1. Introduction to Animals
Biology I Chapter 32
Introduction to Animals

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

3. Review Photosynthesis: Cellular Respiration: What is missing?
H2O + CO2 + Sunlight C6H12O6 + O2
Cellular Respiration:
C6H12O6 + O2H2O + 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. Gamete-haploid cell Zygote-diploid cell
Sexual Reproduction
Gamete-haploid cell
Zygote-diploid cell

8. Differentiation-cells become specialized and therefore
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. Figure 18.4 Sponges Cnidarians Chordates Flatworms Molluscs Annelids
Arthropods
Echinoderms
Nematodes
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. Chordates
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.

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
Bilateral symmetry-two similar halves on either side of a central plane
Top
Dorsal surface
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. 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 Development
Embryonic developmental evidence suggests that echinoderms are closely related to chordates.
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