Presentation is loading. Please wait.

Presentation is loading. Please wait.

ANIMALS Chapters 25 and 26.

Similar presentations

Presentation on theme: "ANIMALS Chapters 25 and 26."— Presentation transcript:

1 ANIMALS Chapters 25 and 26

2 Chapter 25.1 and 25.2 Objectives
List the characteristics that all animals share. Differentiate between invertebrates and chordates. Describe some features of animal body plans.

3 Characteristics of Animals
Heterotrophic Multi-cellular Eukaryotic No cell walls Heterotrophic – obtain nutrients and energy by eating other organisms Eukaryotic – cells have a nucleus and membrane-bound organelles

4 Types of Animals Invertebrates – 95% of animals Lack a backbone
Examples: Jellyfish Seastar Worm Insect

5 Types of Animals Chordates – 5% of animals Characteristics:
Dorsal, hollow nerve chord Notochord Long supporting rod running length of body Tail extending past anus Pharyngeal pouches Paired structures in throat region Most are vertebrates (animals with backbones) Examples: fish, amphibians, reptiles, birds, mammals All chordates exhibit four characteristics at some point in their lives: 1. hollow nerve cord that runs along the dorsal (back) part of the body; nerves branch from this nerve cord 2. notochord – long supporting rod that runs length of body just under nerve cord; most chordates have a notochord only when they are embryos 3. postanal tail – tail that extends past anus (at some point in life) 4. pharyngeal pouches – paired structures in throat region (aka pharynx) – in fish, slits develop that connect the pouches to the outside of the body (may develop into gills for gas exchange) Most chordates are vertebrates (except for few odd aquatic animals known an invertebrate chordates)

6 Check-in List the characteristics all animals have
Multicellular, heterotrophs, eukaryotes, no cell walls What characteristic do all invertebrates share? No backbone What characteristics do all chordates have sometime in their life cycle? Hollow nerve cord, notochord, postanal tail, pharyngeal pouches

7 Levels of Organization
Cells Tissues Organs Organ systems Organism Next 5 slides describe some features of animal body plans: levels of organization, body symmetry, differentiation of germ layers, formation of body cavities, and patterns of embryological development.

8 Types of Body Symmetry Asymmetry – no symmetry
Radial symmetry – body parts extend from central point Bilateral symmetry – two sides (mirror image) Anterior – front Posterior – back Dorsal – upper Ventral - lower Three types of symmetry that animals can have

9 Differentiation of Germ Layers
Cells of most animal embryos differentiate into: Endoderm – innermost layer Mesoderm – middle layer Ectoderm – outermost layer Endoderm – linings of digestive tract and much of respiratory system Mesoderm – muscles; much of circulatory, respiratory, and excretory systems Ectoderm – sense organs, nerves, outer layer of skin

10 Formation of a Body Cavity
Body cavity – fluid filled space between digestive tract and body wall Acoelomate – no body cavity Pseudocoelomate – body cavity partially lined with mesoderm Coelomate – body cavity lined with mesoderm Body cavity provides space in which internal organs can be suspended, and room for these organs to grow ex. Your stomach and digestive organs are suspended in your body cavity

11 Embryological Development
Zygote – fertilized egg Develops into blastula (hollow ball of cells) Blastopore – single opening to outside formed as blastula folds inward As zygote develops, becomes a blastula (hollow ball of cells like inflated balloon) As blastula develops, it folds in on itself (like holding balloon and pushing thumbs in toward center) Blatula becomes elongated structure with tube running in center (becomes digestive tract) Digestive tract has only one opening at first (blastopore) Efficient digestive sys needs two openings (mouth and anus) Protostome –organism in which blastopore becomes mouth Deuterostome –blastopore becomes anus

12 Check-in List the levels of organization
Cells  Tissues  Organs  Organ systems  Organisms What type of symmetry do each of the following have? Radial Bilateral Asymmetry Radial

13 Check-in Identify the sides of the animal that are labeled: dorsal
ventral posterior anterior

14 Check-in What germ layer is the outermost layer?
Ectoderm What germ layer makes up the linings of the digestive tract and respiratory system? Endoderm If an organism has a body cavity partially lined with mesoderm, what is it called? Pseudocoelomate

15 Check-in What is a fertilized egg called?
Zygote Organism in which blastopore becomes anus: Deuterostome What is an organism with a body cavity partially lined with mesoderm called? Pseudocoelomate

16 Chapter 26.1 Objectives Describe characteristics of invertebrate phyla.

17 Cladogram of Nonchordate Invertebrates
Cladogram – shows evolutionary relationships between organisms Nodes (red circles) – show where important traits evolved in the course of evolution

18 Phylum Porifera “Pore-bearer” Ex. Sponges No tissues or organ systems
Asymmetrical Filter feeders Simplest animals

19 Phylum Cnidaria “Nettle” or “Stinger”
Ex. Hydras, Jellyfish, Sea anemones, Corals Cells organized into tissues Radial symmetry Feed by stinging prey with nematocysts, mouth  gastrovascular cavity Aquatic, soft bodied, carnivorous, radial symmetrical animals with stinging tentacles arranged in circles around their mouths Simplest animals to have body symmetry and cells organized into tissues

20 Phylum Arthropoda Arthropods- “Jointed foot”
Ex. Insects, crustaceans, spiders Segmented body, exoskeleton of chitin, jointed appendages Segmented body – head and thorax or head/thorax/abdomen Exoskeleton that is shed as they grow (molting) A million species have been identified – more than 3x the number of all other animal species combined!

