ZOOLOGY—STUDY OF ANIMALS

1. Life began over 600 million years ago The evolution of animals includes the appearance of: multicellularity coelom notocord vertebrae homeothermy ZOOLOGY—STUDY OF ANIMALS

2. An Introduction to Animals Characteristics of Kingdom Animalia

3. Characteristics of Animals • Multicellular with specialized cells: the bodies of animals contain more than one cell. The cells are specialized. These cells do not lead independent lives, but have specialized structures and functions

4. Characteristics of Animals • Multicellular with specialized cells • Eukaryotes: cells contain membrane-enclosed nuclei (except mature human red blood cells) and have membrane-enclosed organelles.

5. Characteristics of Animals • Multicellular with specialized cells • Eukaryotes • Heterotrophs: Not capable of manufacturing their own food and must rely on external food sources

6. Characteristics of Animals • Multicellular with specialized cells • Eukaryotes • Heterotrophs • Cells lack cell walls and photosynthetic organelles: Have no rigid structure surrounding the cell membrane and no chloroplasts to convert CO2 and water into carbohydrates.

7. Characteristics of Animals • Multicellular • Eukaryotes • Heterotrophs • Cells lack cell walls and photosynthetic organelles And most can 5. Reproduce sexually: Have male and female gonads that produce gametes which fuse to produce offspring. Some species have separate sexes, some do not.

8. Characteristics of Animals • Multicellular • Eukaryotes • Heterotrophs • Cells lack cell walls and photosynthetic organelles And most can 5. Reproduce sexually 6. Move: Some species have the ability to move their entire body; some have only cells with motile structures (cilia and flagella). Some species are motile (move) in the larval stage and sessile (do not move) in the adult stage.

9. What kingdom characteristics separates animals from plants?

10. What kingdom characteristics separates animals from plants? • Members of the plant kingdom are autotrophic while all animals are heterotrophic. • Members of the plant kingdom have cell walls and photosynthetic organelles

11. Extremes in the animal world • This species is called a 'fangtooth' and it is one of the deepest-dwelling fish in the sea.

12. Extremes in the animal world

13. The Goliath beetle • Invertebrate

14. When studying and describing animals, some basic body characteristics are important. These include: • Body symmetry - the way body parts are arranged around a point or central axis.

15. When studying and describing animals, some basic body characteristics are important. These include: • Body symmetry • Directions on the body - used to describe areas on the body of an animal.

16. When studying and describing animals, some basic body characteristics are important. These include: • Body symmetry • Directions on the body • Body cavities – fluid-filled space that forms between the digestive tract and the outer wall of the body.

17. When studying and describing animals, some basic body characteristics are important. These include: • Body symmetry • Directions on the body • Body cavities • Formation of germ layers - layers of specialized cells in the early development.

18. When studying and describing animals, some basic body characteristics are important. These include: • Body symmetry • Directions on the body • Body cavities • Formation of germ layers • Pattern of body development - a sequence of developmental steps.

19. When studying and describing animals, some basic body characteristics are important. These include: • Body symmetry • Directions on the body • Body cavities • Formation of germ layers • Pattern of body development • Body structure and relatedness – using similarities in body plans and patterns of development to classify and determine the evolutionary history of animals

20. When studying and describing animals, some basic body characteristics are important. These include: • Body symmetry • Directions on the body • Body cavities • Formation of germ layers • Pattern of body development • Body structure and relatedness These are all important parts of Animal Body Plans!

21. Animal Body Plans • Animals are made up of a complex system of cells. • Cells make up different tissues of animal’s bodies. • Tissues make up different organs in animal’s bodies. • And organs make up different organ systems.

22. Types of symmetry: • Spherical-sphere-shaped, the body can be divided into two identical parts by any plane passing through the center.

23. Types of symmetry: • Radial-the body can be divided into two identical halves by any plane that passes through the longitudinal axis.

