End Show Slide 1 of 49 Copyright Pearson Prentice Hall Biology

End Show Slide 2 of 49 Copyright Pearson Prentice Hall 26-1 Introduction to the Animal Kingdom

End Show 26-1 Introduction to the Animal Kingdom Slide 3 of 49 Copyright Pearson Prentice Hall What Is an Animal? What characteristics do all animals share?

End Show 26-1 Introduction to the Animal Kingdom Slide 4 of 49 Copyright Pearson Prentice Hall What Is an Animal? Animals are multicellular, eukaryotic heterotrophs whose cells lack cell walls.

End Show 26-1 Introduction to the Animal Kingdom Slide 5 of 49 Copyright Pearson Prentice Hall What Is an Animal? Animals have the following types of tissues: epithelial muscular connective nervous

End Show 26-1 Introduction to the Animal Kingdom Slide 6 of 49 Copyright Pearson Prentice Hall What Is an Animal? Epithelial tissues cover body surfaces. Muscle tissue cells contain proteins that enable them to contract, moving parts of animals’ bodies. Connective tissues support an animal’s body and connect its parts. Nervous tissue contains nerve cells, which carry information throughout the body.

End Show 26-1 Introduction to the Animal Kingdom Slide 7 of 49 Copyright Pearson Prentice Hall What Is an Animal? Invertebrates make up 95% of all animal species. Invertebrates do not have a backbone, or vertebral column. They include sea stars, worms, jellyfishes, and insects.

End Show 26-1 Introduction to the Animal Kingdom Slide 8 of 49 Copyright Pearson Prentice Hall What Is an Animal? The other 5% of animals are vertebrates. Vertebrates have a backbone. Vertebrates include fishes, amphibians, reptiles, birds, and mammals.

End Show 26-1 Introduction to the Animal Kingdom Slide 9 of 49 Copyright Pearson Prentice Hall What Animals Do to Survive What essential functions do animals carry out?

End Show 26-1 Introduction to the Animal Kingdom Slide 10 of 49 Copyright Pearson Prentice Hall What Animals Do to Survive Animals carry out the following essential functions: feeding respiration circulation excretion response movement reproduction

End Show 26-1 Introduction to the Animal Kingdom Slide 11 of 49 Copyright Pearson Prentice Hall What Animals Do to Survive Many body functions help animals maintain homeostasis, or a relatively stable internal environment. Homeostasis is often maintained by internal feedback mechanisms called feedback loops. Most feedback loops involve feedback inhibition, in which the product or result of a process stops or limits the process.

End Show 26-1 Introduction to the Animal Kingdom Slide 12 of 49 Copyright Pearson Prentice Hall What Animals Do to Survive Feeding Herbivores eat plants. Carnivores eat other animals. Omnivores feed on both plants and animals. Detritivores feed on decaying plant and animal material. Filter feeders are aquatic animals that strain tiny floating organisms from water.

End Show 26-1 Introduction to the Animal Kingdom Slide 13 of 49 Copyright Pearson Prentice Hall What Animals Do to Survive Animals can also form symbiotic relationships, in which two species live in close association with each other.

End Show 26-1 Introduction to the Animal Kingdom Slide 14 of 49 Copyright Pearson Prentice Hall What Animals Do to Survive Respiration Whether they live in water or on land, all animals respire—they take in oxygen and give off carbon dioxide.

End Show 26-1 Introduction to the Animal Kingdom Slide 15 of 49 Copyright Pearson Prentice Hall What Animals Do to Survive Circulation Animals transport oxygen, nutrient molecules, and waste products among all their cells through either simple diffusion or some kind of circulatory system

End Show 26-1 Introduction to the Animal Kingdom Slide 16 of 49 Copyright Pearson Prentice Hall What Animals Do to Survive Excretion Ammonia is a waste product of cells and a poisonous substance. Most animals have an excretory system that eliminates ammonia quickly or converts it into a less toxic substance that is removed from the body.