21 Nematoda - Roundworms Ex. pinworms Bilateral symmetry Tissue layers
Pseudocoelomate Digestive system with mouth and anus Molt (shed skin) as they grow Simplest organisms to have one-way gut (mouth and anus) Because they molt – they are considered to be more closely related to arthropods than other worms

22 Platyhelminthes - Flatworms
Ex. planarians, flukes, tapeworms Bilateral symmetry Three tissue layers Acoelomate Soft, unsegmented, flattened worms that have tissues and internal organ systems Simplest animals to have three germ layers, bilateral symmetry, and heads

23 Annelida – Segmented worms
Ex. earthworms, leeches, bristleworms Bilateral symmetry Tissue layers Coelomate

24 Annelida Systems Digestion- mouth and anus, pharynx
Circulation- closed system (blood contained in vessels) Respiration- some gills, skin Excretion- Nephridia, anus Nervous- brain and nerve cords Reproduction- Sexual: (most), separate sexes, hermaphrodites

25 Phylum Mollusca Mollusks
Ex. Gastropods (snails), Bivalves (clams), Cephalopods (squid) Internal or external shell Bilateral symmetry Tissue layers Coelomate Soft-bodied animals with internal or external shells Complex organ systems

26 Phylum Echinodermata Echinoderms- “Spiny skin”
Ex. Sea Stars, Sea Urchins, Sand Dollars Internal skeleton Water vascular system (tube feet) Radial symmetry Skin is stretched over an internal skeleton of calcium carbonate plates Water-vascular system – network of water-filled tubes that include suction-cuplike structures called tube feet (used for walking and gripping prey) Most adult echinoderms exhibit five part radial symmetry Deuterostomes – makes them more closely related to chordates than to other invertebrates (even though they have radial symmetry)

27 Chapter 26.2 Objectives Describe characteristics of chordate phyla.

28 Cladogram of Chordates
Evolutionary relationships of chordates Circles represent evolution of some important chordate adaptations

29 Nonvertebrate Chordates
Two invertebrate Urochordata: tunicates subphyla: Cephalochordata: lancelets Adult tunicates look like sponges and are filter feeders no body symmetry most display chordate features and bilateral symmetry only during larval stages Lancelets are fishlike animals with bilateral symmetry that live in salt water.

30 Jawless Fishes No true jaws or teeth Lack vertebrae
Skeleton made of cartilage Ex. Lampreys, hagfish Do have part of skull (why they are considered vertebrates) Have notochord as an adult Lampreys – top picture filter feeders as larvae; parasites as adults adults typically attach themselves to fish, scrap away skin with rasping tongue, and then such host’s tissues and body fluids called the “vampires of the sea” Hagfish pinkish grey wormlike body secrete lots of slime can tie their bodies into knots no image forming eyes – just light detecting sensors on their bodies feed on dead or dying animals using rasping tongue

31 Cartilaginous Fish Skeleton made of cartilage Paired fins
Most have tooth-like scales Ex. Sharks, rays, skates Paired fins allowed for greater control of body movement Tail fins and powerful muscles gave greater thrust Toothlike scales cover their bodies

32 Bony Fish Skeleton of true bone Paired fins, scales, gills
Swim bladder Ex. Perch, bass, flounder

33 Amphibians Means “double life” Undergo metamorphosis
Young: live in water and breathe with gills Adult: live on land and breathe with lungs and skin Undergo metamorphosis Dramatic change in body form Moist skin with mucous glands Lack scales and claws Ex. Frogs, toads, newts, salamanders

34 Amphibian Systems Digestive/Excretory: Nervous: Circulatory:
Developed: stomach, intestines, etc. Nervous: Developed: large eyesgreat sight Circulatory: Closed circulatory system Three chamber heart Reproductive: Most lay eggs without shells in water External Fertilization Respiratory: Gills when immature, lungs and skin when mature (skin must stay moist to function)

35 Reptiles Vertebrates with lungs Scaly skin
Leathery shelled amniotic eggs Ex. Lizards, snakes, turtles, crocodiles, dinosaurs Developed adaptations that allow them to live out of the water (do not rely on water for part of life cycle) well-developed lungs scaly skin to protect it from water loss amniotic eggs with leathery shell that allow them lay them on land (rather than in water)

36 Birds Warm-blooded Feathers Strong light-weight bones
Hard-shelled amniotic eggs Two scaly legs and wings as fore-limbs Ex. Hawk, eagle, penguin, ostrich, hummingbird, robin Warm-blooded reptiles (endothermic) – able to regulate own body temperature (only birds and mammals can do this – all other animals are cold-blooded (ectothermic) Descended from Archaeopteryx (dinosaur with feathers) Have strong but light-weight hollow bones to allow them to fly Also have air sacs in addition to lungs to allow for constant air-flow (great need for oxygen when flying)

37 Mammals Warm-blooded Feed young with milk from mammary glands
Hair or fur Breathe air Four-chamber heart Many groups of mammals- Insect-eating, Water-dwelling, Hoofed, Gnawing, etc.

38 Groups of Mammals Monotremes Marsupials Placental mammals:
Egg-laying mammals Ex. Platypus Marsupials Give birth to under-developed young Young develop in the pouch of the mother Ex. Kangaroo, koalas, possum Placental mammals: Give birth to young that have developed in the mother’s body Ex. Humans, Dogs, Mice

Download ppt "ANIMALS Chapters 25 and 26."

Similar presentations

Ads by Google