2. Animals are:
* multicellular
* eukaryotic
* heterotrophs
* without cell
walls

3. Ex: Nerve cells carry impulses
Specialized cells carry out different tasks
Ex: Nerve cells carry impulses

4. Ex: Muscle cells contract and relax

5. There are 7 essential functions that all animals must perform in order to survive:
Feeding Respiration
Internal transport Excretion
Response Movement
Reproduction

6. Feeding
a. Herbivores – animals that eat plants

7. b. Carnivores – animals that eat other animals.

8. c. Parasites – animals that live on and absorb nutrients from a host.

9. d. Filter feeders – animals that strain zooplankton and phytoplankton from water.

10. e. Detritus feeders – animals that feed on tiny bits of decaying plants and animals.

11. 2. Respiration – animals consume oxygen and give off carbon dioxide in the process of cellular respiration.

12. To exchange oxygen and carbon dioxide, they must breathe by absorbing and giving off gases through their skins in water or by special organs such as gills or lungs

13. 3. Internal transport – animals must move nutrients, gases, and wastes from one part of the body to another so that all of the cells of the body are fed and wastes are removed.

14. Small animals with few cells may not need this system if water passing through their bodies takes care of it.
Diffusion is
process they
use.

15. Larger more complex animals have developed a circulatory system with a heart for pumping blood through blood vessels. Some parasites rely on the host for this process.

16. 4. Excretion – Cellular metabolism produces chemical wastes such as ammonia as well as solid wastes that must be eliminated or the animal will die.

17. Small primitive animals use the process of DIFFUSION through their cell membranes.

18. Larger animals have developed KIDNEYS for nitrogen wastes and openings from the intestine to an ANUS for solid wastes.

19. 5. Response – Animals must react to the STIMULI in their environments in order to obtain food, survive predators, and identify others of their own kind.

20. Sense organs gather information through specialized NERVE CELLS for seeing, hearing, touching, tasting, & smelling.

21. The BRAIN which is the NERVOUS SYSTEM’S control center, processes the information and regulates how the animal will react (RESPOND) to the information

22. 6. MOVEMENT – SESSILE animals live most of their lives attached to one spot.

23. MOTILE animals have a means of LOCOMOTION (movement) using tissues called MUSCLES that contract and expand to produce motion.

24. Muscles work together with the SKELETON or other system of body support to produce the motion.

25. Animals with an inside skeleton have an ENDOSKELETON.

26. An outside skeleton is called an EXOSKELETON
Empty dragonfly exoskeleton

27. 7. REPRODUCTION – animals must reproduce or their species will not survive. Lower animals reproduce both asexually and sexually.

28. Both methods of reproduction result in DIPLOID (2N) offspring
Both methods of reproduction result in DIPLOID (2N) offspring. Only the gametes (sperm & eggs) of animal parents are HAPLOID (having one set of chromosomes instead of a pair of chromosomes).
Ex: Haploid cells are Egg & Sperm

29. Higher animals tend to lose the ability to reproduce asexually and usually bear their young alive.

30. Some lay eggs. Some eggs hatch into miniature adults (look like the adult). Some eggs hatch into LARVAE, which are immature stages that do not look like the adult. They undergo INDIRECT DEVELOPMENT called METAMORPHOSIS from the larval stage to the adult stage, sometimes with intermediate stages between them.

31. Section 28.2 Summary – pages 747 - 755
Metamorphosis: Change in body shape and form
These insects go through successive molts until the adult size is reached.
Molt
Nymph
Eggs
Nymph
Molt
Adult
Section 28.2 Summary – pages

32. Section 28.2 Summary – pages 747 - 755
Metamorphosis: Change in body shape and form
In some cases, the adult insect bears little resemblance to its juvenile stage.
Adult
Egg
Larva
Pupa
Section 28.2 Summary – pages

33. Section 28.2 Summary – pages 747 - 755
Metamorphosis: Change in body shape and form
The larva is the free-living, wormlike stage of an insect, often called a caterpillar.
Section 28.2 Summary – pages

34. Section 28.2 Summary – pages 747 - 755
Metamorphosis: Change in body shape and form
larvae
fertilized egg
The complete metamorphosis of a butterfly is illustrated.
adult
pupa
Section 28.2 Summary – pages

35. Section 28.2 Summary – pages 747 - 755
Incomplete metamorphosis has three stages
A nymph, which hatches from an egg, has the same general appearance as the adult but is smaller.
Molt
Nymph
Eggs
Nymph
Molt
Adult
Section 28.2 Summary – pages

36. Section 28.2 Summary – pages 747 - 755
Incomplete metamorphosis has three stages
Grasshoppers and cockroaches are insects that undergo incomplete metamorphosis.
Incomplete metamorphosis of a harlequin bug
Section 28.2 Summary – pages

37. TRENDS IN ANIMAL EVOLUTION
1. The levels of organization become higher as animals become more complex in form. The division of labor becomes more complex with cells producing tissues, and tissues producing organs, and organs producing organ systems.

