32 (1&2) notes May 10th QUIZ!! Chapter 31 (1&2) and 32 (1&2) notes Computer room tomorrow! Rm 3201 Sub 5th, 6th and 7th HW- Chapter 32 notes 1 & 2

Reptiles – Class Reptilia A reptile is a vertebrate that has dry, scaly skin, lungs, and terrestrial eggs with several membranes

Form and Function in Reptiles Most reptiles have adapted to a fully terrestrial life: tough, scaly skin well developed lungs a double-loop circulatory system a water-conserving excretory system – kidney’s strong limbs internal fertilization shelled, terrestrial eggs control of body temperature by changing their environment (?)

Body Temperature Control in Reptiles Reptiles are ectotherms They rely on behavior to help control body temperature To warm up, they bask in the sun To cool down, they move to the shade/water

Reptile Feeding & Respiration Reptiles range from herbivores to carnivores The lungs of reptiles are spongy, providing more gas exchange area than those of amphibians Most reptiles have 2 efficient lungs to exchange gas with the environment

Reptile Circulation & Excretion Reptiles have an efficient double-loop circulatory system Their heart contains two atria and either one or two ventricles Urine is produced in the kidneys of reptiles By eliminating wastes that contain little water, a reptile can conserve water

Reptile Response The basic pattern of a reptile’s brain is similar to that of an amphibian In addition to a pair of nostrils, most reptiles have a pair of sensory organs in the roof of the mouth that can detect chemicals Reptiles have simple ears and can pick up on ground vibrations and body heat

Reptile Reproduction All reptiles reproduce by internal fertilization Most reptiles are oviparous (lay eggs that develop outside the mother’s body) Reptilian eggs are amniotic They contain a shell and membranes that create a protected environment in which the embryo can develop without drying out

Evolution of Vertebrates

Birds – Class Aves Birds are reptile-like animals that maintain a constant internal body temperature They have an outer covering of feathers; two legs that are covered with scales; and front limbs modified into wings

Birds This single most important characteristic that separates birds from living reptiles, and from all other living animals, is feathers Feathers are made mostly of protein and develop from pits in the birds’ skin Feathers help birds fly and also help to keep them warm The 2 main types of feathers are contour feathers and down feathers

Form, Function, and Flight Birds have a number of adaptations that enable them to fly: Highly efficient digestive, respiratory, and circulatory systems Aerodynamic feathers and wings Strong chest muscles

Form, Function, and Flight

Body Temperature and Control in Birds Birds are endotherms (animals that can generate their own body heat) They have a high rate of metabolism compared to ectotherms (metabolism produces heat) A bird’s feathers insulate its body enough to conserve most of its metabolic energy

Bird Feeding The more food a bird eats, the more heat energy its metabolism can generate A bird’s beak, or bill, is adapted to the type of food they eat

Bird Digestion esophagus  crop  stomach  gizzard  small intestines large intestines cloaca

Bird Respiration When a bird inhales, most air first enters large posterior air sacs in the body cavity and bones The inhaled air then flows through the lungs in a series of small tubes air flows in a single direction This constant, one way flow of oxygen-rich air helps birds maintain their high metabolic rate and generates enough energy for flight

Circulation, Excretion, and Response in Birds 4 chambered hearts and two separate circulatory loops Excretion Similar to those of reptiles – white, pasty uric acid droppings Response Well developed sense organs Well developed eyes that can see color Excellent hearing

Reproduction in Birds Bird eggs are amniotic eggs They have hard outer shells Most birds incubate their eggs until they hatch

Characteristics of Mammals Meaning – mamma = breast Have hair Provides insulation and water proofing Endotherms (warm blooded) Feed young w/ milk from mammary glands Respiratory system includes: diaphragm and lungs

Characteristics of Mammals Teeth modified according to type of food eaten Chisel-shaped for gnawing (beaver) Canines for tearing and puncturing (lion) Premolar & molars for slicing, shearing, crushing and grinding (humans) Modified limbs Opposable thumb to grasp objects Wings to fly (bats) Claws to climb Ability to learn

Characteristics of Mammals Complex nervous system and senses Have sweat, oil and scent glands 4 chambered heart

Classified by how they reproduce 3 sub-classes 1. Monotremes Mammals that reproduce by laying eggs Found only in Australia, Tasmania, and New Guinea Duck-billed platypus and spiny ant-eater

2. Marsupials Young have a short period of development within the mother’s body followed by a second period of development inside a pouch made of skin and hair outside the mother’s body Kangaroos, opossum, spotted cuscus, and giant anteater Most found in Australia

3. Placental mammals Carry young inside of uterus until development is nearly complete Young are nourished via placenta Time inside the placenta is known as gestation 95% of all mammals Humans (9 months), elephants (22 months), dogs (9 weeks), bison (~9 ½ months), lions (~4 months), and dolphins (12 months)