End Show 26-1 Introduction to the Animal Kingdom Slide 17 of 49 Copyright Pearson Prentice Hall What Animals Do to Survive Response Animals respond to events in their environment using specialized cells, called nerve cells. In most animals, nerve cells form a nervous system. Receptor cells respond to sound, light, and external stimuli. Other nerve cells process information and determine how the animal responds.

End Show 26-1 Introduction to the Animal Kingdom Slide 18 of 49 Copyright Pearson Prentice Hall What Animals Do to Survive Movement Some animals stay at a single spot, but most can move. Most animals have muscles or musclelike tissues. Muscle contraction enables motile animals to move around by working in combination with a support structure called a skeleton. Muscles also help even sedentary animals feed and pump water and fluids through their bodies.

End Show 26-1 Introduction to the Animal Kingdom Slide 19 of 49 Copyright Pearson Prentice Hall What Animals Do to Survive Reproduction Most animals reproduce sexually. This helps to create and maintain genetic diversity in populations and improve species’ abilities to evolve when the environment changes. Many invertebrates can also reproduce asexually. This produces offspring that are genetically identical to the parent. It allows animals to increase their numbers rapidly.

End Show 26-1 Introduction to the Animal Kingdom Slide 20 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution What are the important trends in animal evolution?

End Show 26-1 Introduction to the Animal Kingdom Slide 21 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution Complex animals tend to have: high levels of cell specialization and internal body organization bilateral body symmetry a front end or head with sense organs a body cavity

End Show 26-1 Introduction to the Animal Kingdom Slide 22 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution Cell Specialization and Levels of Organization As animals have evolved, their cells have become specialized to carry out different functions. In multicellular organisms, each cell type has a structure and chemical composition that enable it to perform a specialized function.

End Show 26-1 Introduction to the Animal Kingdom Slide 23 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution Groups of specialized cells form tissues. Tissues join together to form organs and organ systems—all of which work together to carry out a variety of complex functions.

End Show 26-1 Introduction to the Animal Kingdom Slide 24 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution Early Development Animals that reproduce sexually begin life as a zygote, or fertilized egg.

End Show 26-1 Introduction to the Animal Kingdom Slide 25 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution The zygote undergoes a series of divisions to form a blastula, a hollow ball of cells.

End Show 26-1 Introduction to the Animal Kingdom Slide 26 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution The blastula folds in on itself, forming a single opening called a blastopore. The blastopore leads into a central tube that runs the length of the developing embryo. This tube becomes the digestive tract and is formed in one of two ways.

End Show 26-1 Introduction to the Animal Kingdom Slide 27 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution A protostome is an animal whose mouth is formed from the blastopore. Most invertebrate animals are protostomes. Blastopore Endoderm Mesoderm Blastopore becomes mouth Anus Ectoderm

End Show 26-1 Introduction to the Animal Kingdom Slide 28 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution A deuterostome is an animal whose anus is formed from the blastopore. The anus is the opening through which wastes leave the digestive tract. Blastopore becomes anus Mouth Ectoderm Mesoderm Endoderm Blastopore

End Show 26-1 Introduction to the Animal Kingdom Slide 29 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution Echinoderms and vertebrates are both deuterostomes.

End Show 26-1 Introduction to the Animal Kingdom Slide 30 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution This similarity in embryology may indicate that vertebrates have a closer evolutionary relationship to echinoderms than to other invertebrates.

End Show 26-1 Introduction to the Animal Kingdom Slide 31 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution During early development, the cells of most animal embryos differentiate into three layers called germ layers.

