Chapter 32. An Introduction to Animal Diversity

Transcription

1 Chapter 32 An Introduction to Animal Diversity

2 Animals are Multicellular, Heterotrophic, Eukaryotic, Metazoans 1. Heterotrophs Ingest organic materials (food) Living food, or dead Which of these heterotrophs is in Kingdom: Animalia? 400X magnification

3 2. Animal Cells Eukaryotic Nucleus with DNA Nuclear membrane bacterial cell animal cell

4 No cell wall (unlike plants and fungi) Collagen (structural protein) holds cells together Specialized cells include muscle and nerve Allows animals to coordinate activities and move

5 Animal Development Sexual reproduction (most) 1. Sperm + egg zygote (fertilized egg)

6 2. Cleavage of zygote blastula (hollow ball of ~ 100 cells) 3. Gastrulation process forms gastrula forms layers of embryonic tissue (germ layers)

7 Animal Development

8 Some animals Larva metamorphosis juvenile adult larva

9 Larva = immature, distinct from adult

10 Advanced animals mature into adult

11 I. History of Animals spans 0.5 billion years All animals share a common ancestor Paleozoic era ( mya) Precambrian Algae, jellyfish Cambrian explosion ~520 mya Arthropods, chordates, echinoderms Mesozoic era ( mya) Existing animal phyla evolved into new habitats Cenozoic era (65 mya present) Mammal herbivores and predators

12 II. Animals have body plans Body plan Set of morphological and developmental traits organized into a functioning body Symmetry No symmetry ex. Sponges = primitive animals

13 Radial symmetry = sea anenome, jellyfish

14 Bilateral symmetry 2 sided Note: starfish larvae are bilateral

15 Tissues Tissue collection of specialized cells working together to perform a function Porifera (sponges) lack true tissue

16 Eumetazoans have 2-3 embryonic tissue types Ectoderm Endoderm Mesoderm (in animals with bilateral symmetry) Cnidaria Corals have 2 embryonic tissues / Platyhelminthes flatworms have 3

17 Eumetazoans have true tissues

18 3 layers of embryonic tissue in blastula

19 Body Cavities Coelom = fluid filled space that separates digestive cavity from body wall In animals with 3 germ layers Not sponges, not cnidarians Cushions suspended organs Allows organs to move and grow independent of body wall

20 1. True coelom develops from mesoderm Coelomates include Annelida, Arthrpodoa, Echinodermata Chordata

21 2. Pseudocoelomate Coelom forms partially from mesoderm and endoderm Nematoda roundworm

22 3. Acoelomate Lack a coelom Platyhelminthes flatworm

23 Protostome - blastopore becomes mouth

24 Deuterostome blastopore becomes anus (Chordata, Echinodermata)

25 Summary 1. All metazoans (animals) share a common ancestor 2. Sponges are the most primitive 3. Eumetazoans have true tissues 4. Most animals are in Bilatera Bilateral symmetry and 3 germ layers 5. Chordates and echinoderms are deuterostomes

26 Chapter 33 Invertebrates No backbone 95% of known animal species

27 CHOANOFLAGELLATES ([protista)

28 PHYLUM CALCARIA/SILICEA (polyphyletic) Sponges Suspension feeders Water w/food particles drawn through body Sessile adult Lack true tissues larva

29 PHYLUM Cnidaria Jellies, corals, hydras, anenomes Radial symmetry 2 germ layers Polyp and medusa forms Predators Tentacles with cnidocytes Medusa form is free swimming

30 Nerve net controls movement (no brain) Gastrovascular cavity with single opening

31 CLADE BILATERA Bilateral symmetry 3 embryonic germ layers Coelomates (most) Arose Cambrian explosion

32 PHYLUM PLATYHELMINTHES (flatworms) Acoelomate Lack a body cavity 3 germ layers brain Protostome Blastopore mouth Many parasitic

33 Planaria

34 Fluke causes schistosomiasi s in 200 million people

35 tapeworm

36 PHYLUM MOLLUSCa Chitins, snails, slugs, abalone, clams, octopi, squid Coelomates 3 main body parts Muscular foot- for movement Mantle may secrete shell Visceral mass has organs Open circulatory system Protostome Blastopore mouth

