29-2 Form and Function in Invertebrates Slide 1 of 52

Size: px

Start display at page:

Download "29-2 Form and Function in Invertebrates Slide 1 of 52"

Scott West
5 years ago
Views:

1 29-2 Form and Function in 1 of 52

2 How do different invertebrate phyla carry out life functions? 2 of 52

3 Feeding and Digestion Feeding and Digestion The simplest animals break down food primarily through intracellular digestion. More complex animals use extracellular digestion. 3 of 52

4 Feeding and Digestion When food is digested inside cells, this process is known as intracellular digestion. Sponges use intracellular digestion. 4 of 52

5 Feeding and Digestion In extracellular digestion, food is broken down outside the cells in a digestive cavity or tract and then absorbed into the body. Mollusks, annelids, arthropods, and echinoderms rely almost entirely on extracellular digestion. Flatworms and cnidarians use both intracellular and extracellular digestion. 5 of 52

6 Feeding and Digestion Cnidarians and most flatworms ingest food and expel wastes through a single opening. Food is digested in a cavity through both extracellular and intracellular means. 6 of 52

7 Feeding and Digestion Invertebrate Digestive Systems Mouth/anus Gastrovascular cavity Pharynx Digestive cavity Cnidarian Mouth/anus Flatworm 7 of 52

8 Feeding and Digestion In more-complex animals, food enters the mouth and wastes leave through the anus. A one-way digestive tract often has specialized regions. 8 of 52

9 Intestine Feeding and Digestion Annelid Gizzard Crop Pharynx Mouth Anus Pharynx Crop Anus Arthropod Mouth Stomach and digestive glands Intestine Rectum 9 of 52

10 Respiration Respiration All respiratory systems have two basic requirements: a large surface area that is in contact with the air or water the respiratory surfaces must be moist for diffusion to occur 10 of 52

11 Respiration Aquatic Many animals respire through their skin. Aquatic mollusks, arthropods, and many annelids exchange gases through gills. 11 of 52

12 Respiration Gills are feathery structures that expose a large surface area to the water. 12 of 52

13 Respiration Terrestrial Terrestrial invertebrates have several types of respiratory surfaces. Many spiders have book lungs. 13 of 52

14 Respiration Grasshoppers and other insects have spiracles and tracheal tubes. 14 of 52

15 Circulation Circulation Most complex animals have one or more hearts to move blood through their bodies and either an open or closed circulatory system. 15 of 52

16 Circulation Open Circulatory Systems In an open circulatory system, blood is only partially contained within a system of blood vessels. One or more hearts or heartlike organs pump blood through blood vessels into a system of sinuses, or spongy cavities. The blood makes its way back to the heart. 16 of 52

17 Circulation Open circulatory systems are characteristic of arthropods and most mollusks. 17 of 52

18 Circulation Closed Circulatory Systems In a closed circulatory system, a heart or heartlike organ forces blood through vessels that extend throughout the body. Materials reach body tissues by diffusing across the walls of the blood vessels. Closed circulatory systems are characteristic of larger, more active animals. 18 of 52

19 Circulation Among the invertebrates, closed circulatory systems are found in annelids and some mollusks. Heartlike structure Small vessels in tissue Annelid: Closed Circulatory System Heartlike structures Blood vessels 19 of 52

20 Excretion Excretion Most animals have an excretory system that rids the body of metabolic wastes while controlling the amount of water in the tissues. In aquatic invertebrates, ammonia diffuses from their body tissues into the surrounding water. 20 of 52

21 Excretion Flatworms use a network of flame cells to eliminate excess water. Flame Cells Excretory tubules Flame Cell Flatworm Excretory tubule 21 of 52

22 Excretion In annelids and mollusks, urine forms in tubelike structures called nephridia. Nephrostome Excretory pore Annelid Nephridia 22 of 52

23 Excretion Fluid enters the nephridia through openings called nephrostomes. Urine leaves the body through excretory pores. Urine is highly concentrated, so little water is lost. 23 of 52

24 Excretion Some insects and arachnids have Malpighian tubules, saclike organs that convert ammonia into uric acid. Digestive tract Arthropod Malpighian tubules 24 of 52

25 Excretion Uric acid and digestive wastes combine to form a thick paste that leaves the body through the rectum. The paste helps to reduce water loss. 25 of 52

26 Response Response show three trends in the evolution of the nervous system: centralization, cephalization, and specialization. 26 of 52

27 Response Centralization and Cephalization Cephalization is the concentration of nerve tissue and organs in one end of the body. 27 of 52