End Show 26-1 Introduction to the Animal Kingdom Slide 32 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution The cells of the endoderm, or innermost germ layer, develop into the linings of the digestive tract and much of the respiratory system. Only the label “endoderm” should appear on this slide. Endoderm

End Show 26-1 Introduction to the Animal Kingdom Slide 33 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution The cells of the mesoderm, or middle layer, develop into muscles and much of the circulatory, reproductive, and excretory organ systems. Mesoderm

End Show 26-1 Introduction to the Animal Kingdom Slide 34 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution The ectoderm, or outermost layer, develops into the sense organs, nerves, and the outer layer of the skin. Ectoderm

End Show 26-1 Introduction to the Animal Kingdom Slide 35 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution Body Symmetry Except for sponges, every animal exhibits some body symmetry in its structure. Many simple animals, like the sea anemone, have body parts that repeat around the center of the body.

End Show 26-1 Introduction to the Animal Kingdom Slide 36 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution These animals exhibit radial symmetry, in which any number of imaginary planes can be drawn through the center, each dividing the body into equal halves. Planes of symmetry Radial symmetry

End Show 26-1 Introduction to the Animal Kingdom Slide 37 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution Bilateral symmetry Plane of symmetry In animals with bilateral symmetry, only one imaginary plane can divide the body into two equal halves—left and right.

End Show 26-1 Introduction to the Animal Kingdom Slide 38 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution Posterior end Anterior end Bilateral symmetry The anterior is the front end. The posterior is the back end.

End Show 26-1 Introduction to the Animal Kingdom Slide 39 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution Dorsal side The dorsal is the upper side. The ventral is the lower side. Ventral side Bilateral symmetry

End Show 26-1 Introduction to the Animal Kingdom Slide 40 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution Bilateral symmetry allows for segmentation, in which the body is constructed of many repeated and similar parts, or segments. The combination of bilateral symmetry and segmentation is found in two successful animal groups—arthropods and vertebrates.

End Show 26-1 Introduction to the Animal Kingdom Slide 41 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution Cephalization Animals with bilateral symmetry exhibit cephalization, which is the concentration of sense organs and nerve cells at the front end of the body.

End Show 26-1 Introduction to the Animal Kingdom Slide 42 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution Animals with bilateral symmetry usually move with the anterior end forward, so this end comes in contact with new parts of the environment first. As sense organs have evolved, they have tended to gather at the anterior end, as have nerve cells that process information and “decide” what the animal should do.

End Show 26-1 Introduction to the Animal Kingdom Slide 43 of 49 Copyright Pearson Prentice Hall Trends in Animal Evolution Body Cavity Formation Most animals have a body cavity, a fluid-filled space between the digestive tract and body wall. A body cavity provides a space in which internal organs can be suspended so that they are not pressed on by muscles or twisted out of shape by body movements.

End Show - or - Continue to: Click to Launch: Slide 44 of 49 Copyright Pearson Prentice Hall 26-1

End Show Slide 45 of 49 Copyright Pearson Prentice Hall 26-1 Homeostasis is often maintained by feedback loops that involve a.gastrulation. b.feedback inhibition. c.spontaneous generation. d.equilibrium.

End Show Slide 46 of 49 Copyright Pearson Prentice Hall 26-1 Animals respond to events in their environments using specialized cells called a.muscle cells. b.nerve cells. c.gametes. d.blood cells.

End Show Slide 47 of 49 Copyright Pearson Prentice Hall 26-1 A characteristic that all animals share is being a.heterotrophic. b.autotrophic. c.prokaryotic. d.anaerobic.

End Show Slide 48 of 49 Copyright Pearson Prentice Hall 26-1 Excretion is a function of all animals that involves a.exchange of oxygen and carbon dioxide. b.transport of material from one part of the body to another. c.digestion and absorption of food molecules. d.removal of metabolic wastes.

End Show Slide 49 of 49 Copyright Pearson Prentice Hall 26-1 One major trend in animal evolution has been a.the simplification of body organ systems. b.an increase in the degree of cephalization. c.a shift from bilateral symmetry to radial symmetry. d.disappearance of the blastula stage in early development.

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