37 Chiton 8 plate shell, attached to rocks, use radula to scrape algae

38 Gastropods Torsion rotated visceral mass so that anus is above head

39 Bivalves No radula, no distinct head, hinged shell, adductor muscles, gills for feeding and gas exchange, excurrent siphon, suspension feeders

40 Cephalopods

41 Phylum Annelida (segmented worms) earthworms, sandworms, leeches Coleomate

42 Clade Bilatera Ecdysozoa Arthropods, nematodes DNA evidence External cuticle molts

43 PHYLUM NEMATODA = unsegmented roundworms Pseudocoelomate C. Elegans Trichinella

44 Coelomate Segmented body plan Jointed appendages Exoskeleton (protein, chitin) Molt Well developed sense organs Gas exchange Open circulatory system with hemolymph

45 Isopods are terrestrial

46 Bilatera Ecdysozoa Phylum ARTHROPODA Arachnids Horseshoe crab

47 Bilatera Ecdysozoa Phylum ARTHROPODA Myriapods Millipede, centipede

48 Insects have 3 pairs of legs, some have wings, some undergo metamorphosis Sexual reproduction, some are pests, some transmit disease, Bilatera Ecdysozoa Phylum ARTHROPODA Insects Subphylum Hexopoda

49 Deuterostome Blastopore develops into anus Coelomates

50 Bilatera Deuterostomia Phylum Echinodermata Sea stars, urchins, sea cucumber Water vascular system and tube feet for locomotion, feeding and gas exchange

51 Phylum Chordata Chordates have 4 shared embryonic characteristics 1. Notochord (mesodermal cells) Flexible rod between gut and nerve cord Skeletal support In vertebrates bony skeleton in humans persists as intervertebral discs Lost in most adult chordates Tunicate larva, sea squirt

52 Lancelet Branchiostomata, a cephalochordate 2. Dorsal hollow nerve cord (ectoderm) develops into brain, spinal cord (so this feature is retained in adults)

53 3. Pharyngeal clefts pouches and grooves allow water to enter/exit without passing through digestive tract develop into gill slits for feeding, gas exchange Role in ear, neck development in tetrapods amphioxus fish human

54 4. Post-anal tail

55 Invertebrate chordates No vertebral column, notochord found in adults Lancelets and tunicates Lancelet, eaten in Asia Retain 4 characteristics as adults Sea squirt 3,000 species retain the gills but larvae have all 4

56 Craniates = chordates with a head Derived characters: Neural crest cells teeth, skull bones, dermis of face, some neurons

57 subphylum Craniates have a skull Hagfish Partial skull, invertebrate, no jaws, no scales Infraphylum Myxnidiae

58 Vertebrates have a backbone Vertebrae enclose spinal cord (subphylum Vertebrata) Infraphylum Vertebrata

59 Class Petromyzontiformes Jawless vertebrates: Lampreys Sucker mouth, predators, primitive, head but no skull, cartilage skeleton

60 Fishes are aquatic, gill-breathing vertebrates that usually have fins and skin covered with scales. (lamprey and hagfish are fish, but do not have scales)

61 Gnathostomes Have jaws 1. Chondricthyes fish have a cartilage skeleton Sharks, rays most carnivorous Class Chondricthyes

62 2. Ray-finned fishes Bony skeleton, bony scales Swim bladder for buoyancy Move gas from blood to bladder rise Class Osteoicthyes

63 3. Lobe-finned fish no swim bladder, lungs and gills lungfish

64 Lung of a lungfish, they also have gills. Can live out of water for months

65 3. Tetrapods have limbs Evolved from a branch of lobefinned fish Neck vertebrae

66 Amphibians Salamaders, frogs, toads, salamanders, caecilians Require water for part of life External fertilization Class Amphibia