28 Response Cnidarians have nerve nets which consist of individual nerve cells that form a netlike arrangement throughout the animal s body. Nerve cells Cnidarian 28 of 52

29 Response In flatworms and roundworms, the nerve cells are more centralized. Ganglia There are a few clumps of nerve tissue, or ganglia, in the head. Flatworm 29 of 52

30 Response In cephalopod mollusks and arthropods, ganglia are organized into a brain. Brain Arthropod Ganglia Brain Mollusk 30 of 52

31 Response Specialization The more complex an animal s nervous system is, the more developed its sense organs tend to be. Complex animals may have a variety of specialized sense organs that detect light, sound, chemicals, movement, and electricity. 31 of 52

32 Movement and Support Movement and Support Most animals use muscles to move, breathe, pump blood, and perform other life functions. In most animals, muscles work together with some sort of skeletal system that provides firm support. 32 of 52

33 Movement and Support have one of three main kinds of skeletal systems: hydrostatic skeletons, exoskeletons, or endoskeletons. 33 of 52

34 Movement and Support Hydrostatic Skeletons In a hydrostatic skeleton, muscles surround a fluid-filled body cavity that supports the muscles. When the muscles contract, they push against fluid in the body cavity, causing the body to change shape. Annelids and certain cnidarians, have hydrostatic skeletons. 34 of 52

35 Movement and Support Hydrostatic Skeleton Water Circular muscles contracted Longitudinal muscles contracted Water 35 of 52

36 Movement and Support Exoskeletons An exoskeleton, or external skeleton, is a hard body covering made of chitin. Arthropods have exoskeletons. Arthropods move by using muscles that are attached to the inside of the exoskeleton. 36 of 52

37 Movement and Support Exoskeleton Flexed joint Extended joint 37 of 52

38 Movement and Support Endoskeletons An endoskeleton is a structural support located inside the body. Sea stars and other echinoderms have an endoskeleton. Vertebrates also have endoskeletons. 38 of 52

39 Movement and Support Endoskeleton Skeletal plates Tube foot 39 of 52

40 Sexual and Asexual Reproduction Sexual and Asexual Reproduction Most invertebrates reproduce sexually during at least part of their life cycle. Depending on environmental conditions, however, many invertebrates may also reproduce asexually. 40 of 52

41 Sexual and Asexual Reproduction Sexual reproduction maintains genetic diversity in a population. Asexual reproduction allows animals to reproduce rapidly and take advantage of favorable conditions in the environment. 41 of 52

42 Sexual and Asexual Reproduction Sexual reproduction is the production of offspring from the fusion of gametes. Male and female gametes join to create a zygote. The zygote grows through mitosis and develops into a multicellular animal. 42 of 52

43 Sexual and Asexual Reproduction In most animals, each individual is a single sex. The individual produces either sperm or eggs. Some animals are hermaphrodites individuals that produce both sperm and eggs. 43 of 52

44 Sexual and Asexual Reproduction In external fertilization, eggs are fertilized outside the female s body. In internal fertilization, eggs are fertilized inside the female s body. 44 of 52

45 Sexual and Asexual Reproduction The offspring of asexual reproduction grow into multicellular organisms by mitosis of diploid cells. Some animals reproduce asexually through budding or by dividing in two. 45 of 52

46 29-2 Continue to: - or - Click to Launch: 46 of 52

47 29-2 Flatworms eliminate excess water using a network of a. flame cells. b. Malpighian tubules. c. nephridia. d. madrepores. 47 of 52

48 29-2 A hydrostatic skeleton is found in the a. annelids. b. echinoderms. c. arthropods. d. insects. 48 of 52

49 29-2 Complex animals break down food using a. intracellular digestion. b. extracellular digestion. c. intracellular digestion and extracellular digestion. d. digestion outside of the body. 49 of 52

50 29-2 Which structures are involved in gas exchange in one or more groups of invertebrates? a. ganglia, brain, and nerve cells b. gills, book lung, skin, and tracheal tubes c. nephridia, flame cells, and nephrostomes d. pharynx, crop, and intestine 50 of 52

51 29-2 Which groups have only one entrance and exit point to the digestive system? a. annelids and echinoderms b. arthropods and roundworms c. mollusks and sponges d. flatworms and cnidarians 51 of 52

52 END OF SECTION

Flatworms. Phylum Platyhelminthes

Flatworms. Phylum Platyhelminthes Flatworms Phylum Platyhelminthes Characteristics of Flatworms Flatworms are acoelomates, which means they have no coelom. A coelom is a fluid-filled body cavity The digestive cavity is the only body cavity