1. Chapter 31 Reptiles and Birds Mrs. Rushing Biology 2

2. Nonvertebrate chordates
Mammals
Birds
Reptiles
Amphibians
Fishes
Nonvertebrate chordates
Invertebrate ancestor

3. Reptiles Pgs

4. What Is a Reptile? Body plan typical to that of other land vertebrates
Well developed skull
Backbone
Tail
Two limb girdles
Four limbs

5. Characteristics of all Reptiles
Vertebrate
Dry, scaly skin where scales can be smooth or rough and most times shed
Lungs
Terrestrial eggs with several membranes
**Enable reptiles to live their entire lives out of water

6. Reptilian skin
Dry
Often covered with thick, protective scales
Smooth or rough
Protection
Helps prevent the loss of body water
***Dry waterproof skin has a disadvantage. Can you think of what this might be?

7. Body Temperature Control
Ectotherms –Animal that relies in interactions with the environment to help it control body temperature.
If they want to get warm they go into the sun and if they want to cool off they get out of the sun

8. Feeding Herbivores – Iguanas
Long digestive systems enable them to breakdown plant material.
Carnivores – snakes, crocs, and alligators
Grab prey with their strong jaws and swalow most meals whole.

9. Respiration
To exchange gases with the environment , reptiles have two efficient lungs or, in in the case of certain species of snake, one lung.
Lungs are more spongy than amphibians for better exchange gases – reptiles can NOT exchange gases through skin

10. Circulation Closed, double loop heart system
Loop one- brings blood to and from the lung
Loop two- brings blood to and from the rest of the body
2 atria and either 1 or 2 ventricles
Most reptiles don’t have a completed septum
Crocs and gators have most developed hearts of living reptiles (much like a mammal heart)

11. The Structure of a Turtle’s Heart
Section 31-1
Kidney
Liver
Heart
Cloaca
Lung
Bladder
Digestive tract
To body
Right atrium
From lungs
To lungs
Left atrium
From body
Ventricle
Incomplete division

12. Excretion Urine either contains ammonia or uric acid
If mostly a water animal - ammonia (which is toxic) is excreted because it can be diluted
If mostly a land animal – uric acid is excreted (a white paste because water is absorbed in cloaca)
****By eliminating wastes that contain little water, a reptile can conserve water.

13. Response
Active during the day and have complex eyes and see color very well
Many snakes have a very good sense of smell and some can detect heat and ground vibrations through bones in their skulls
Nostrils and sensory organs on roof of mouth that can detect chemicals
Simple ears with external eardrums and a single bone that conducts sound to the inner ear.

14. Movement
Reptiles have legs with larger stronger limbs enabling them to: walk, run, burrow, swim, or climb
May have rotated legs under the body to carry more weight
Backbones of reptiles help accomplish most of their movement

15. Reproduction
Internal fertilization in which male deposits sperm inside the female’s cloaca
Most male reptiles have a penis
After fertilization, the female’s reproductive system covers the embryo with several membranes and a leathery shell
Most reptiles are oviparous, laying eggs that develop outside the mother’s body.
By carrying her eggs within her body, eggs are protected and kept warm.

16. Amniotic egg Most important adaptation to life on land
Four membranes surround the developing embryo:
1. amnion
2. yolk sac
3. chorion
4. allantois

17. The Amniotic Egg Section 31-1 -- -Amnion Embryo Allantois-
The chorion regulates
the transport of
oxygen from the
surface of the egg
to the embryo and
carbon dioxide,
one product of
respiration, in the
opposite direction.
This baglike structure
contains a yolk that
serves as a nutrient-rich
food supply for the embryo.
The amnion is a fluid-filled sac
that surrounds and cushions
the developing embryo. It
produces a protected, watery
environment. --
The allantois stores the
waste produced by the
embryo. It also serves
as a respiratory organ.
Chorion
Yolk sac-
Shell

18. Groups of Reptiles 1) Lizards and snakes ( Order Squamata)
2) Crocodilians – crocs, gators, caimans, and gavials (Order Crocodilia) Alligators live in fresh water while crocodiles live in fresh or salt water
3) Turtles and Tortoises (Order Testudines) Turtle lives in water; tortoises on land. Shell consists of dorsal carapace and ventral plastron.
4) Tuataras (Order Sphenodonta) Only living member. Lack external ears, scales, and have a third eye located on top of brain

19. Complete Section Assessment pg. 805 1-6
Reptile Review
Complete Section Assessment pg

20. Birds

21. Nonvertebrate chordates
Mammals
Birds
Reptiles
Amphibians
Fishes
Nonvertebrate chordates
Invertebrate ancestor

22. Silent Spring
Rachel Carson wrote the book Silent Spring in the 1960s. As the title suggests, she describes waking up on a spring morning, hearing none of the usual chirping of songbirds and wondering what happened to them. Carson’s book increased awareness of the use of pesticides in the environment. Unfortunately, one of the chemicals that had been used interfered with the formation of the shells of birds’ eggs.

23. With a partner, discuss and answer the questions that follow.
1. What effect would weak eggshells have on the population of birds? How might this cause a “silent spring”?
2. If you were a legislator, what would you do about the use of chemicals such as pesticides in our environment?