67 Amniotes are tetrapods that have a terrestrially adapted egg Reptiles, birds, mammals

68 Amniote egg has 4 specialized membranes Amnion membrane fluid bathes embryo Shock absorber Adaptation for terrestrial life

69 Reptiles and birds have shell to protect egg Prevents dehydration Mammalian egg develops in body Allows embryo to develop on land

70 Adaptations for terrestrial life Amniote egg Rib cage to ventilate lungs (frogs use throat)

71 reptiles Lizards, snakes, turtles, crocs, birds (!) Keratin scales to protect Injury Dehydration Internal fertilization

72 Most reptiles are ectothermic (obtain heat from environment) Birds are endothermic Internal fertilization

73 Birds, are they reptiles? Flight adaptation Wings, feathers Like crocs and some dinosaurs, are archosaurs

74 Mammals have mammary glands (females) Hair Endothermic Differentiated teeth

75 Monotremes lay eggs Marsupials give birth to embryo Eutherians have placenta

76 Xenarthra Tubulidentata Sirenia Carnivora Hyracoidea Lagomorpha Proboscidea Monotremata Marsupialia

77 Artiodactyl Cetacea Perissodactyla Chiroptera Rodentia Primates Eulipotyphl

78 Primates include monkeys and apes (also, lemurs, tarsiers)

79 Chapter 40 Principles of Animal Form and Function

80 Terms Anatomy form Physiology function Natural selection favors variations that best fit environment Variations are genetic and inherited

81 I. Animal form and function are correlated at all levels of organization 1. Physical constraints on size and shape 50 mph Shape example: in water, bump on surface of animal causes drag. Tapered body to swim fast to overcome drag Convergent evolution

82 2. Exchange needs with the environment influence body plan More surface area = more exchange Amoeba Hydra Every cell has access to suitable environment

83 Surface to volume ratio must be high cells are small

84 Cell surfaces are bathed in interstitial fluid Bring nutrients, oxygen, rid of wastes

85 3. Hierarchical organization Cell tissue organ organ system organism 4 categories of animal tissues Epithelial tissue lines organs and cavities, composes glands Connective tissue binds and supports Muscular tissue for movement Nervous tissue for communication

86 Epithelial tissue for linings Tightly packed cells Simple epithelium is 1 layer for secretion and absorption Stratified epithelium is multiple layers for protection

87 skin cervix

88 Apical surface faces a lumen or outside Basal surface attached to LUME underlying tissue N

89 Connective tissue Cells sparsely scattered Extracellular matrix of protein + Plasma (blood) Mineralized (bone) Gel (cartilage) CT also includes adipose CT, fibrous CT, loose CT

90 Muscle tissue Contraction

91 Nervous tissue Senses stimuli Transmit nerve impulses Brain, spinal cord, nerves

92 4. Coordination and Control = endocrine + nervous systems Endocrine system Gland produces hormone into bloodstream Target tissue responds Examples: adrenalin, insulin, estrogen Long lasting effects

93 Endocrine control Only cells with receptors respond

94 Nervous system =nerve impulses through nerves to: Other neuron Muscle Gland Fast

95 II. Feedback Control Loops Maintain Homeostasis Regulator animal Ex. river otter s body temp is constant even when water T changes Conformer animal Ex. Bass (fish) conforms its internal T to T of the lake

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97 Homeostasis Steady internal state Ex. humans Body T Blood volume Blood ph Glucose concentration in blood

98 Negative feedback response lessens stimulus Stimulus receptor response body returns to set point Exercise nervous system sweating cool body T

99 Positive feedback Amplify the stimulus Ex. childbirth

100 III. Thermoregulation Critical for homeostasis body enzymes work at certain temperatures each animal has optimal T range Heat loss in water is about 27 times faster than in air at the same temperature

101 Endothermic = birds, mammals Generate body heat via metabolism Can dump body heat by sweating, large ears etc. Staying in water helps dump heat

102 Ectothermic = fish, lizards, snakes, frogs Heat source environmental Behavioral adaptations Note: Sea lion obtain heat by raising flippers out of the water -technically, that s ectothermic!

