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

• Circulation– 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)