Chapter 32 An Introduction to Animal Diversity
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
2. Animal Cells Eukaryotic Nucleus with DNA Nuclear membrane bacterial cell animal cell
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
Animal Development Sexual reproduction (most) 1. Sperm + egg zygote (fertilized egg)
2. Cleavage of zygote blastula (hollow ball of ~ 100 cells) 3. Gastrulation process forms gastrula forms layers of embryonic tissue (germ layers)
Animal Development
Some animals Larva metamorphosis juvenile adult larva
Larva = immature, distinct from adult
Advanced animals mature into adult
I. History of Animals spans 0.5 billion years All animals share a common ancestor Paleozoic era (550 250 mya) Precambrian Algae, jellyfish Cambrian explosion ~520 mya Arthropods, chordates, echinoderms Mesozoic era (250 65 mya) Existing animal phyla evolved into new habitats Cenozoic era (65 mya present) Mammal herbivores and predators
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
Radial symmetry = sea anenome, jellyfish
Bilateral symmetry 2 sided Note: starfish larvae are bilateral
Tissues Tissue collection of specialized cells working together to perform a function Porifera (sponges) lack true tissue
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
Eumetazoans have true tissues
3 layers of embryonic tissue in blastula
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
1. True coelom develops from mesoderm Coelomates include Annelida, Arthrpodoa, Echinodermata Chordata
2. Pseudocoelomate Coelom forms partially from mesoderm and endoderm Nematoda roundworm
3. Acoelomate Lack a coelom Platyhelminthes flatworm
Protostome - blastopore becomes mouth
Deuterostome blastopore becomes anus (Chordata, Echinodermata)
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
Chapter 33 Invertebrates No backbone 95% of known animal species
CHOANOFLAGELLATES ([protista)
PHYLUM CALCARIA/SILICEA (polyphyletic) Sponges Suspension feeders Water w/food particles drawn through body Sessile adult Lack true tissues larva
PHYLUM Cnidaria Jellies, corals, hydras, anenomes Radial symmetry 2 germ layers Polyp and medusa forms Predators Tentacles with cnidocytes Medusa form is free swimming
Nerve net controls movement (no brain) Gastrovascular cavity with single opening
CLADE BILATERA Bilateral symmetry 3 embryonic germ layers Coelomates (most) Arose Cambrian explosion
PHYLUM PLATYHELMINTHES (flatworms) Acoelomate Lack a body cavity 3 germ layers brain Protostome Blastopore mouth Many parasitic
Planaria
Fluke causes schistosomiasi s in 200 million people
tapeworm
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
Chiton 8 plate shell, attached to rocks, use radula to scrape algae
Gastropods Torsion rotated visceral mass so that anus is above head
Bivalves No radula, no distinct head, hinged shell, adductor muscles, gills for feeding and gas exchange, excurrent siphon, suspension feeders
Cephalopods
Phylum Annelida (segmented worms) earthworms, sandworms, leeches Coleomate
Clade Bilatera Ecdysozoa Arthropods, nematodes DNA evidence External cuticle molts
PHYLUM NEMATODA = unsegmented roundworms Pseudocoelomate C. Elegans Trichinella
Coelomate Segmented body plan Jointed appendages Exoskeleton (protein, chitin) Molt Well developed sense organs Gas exchange Open circulatory system with hemolymph
Isopods are terrestrial
Bilatera Ecdysozoa Phylum ARTHROPODA Arachnids Horseshoe crab
Bilatera Ecdysozoa Phylum ARTHROPODA Myriapods Millipede, centipede
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
Deuterostome Blastopore develops into anus Coelomates
Bilatera Deuterostomia Phylum Echinodermata Sea stars, urchins, sea cucumber Water vascular system and tube feet for locomotion, feeding and gas exchange
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
Lancelet Branchiostomata, a cephalochordate 2. Dorsal hollow nerve cord (ectoderm) develops into brain, spinal cord (so this feature is retained in adults)
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
4. Post-anal tail
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
Craniates = chordates with a head Derived characters: Neural crest cells teeth, skull bones, dermis of face, some neurons