103 Strategies to regulate heat gain and loss 1. Integumentary system adaptations (skin) Insulation Fat Raise fur or feathers to trap air Secrete oil on feathers to repel water Cooling by sweat, panting (evaporative)

104 2. Circulatory system adaptations Blood vessel dilation at skin to cool body Blood vessel constriction to warm body Counter current exchange in some animals Blood in artery warms blood in vein Reduces heat loss

105 3. Behavioral adaptations Amphibians seek moist, warm environment Reptiles move around during the day Insects orient toward sun 4. Thermogenesis = heat production ex. shivering, movement 5. Acclimitization thicker coat, enzyme expression Ex. arctic flounder/antifreeze

106 Chapter 41: Animal Nutrition

107 Terms Herbivore Carnivore Omnivore

108 Diet must supply energy and essential nutrients Essential nutrients 1. Essential amino acids (humans require 8) tryptophan, lysine, methionine, valine, leucine, isoleucine, threonine, phenylalanine Need all 20 to synthesize proteins Complete protein contains all essential aa ex. meat, eggs Incomplete protein eat with others to obtain all aa

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110 2. Essential fatty acids Omega- 3 and omega-6 (alphalinoleic and linoleic) Seeds, grains, vegetables 3. Vitamins 13 organic molecules required in small amounts (humans) Ex. A, Bs, C, D, E, K

111 Richard Smithells of the Univ. of Leeds examined the effect of prenatal vitamins on neural tube defects in their infants. All women in the study had a previous child with a neural tube defect. Half the women took vitamins at least 4 months before trying to get pregnant. The other half either were already pregnant or declined the vitamins. The number of neural tube defects in the infants were counted

112 4. Minerals are inorganic, require small amounts Ca, Fe, Na, Zn, Mg, Cu, S, Cl, P Calories from fats, protein, carbohydrates Water (not a nutrient)

113 Stages of food processing Ingestion eating Digestion Break down food mechanically and chemically Absorption Nutrients absorbed into bloodstream cells Elimination Solid wastes

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115 Comparative study 1. Some animals have a gastrovascular cavity one opening Cnidaria (hydra) Platyhelminthes flatworm (planaria)

116 Some have a complete digestive tract = alimentary canal = tube with compartments Annelida

117 2. Animals with teeth have dental adaptations Carnivore - tearing Herbivore - grinding Omnivore - unspecialized

118 3.Some animals have very long alimentary canal to digest vegetation (plant cell walls) Fibrous eucalyptus leaves

119 4. Some animals have mutualistic relationships with other animals for digestion Ex. Ruminants have bacteria to digest cellulose sugar for both bacteria and cow bacteria use sugar to produce vitamins

120 4-chambered stomach, eat grass rumen and reticulum (has protists and bacteria) chew cud abomasum swallow cud omassum

121 5. Some animals engage in corprophagy rabbits obtain nutrients from feces after bacteria in large intestine ferment

122 Chapter 46 Reproduction

123 Reproduction in animals Sexual reproduction Haploid gametes fuse zygote female gamete =? - large, non-motile male gamete =? - small, motile

124 Asexual reproduction 1. Fission = separation into 2 same sized individuals 2. Budding Cnidarians hydra, anemone, coral can also reproduce sexually under certain conditions

125 3. Fragmentation and regeneration piece breaks off, regenerates whole animal Sexual and asexual repro: Planaria (flatworm) Echinoderm

126 4. Parthenogenesis egg develops without fertilization Ex. some bee, lizard species Usually reproduces sexually

127 Reproductive Cycles 1. Ovulation seasonal release mature eggs, controlled by hormones promotes offspring survival ex. sheep Or, monthly, as in humans Ovulate late fall 5 mos lamb in spring

128 Ex. Daphnia 2. Two egg types for fertilization (response to environmental stress) for parthenogenesis (summer) Crustacean (Phylum Arthropoda) When summer is over, some of the eggs develop into the small males which fertilize eggs

129 3. Hermaphroditism 1 individual with male and female reproductive system any two individuals can mate