24. Types of symmetry: • Bilateral-the body can be divided into two identical halves by only one specific plane passing through the longitudinal axis.

25. Types of symmetry: • Asymmetry-the body has no definite shape and cannot be divided into two identical halves.

26. Anatomical Orientation • When studying the anatomy of animals, it is necessary to use terminology to describe directions, planes, and points of reference. • Anterior/Posterior: A direction on an animals body referring to towards the head and/or tail. • Dorsal/Ventral: A direction on an animals body referring to towards the spine and/or belly. • Medial/Lateral: A direction referring to towards or away from the midline or mid-sagittal plane of the body. • Distal/Proximal: A direction referring to farther away from and closer to another point of reference.

27. Anatomical Orientation

28. Anatomical Orientation • Sagittal plane: An imaginary line or axis that goes through the body separating left and right halves. • Frontal plane: An imaginary line or axis that goes through the body separating dorsal and ventral halves or sections. • Transverse plane: An imaginary line or axis that goes through the body separating anterior and posterior halves or sections. • Oral/Aboral: Animals with radial symmetry, oral refers to the mouth side, aboral is opposite of oral.

29. Anatomical Orientation

30. Body Planes Ways in which the body of a bilaterally symmetrical animal can be divided: • Sagittal Plane – divides the body into left and right halves • Frontal Plane – divides the body into dorsal and ventral halves • Transverse Plane – divides the body into anterior and posterior halves

31. The three planes are perpendicular to each other

32. Cephalization: the concentration of sensory and brain structures in the anterior end of the animal.

33. Cephalization • Nervous tissue, composed of nerve cells called neurons, is found only in animals. Along with muscle tissue, nervous tissue allows animals to sense and respond their environment. • By concentrating these sense receptors at the "head" of an animal, the animal is able to respond to its environment more quickly.

34. Cephalization Animals can be: • Highly cephalized • Slightly cephalized • Not cepahlized

35. Segmentation • Metamerism: a serial (in a series) repetition (repeating) of similar body segments along the longitudinal axis of the body.

36. Sexual Reproduction: involves the joining of sperm and egg cells.

37. Insects are invertebrates

38. Insects are invertebrates END OF SECTION

39. Pattern of body development:

40. Pattern of body development: • Zygote- the fertilized egg.

41. Pattern of body development: • Zygote- the fertilized egg. • Embryo - As the fertilized egg begins to divide, the cells in the resulting mass are identical. At some point (about 32 cells), this packed mass of cells quickly spreads into a hollow sphere of cells. This point is called blastulation and is the beginning of cell divergence.

42. Embryo • Blastula-a hollow sphere of cells. • Blastopore - the point where folding begins. • Gastrula-as the blastula enlarges,it cups inward on one side.

44. Vertebrate embryos look very much alike in their early development.

45. Fetus - the embryo developed to the point that it begins to resemble the mature organism.

46. Germ layers: • Specialization of body tissues is common in animals. • During gastrulation, two or three "germ layers" form. • These layers of cells become specific structures and organs in the animal.

47. Germ layers: • Ectoderm - cells on the outside of the gastrulathat become the body covering. • Mesoderm - a middle layer of cells that formsthe muscles and interior organs. • Endoderm - cells on the inside of the gastrulathat become the lining of the gut.

48. Embryonic Development: • The development of an organism involves an increase in mass and structure. Both these changes come from an increase in cell number (due to mitosis), enlargement of cells and specialization of cells.

49. All division starts from a single, fertilized egg cell, the zygote.

50. Early Embryonic Development • After fertilization of an egg occurs, the egg becomes a zygote. Then, a zygote’s cells begin dividing in a process called cleavage. • Some animals (like echinoderms and chordates) exhibit radial cleavage, in which the cleavage planes are symmetrical. • Other animals (like molluscs and annelids) exhibit spiral cleavage, in which the cells divide in a spiral or asymmetrical pattern.