subphylum Craniates have a skull Hagfish Partial skull, invertebrate, no jaws, no scales Infraphylum Myxnidiae
Vertebrates have a backbone Vertebrae enclose spinal cord (subphylum Vertebrata) Infraphylum Vertebrata
Class Petromyzontiformes Jawless vertebrates: Lampreys Sucker mouth, predators, primitive, head but no skull, cartilage skeleton http://www.glfc.org/slft.htm
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)
Gnathostomes Have jaws 1. Chondricthyes fish have a cartilage skeleton Sharks, rays most carnivorous Class Chondricthyes
2. Ray-finned fishes Bony skeleton, bony scales Swim bladder for buoyancy Move gas from blood to bladder rise Class Osteoicthyes
3. Lobe-finned fish no swim bladder, lungs and gills lungfish
Lung of a lungfish, they also have gills. Can live out of water for months http://en.wikipedia.org/wiki/file:lungs_of_protopterus_dolloi.jpg
3. Tetrapods have limbs Evolved from a branch of lobefinned fish Neck vertebrae
Amphibians Salamaders, frogs, toads, salamanders, caecilians Require water for part of life External fertilization Class Amphibia
Amniotes are tetrapods that have a terrestrially adapted egg Reptiles, birds, mammals
Amniote egg has 4 specialized membranes Amnion membrane fluid bathes embryo Shock absorber Adaptation for terrestrial life
Reptiles and birds have shell to protect egg Prevents dehydration Mammalian egg develops in body Allows embryo to develop on land
Adaptations for terrestrial life Amniote egg Rib cage to ventilate lungs (frogs use throat)
reptiles Lizards, snakes, turtles, crocs, birds (!) Keratin scales to protect Injury Dehydration Internal fertilization
Most reptiles are ectothermic (obtain heat from environment) Birds are endothermic Internal fertilization
Birds, are they reptiles? Flight adaptation Wings, feathers Like crocs and some dinosaurs, are archosaurs
Mammals have mammary glands (females) Hair Endothermic Differentiated teeth
Monotremes lay eggs Marsupials give birth to embryo Eutherians have placenta
Xenarthra Tubulidentata Sirenia Carnivora Hyracoidea Lagomorpha Proboscidea Monotremata Marsupialia
Artiodactyl Cetacea Perissodactyla Chiroptera Rodentia Primates Eulipotyphl
Primates include monkeys and apes (also, lemurs, tarsiers)
Chapter 40 Principles of Animal Form and Function
Terms Anatomy form Physiology function Natural selection favors variations that best fit environment Variations are genetic and inherited
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
2. Exchange needs with the environment influence body plan More surface area = more exchange Amoeba Hydra Every cell has access to suitable environment
Surface to volume ratio must be high cells are small
Cell surfaces are bathed in interstitial fluid Bring nutrients, oxygen, rid of wastes
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
Epithelial tissue for linings Tightly packed cells Simple epithelium is 1 layer for secretion and absorption Stratified epithelium is multiple layers for protection
skin cervix
Apical surface faces a lumen or outside Basal surface attached to LUME underlying tissue N
Connective tissue Cells sparsely scattered Extracellular matrix of protein + Plasma (blood) Mineralized (bone) Gel (cartilage) CT also includes adipose CT, fibrous CT, loose CT
Muscle tissue Contraction
Nervous tissue Senses stimuli Transmit nerve impulses Brain, spinal cord, nerves
4. Coordination and Control = endocrine + nervous systems Endocrine system Gland produces hormone into bloodstream Target tissue responds Examples: adrenalin, insulin, estrogen Long lasting effects
Endocrine control Only cells with receptors respond
Nervous system =nerve impulses through nerves to: Other neuron Muscle Gland Fast
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
Homeostasis Steady internal state Ex. humans Body T Blood volume Blood ph Glucose concentration in blood
Negative feedback response lessens stimulus Stimulus receptor response body returns to set point Exercise nervous system sweating cool body T
Positive feedback Amplify the stimulus Ex. childbirth
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
Endothermic = birds, mammals Generate body heat via metabolism Can dump body heat by sweating, large ears etc. Staying in water helps dump heat
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!