130 4. Sex reversal individual changes sex during lifetime Ex. wrasse lives in group with one male. When male dies, the largest female becomes male

131 Fertilization = sperm + egg 1. External fertilization Spawning Female releases eggs, males sperm into environment Requires moist environment Some animals do not require physical contact Controlled by cues Environmental temperature, day length, lunar Courtship Large number offspring, few survive

132 Chordata Vertebrata Amphibia

133 2. Internal fertilization Adaptation for dry environment Deliver sperm to egg internally Require copulation Mates attracted by pheromones Chemicals released into environment Fewer offspring, more resources invested

134 Survival of offspring in sexual reproduction Strategies 1. calcium/protein eggshell prevents dehydration Birds, reptiles, Mexican bearded lizard

135 2. Embryo develops internally Humans, kangaroos 3. Parental care Birds, mammals, (others)

136 Gamete production Gonads Organs that produce gametes May be indistinct with gametes shed Ex. Annelida May have testes and ovaries to produce sperm, egg Spermatogenesis Oogenesis

137 Chapter 13 Meiosis

138 Chapter 13 Meiosis Terms Heredity Transmission of traits to offspring Variation Genetic variation in population Genetics Study of heredity Genes DNA coded information for protein Gametes Sperm and egg (and spores)

139 sexual reproduction 2 parents give rise to genetically unique offspring

140 Sexual Life Cycles Life cycle from conception to production of offspring Somatic cells (body cells) 46 chromosomes 23 homologous pairs 2n (diploid) = 46 Same size Same gene loci Same centromere position One set from mother, one set from father

141 Autosomes = pairs 1 22 Arranged in homologous pairs Sex chromosomes = pair 23 XX = female XY = male

142 Germ line cells ovary/testes 1n (haploid) = 23 Fertilization 1n + 1n = 2n Ex. Fruit fly egg has 4 chromosomes (1n). How many chromosomes in a sperm? A fly larval cell? An adult somatic cell?

143 Sperm + egg--- zygote fertilization Haploid diploid haploid diploid etc.

144 Animals BIO102

145 I. Interphase Note: nuclear membrane, chromatin, centrioles, microtubules Chromosomes (DNA) replicate to form sister chromatids

146 Sister chromatids identical #individual chromatids in a human cell once DNA has replicated? How many chromosomes?

147 II. Meiosis Cell division to produce unique haploid gametes Occurs in germ cells of plants, fungi, animals Maintains constant # of chromosomes in species

148 Stages of Meiosis Prophase I Nuclear envelope breaks down Chromosomes (sister chromatids) condense The diploid number of this cell is 6

149 Prophase I (continued) Spindle forms Centrioles migrate to poles Crossing over Non -sister chromatids exchange

150 Metaphase I Homologs line up on metaphase plate How many sister chromatids participate in each tetrad? How many chromosomes are present?

151 Anaphase I Homologs separate and move towards opposite poles Note: sister chromatids connected

152 Telophase I Each half of cell has a haploid set of chromosomes cytokinesis Division of cytoplasm 2 haploid daughter cells # chromosomes in each cell?

153 Meiosis I is called reduction division Each cell has 1 set of chromosomes

154 Meiosis II Prophase II spindle forms

155 Metaphase II Sister chromatids line up on metaphase plate Note: not identical microtubules attach to centrioles

156 Anaphase II Sister chromatids separate chromosomes move towards opposite poles Cohesions at centromere cleave

157 Telophase II Nuclei form around each haploid set cytokinesis 4 genetically unique haploid cells

158 Meiosis and genetic variation 1. crossing over 2. independent assortment 3. sexual reproduction

159 1. Crossing over during prophase I Synapsis Synaptonemal complex Zips up homologous chromosomes (sister chromatids) Crossing over Between non-sister chromatids Chiasmata X observed after crossing over unique gametes due to recombinant chromosomes

160 2. Independent assortment example: a male fruit fly has 8 chromosomes, 4 pairs, 1 set from mom, one from dad

161 Independent assortment 8 million combinations in a cell of 46 chromosomes

162 Overview of Meiosis