38. SYMMETRY in animals changes from simple form to higher forms:
Spherical – Spheres such as algal cells are seldom found in animals.
Exception:
Sea Urchin

39. Section 25.2 Summary – pages 680 - 685
Asymmetry
An animal that is irregular in shape has no symmetry or an asymmetrical body plan.
Animals with no symmetry often are sessile organisms that do not move from place to place.
Most adult sponges do not move about.
Section 25.2 Summary – pages

40. b. RADIAL – Have no head. Look like a cylinder shape or barrel
b. RADIAL – Have no head. Look like a cylinder shape or barrel. Usually sessile or float in water.

41. Section 25.2 Summary – pages 680 - 685
Radial symmetry
Animals with radial symmetry can be divided along any plane, through a central axis, into roughly equal halves.
Section 25.2 Summary – pages

42. c. BILATERAL – found in higher animals
c. BILATERAL – found in higher animals. Have a head (ANTERIOR) region and tail (POSTERIOR) region, as well as a bottom (VENTRAL) side and a top (DORSAL) side.

44. Section 25.2 Summary – pages 680 - 685
Bilateral symmetry
An organism with bilateral symmetry can be divided down its length into similar right and left halves.
Section 25.2 Summary – pages

45. More complex animals tend to have a concentration of sense organs and nerve cells in the anterior end (CEPHALIZATION).
The “BRAIN” may be little more than a cluster of nerve cells called GANGLIA in the lower animals but becomes a true brain in higher animals.

46. LOWER INVERTEBRATES
Phylum Porifera – sponges with cellular level organization

47. Phylum Cnideria – Soft bodied animals with 2 tissues called ectoderm (epidermis) and endoderm (gastrodermis) with a gelatinous substance in between called mesoglea.

48. Phylum Platyhelminthes – Flat worms with 3 tissues, ectoderm, endoderm, and mesoderm. Have a digestive cavity but no COELOM (fully lined body cavity).

49. Phylum Nematoda – Round worms with 3 tissues, ectoderm endoderm, and mesoderm. Have a partially lined body cavity called a PSEUDOCOELOM (false coelom).

50. In most animals, three cell layers form during embryo development.
1. Ectoderm (outer layer) gives rise to the skin, nerves, and sense organs.

51. Section 25.1 Summary – pages 673 - 679
Gastrulation
Ectoderm
The ectoderm cells of the gastrula continue to grow and divide, and eventually they develop into the skin and nervous tissue of the animal.
Section 25.1 Summary – pages

52. 2. Endoderm (inner layer) gives rise to the digestive tract and respiratory system.
3. Mesoderm (middle layer) gives rise to the circulatory system, muscles, and reproductive and excretory organs.

53. Section 25.1 Summary – pages 673 - 679
Gastrulation
The endoderm cells develop into the lining of the animal’s digestive tract and into organs associated with digestion.
Endoderm
Section 25.1 Summary – pages

54. Section 25.1 Summary – pages 673 - 679
Formation of mesoderm
Mesoderm is found in the middle of the embryo; the term meso means “middle.”
Mesoderm
The mesoderm is the third cell layer found in the developing embryo between the ectoderm and the endoderm.
Section 25.1 Summary – pages

55. Animals that have a true coelom (fully lined body cavity), are called COELOMATES.
In a pseudocoelom, the mesoderm cells line the ectoderm side of the body cavity but not the endoderm side.

56. Section 25.2 Summary – pages 680 - 685
Pseudocoelomates
Pseudocoelomate Roundworm
A roundworm is an animal with bilateral symmetry.
Ectoderm
Mesoderm
Endoderm
The body of a roundworm has a space that develops between the endoderm and mesoderm.
Body cavity
Digestive tract
Section 25.2 Summary – pages

57. Section 25.2 Summary – pages 680 - 685
Pseudocoelomates
Pseudocoelomate Roundworm
It is called a pseudocoelom—a fluid-filled body cavity partly lined with mesoderm.
Ectoderm
Mesoderm
Endoderm
Body cavity
Digestive tract
Pseudocoelom
Section 25.2 Summary – pages

58. Section 25.2 Summary – pages 680 - 685
Pseudocoelomates
Pseudocoelomates have a one-way digestive tract that has regions with specific functions.
The mouth takes in food, the breakdown and absorption of food occurs in the middle section, and the anus expels waste.
Intestine
Anus
Mouth
Round body shape
Section 25.2 Summary – pages

59. Coelomates, which include all vertebrates and many invertebrates, are animals with the most specialized body structures. The coelom provides a place for the development of more complex organ systems.

60. Section 25.2 Summary – pages 680 - 685
Coelomates
Coelomate Segmented Worm
The body cavity of an earthworm develops from a coelom, a fluid-filled space that is completely surrounded by mesoderm.
Ectoderm
Mesoderm
Endoderm
Body cavity
Digestive tract
The greatest diversity of animals is found among the coelomates.
Coelom
Section 25.2 Summary – pages

61. The fluid-filled space cushions internal organs and keeps them from being affected by the movement of surrounding muscles.

62. Because their muscles are not restricted by internal organs, coelomates can move freely without changing the shape or position of the internal organs.
THE END

63. THE END