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)
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
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
Chapter 41: Animal Nutrition
Terms Herbivore Carnivore Omnivore
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
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
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
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)
Stages of food processing Ingestion eating Digestion Break down food mechanically and chemically Absorption Nutrients absorbed into bloodstream cells Elimination Solid wastes
Comparative study 1. Some animals have a gastrovascular cavity one opening Cnidaria (hydra) Platyhelminthes flatworm (planaria)
Some have a complete digestive tract = alimentary canal = tube with compartments Annelida
2. Animals with teeth have dental adaptations Carnivore - tearing Herbivore - grinding Omnivore - unspecialized
3.Some animals have very long alimentary canal to digest vegetation (plant cell walls) Fibrous eucalyptus leaves
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
4-chambered stomach, eat grass rumen and reticulum (has protists and bacteria) chew cud abomasum swallow cud omassum
5. Some animals engage in corprophagy rabbits obtain nutrients from feces after bacteria in large intestine ferment
Chapter 46 Reproduction
Reproduction in animals Sexual reproduction Haploid gametes fuse zygote female gamete =? - large, non-motile male gamete =? - small, motile
Asexual reproduction 1. Fission = separation into 2 same sized individuals 2. Budding Cnidarians hydra, anemone, coral can also reproduce sexually under certain conditions
3. Fragmentation and regeneration piece breaks off, regenerates whole animal Sexual and asexual repro: Planaria (flatworm) Echinoderm
4. Parthenogenesis egg develops without fertilization Ex. some bee, lizard species Usually reproduces sexually
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
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
3. Hermaphroditism 1 individual with male and female reproductive system any two individuals can mate
4. Sex reversal individual changes sex during lifetime Ex. wrasse lives in group with one male. When male dies, the largest female becomes male
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
Chordata Vertebrata Amphibia
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
Survival of offspring in sexual reproduction Strategies 1. calcium/protein eggshell prevents dehydration Birds, reptiles, Mexican bearded lizard
2. Embryo develops internally Humans, kangaroos 3. Parental care Birds, mammals, (others)
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
Chapter 13 Meiosis
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)
sexual reproduction 2 parents give rise to genetically unique offspring
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
Autosomes = pairs 1 22 Arranged in homologous pairs Sex chromosomes = pair 23 XX = female XY = male
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?
Sperm + egg--- zygote fertilization Haploid diploid haploid diploid etc.
Animals BIO102
I. Interphase Note: nuclear membrane, chromatin, centrioles, microtubules Chromosomes (DNA) replicate to form sister chromatids
Sister chromatids identical #individual chromatids in a human cell once DNA has replicated? How many chromosomes?
II. Meiosis Cell division to produce unique haploid gametes Occurs in germ cells of plants, fungi, animals Maintains constant # of chromosomes in species
Stages of Meiosis Prophase I Nuclear envelope breaks down Chromosomes (sister chromatids) condense The diploid number of this cell is 6
Prophase I (continued) Spindle forms Centrioles migrate to poles Crossing over Non -sister chromatids exchange
Metaphase I Homologs line up on metaphase plate How many sister chromatids participate in each tetrad? How many chromosomes are present?
Anaphase I Homologs separate and move towards opposite poles Note: sister chromatids connected
Telophase I Each half of cell has a haploid set of chromosomes cytokinesis Division of cytoplasm 2 haploid daughter cells # chromosomes in each cell?
Meiosis I is called reduction division Each cell has 1 set of chromosomes
Meiosis II Prophase II spindle forms
Metaphase II Sister chromatids line up on metaphase plate Note: not identical microtubules attach to centrioles
Anaphase II Sister chromatids separate chromosomes move towards opposite poles Cohesions at centromere cleave
Telophase II Nuclei form around each haploid set cytokinesis 4 genetically unique haploid cells
Meiosis and genetic variation 1. crossing over 2. independent assortment 3. sexual reproduction
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
2. Independent assortment example: a male fruit fly has 8 chromosomes, 4 pairs, 1 set from mom, one from dad
Independent assortment 8 million combinations in a cell of 46 chromosomes
Overview of Meiosis