Animal Systems: A Comprehensive Overview

1. Biology I Chapter 32 Introduction to Animals

2. What are the two organ systems that animals have that nothing else has? Do Now

3. Review Photosynthesis: 6 H2O + 6 CO2 + Sunlight C6H12O6 + 6 O2 Cellular Respiration: C6H12O6 + 6 O26 H2O + 6 CO2 What is missing? ATP Why is cellular respiration necessary for animals? Cellular respiration provides the energy cells need to support life activities

4. Definitions Animal-multicellular heterotrophic organisms that lack cell walls Vertebrate-have a backbone Invertebrate-do not have a backbone

5. Multicellularity Specialization-the evolutionary adaptation of a cell for a particular function Tissue-group of similar cells that perform a common function Organ-body structures that are composed of more than one type of tissue and that are specialized for a certain function

6. Heterotrophy Ingestion-an animal takes in organic material or food, usually in the form of other living things. Figure 18.1A

7. Sexual Reproduction Gamete-haploid cell Zygote-diploid cell

8. Differentiation-cells become specialized and therefore different from each other.

9. Movement Two types of tissues found only in animals: Nervous tissue Muscle tissue

10. Movement Nervous tissue-allows an animal to detect stimuli in its environment and within its own body Neurons-cells of nervous tissue that conduce electrical signals through an animals body

11. Neuron Dendrite-moves impulses toward the neuron Axon-moves impulses away from the neuron

12. Evolution Animals evolved from heterotrophic protists. Modern organisms that are thought to resemble the earliest animals are colonial protists

13. Origin and Classification Protostome-one digestive opening; “two-way traffic” Has mouth only Deuterostome-two digestive openings; “one-way traffic” Has mouth and anus

14. Molluscs Annelids Flatworms Arthropods Chordates Sponges Nematodes Cnidarians Echinoderms Deuterostomes Protostomes Bilaterians Radial symmetry Bilateral symmetry Eumetazoans No true tissues True tissues Figure 18.4 Ancestral colonial protist

15. Invertebrates Invertebrates-do not have a backbone Make up the greatest number of animal species

16. Chordates-4 Characteristics Notochord-firm, flexible rod of tissues located in the dorsal part of the body; becomes the vertebrae Dorsal nerve cord-hollow tube containing nerves; becomes the spinal cord

17. Pharyngeal pouches-small, outpockets of the digestive tract; becomes the gills or lungs • Post Anal Tail-consists of muscle tissue and lies behind the posterior opening of the digestive tract; becomes the tailbone or tail. Chordates

18. Body Plan Body Plan-describes an animal’s shape, symmetry, and internal organization

19. Symmetry-a body arrangement • Asymmetrical-do not display symmetry • Ex. Sponges

20. Radial Symmetry- body plan in which the parts are organized in a circle around an axis • Ex. Cnidarians

21. Body Plan Top Dorsal surface Bilateral symmetry-two similar halves on either side of a central plane Anterior end Posterior end Ventral surface Bottom Figure 18.3A

22. Body Plan Cephalization-characterized by the concentration of sensory and brain structures in the anterior end.

23. Body Plan Dorsal-back Ventral-front Anterior-toward the head Posterior-toward the tail

24. Germ layers Germ Layers-tissue layers in the embryos of all animals except sponges Coelom-fluid-filled hollow space found in higher animals

25. Embryonic Development Endoderm-Digestive system Mesoderm-Skeletal system Ectoderm-Nervous system

26. Body Cavity The body cavity aids movement by providing a firm, fluid-filled structure against which muscles can contract.

27. Anatomy Comparative anatomy-the study of the structure of animal bodies

28. Invertebrate Characteristics Most are radial, but the motile ones are bilateral. Segmentation-a body composed of a series of repeating similar units Exoskeleton-rigid outer covering that protects the soft tissues of many animals

29. Respiration and Circulation Gills-organs specialized for gas exchange in water. Open circulatory system-circulatory fluid is pumped by the heart through vessels and into the body cavity and is then returned to the vessels.

30. Invertebrate Reproduction Hermaphrodites-produce both male and female gametes.

31. Indirect development-have an intermediate larval stage • Larva-a free-living, immature form of an organism that is different from the adult.

32. Direct development-the young animal is born or hatched with the same appearance and way of life it will have as an adult; no larval stage occurs

33. Vertebrate Characteristics Endoskeleton-an internal skeleton made of bone and cartilage Integument-the outer covering of an animal Lung-organ for gas exchange

34. Vertebrate Characteristics Kidneys-filter wastes from the blood while regulating water levels in the body Vertebrates are not the first to have a brain, but are the first to have highly organized brains

35. Vertebrate Reproduction A major difference between the development of invertebrates and that of vertebrates is that most invertebrates undergo indirect development, while most vertebrates undergo direct development.

36. Embryonic developmental evidence suggests that echinoderms are closely related to chordates. • Crash Course Embryonic Development