24. What is a bird? Reptilian-like animals
Maintain a constant internal body temp.
Outer covering of feathers
2 legs that are covered with scales and used for walking or perching
Front limbs modified into wings
Most of these features are adaptations for flight.

25. Feathers
Single most important characteristic that separates birds from living reptiles and other living animals
Made of protein
Develop from pits in birds skin
Help fly and to keep warm
2 types
1. Contour-provide lifting & balance needed for flight
2. Down-traps air close to body to keep warm

26. Form, Function, and Flight
1) Body Temperature Control
Endotherms – can generate their own heat
High metabolism – which produces heat
Feathers insulate body

27. Form, Function, and Flight
Adaptations enabling flight:
1. Highly efficient digestive, respiratory, and circulatory systems
2. Aerodynamic feathers and wings
3. Strong chest muscles

28. How does the bird’s skeletal system enable flight?
Fused bones provide sturdy attachments for muscles. Cross bracing and air spaces in the bones make them strong and lightweight.

29. 2) Feeding
Pathway of food: mouth, esophagus, crop, stomach, gizzard, intestines, cloaca
Any body heat must be regained by eating food. The more food a bird eats, the more energy its metabolism can generate.
Small birds must eat more because they lose heat faster
Beaks or bills are adapted to what type food they eat

30. Beaks or Bills Insect-eating birds have short, fine bills
Seed –eaters have short, thick bills
Carnivorous birds long, hooked bills to shred prey
Long, thin bills gather nectar from flowers or probing soft mud for worms
Large, long bills help to pick fruit from branches
Long, flat bills grasp fish

31. Digestive System
Birds have no teeth and cannot breakdown food by chewing. Have a crop that stores and moistens the food
From crop moves to stomach.
If they eat meat- have expandable area where large amounts of food can be stored
If they eat insects or seeds-have a muscular organ called gizzard that helps breakdown food by grinding it
Food moves from here to small intestine where food is absorbed into the body
Wastes leaves the body through the cloaca

32. Anatomy of a Pigeon When a bird eats, 1 food moves down
Brain
Esophagus
Lung
When a bird eats,
food moves down
the esophagus and
is stored in the crop.
Heart 1
Crop
Kidney
Air sac
Moistened food passes to the stomach, a two-part chamber. The first chamber secretes acid and enzymes. The partially digested food moves to the second chamber, the gizzard.
Liver 2
First chamber of stomach
Pancreas
Large intestine
Gizzard
Small intestine
Undigested food is
excreted through the
cloaca.
Cloaca 5
The muscular walls
of the gizzard squeeze
the contents, while small stones grind the food. 3
As digestion continues,
the food moves through
the intestines. 4

33. 3) Respiration
When a bird inhales, most air enters a large posterior air sac in the body cavity and bones
Air travels through a series of tubes in a single direction ensuring that lungs are constantly exposed to oxygen-rich air
Helps maintain high metabolic rate to maintain body temperature and flight. As well as, allowing birds to fly at oxygen depleted high altitudes

34. 4) Circulation Closed, double loop system
Heart has 4 chambers with a complete septum dividing heart into left and right halves
Pathway:
Right atrium receives oxygen poor blood from body and pumps this blood to lungs
Left atrium receives the oxygen rich blood and pumps this to body

35. Structure of a Bird’s Heart
Domestic pigeon
Right atrium
Left atrium
Right ventricle
Left ventricle
Heart
Complete division

36. 5) Excretion
Very similar to reptiles – nitrogenous waste is converted to uric acid, water is absorbed by body and a white paste is expelled from bird

37. 6) Response Brain is relatively large for animal’s size
Can see color very well
Can hear quite well
Taste and smell are NOT well developed

38. 7) Movement Most birds fly – Which ones cannot??
Skeleton is changed slightly to help a bird fly – near collarbone, hollow bones making skeleton more rigid. Form sturdy frame for muscles needed for flight
Large chest muscles that power the upward and downward wing strokes
Muscles attach to keel that runs down breastbone

39. Birds have the following adaptations to flight Wings Feathers
Strong chest muscles
Efficient respiratory system
Efficient circulatory system
which are
that also
that power
that provide
that ensure
Homologous to front limbs in other vertebrates
Provide warmth
Upward and downward wing strokes
One-way flow of O2-rich air
O2 distribution to body tissues

40. 8) Reproduction
Both male and female reproductive tracts open into the cloaca
Sex organs, which are internal, often shrink in size when not breeding
Mating birds press their cloacae together to transfer sperm to egg (some birds have penis)
Bird eggs are amniotic with a harder shell than reptile eggs

41. How does a chick get out of its shell?
When a chick is ready to hatch, it uses a small tooth on its bill to make a hole in the shell. After much poking and prodding the shell breaks open

42. Groups of Birds 30 different orders
Largest is the perching birds – songbirds. There are over 5000species
Other groups:
Pelicans
Parrots
Birds of Prey – owls, eagles, hawks
Cavity nesting birds – woodpeckers
Herons
Ostriches
Penguins

43. Bird Review 1) Are birds ectotherms or endotherms?
2) What characteristics do birds have in common?
3) How are birds adapted for flight?
Bonus: Are robins in Iowa year round?