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66 Cards in this Set

  • Front
  • Back
what is an animal?
-heterotrophs that obtains nutrients by ingestion
- multi cellular eukaryote
- most are diploid
- most have muscles for movement
- most have nerve cells to conduct impulses
- some new development genes for animals
earliest fossils?
~600 million years ago (cambrian period)
during cambrian period 545 years ago, there was an explosion of evolution in a ten year period
reasons for cambrian explosion of evolution?
-change in atmosphere
-predator prey relationships
-genetic changes in HOX genes
sponges (porifera)
- about 9,000 species
- radial symmetry
- suspension feeders
- radial symmetry
- incomplete digestive system
- digestion
- circulation
- physical support and movement
- cnidocytes (stinging cells)
bilateral symmetry
- anterior and posterior end
- dorsal and ventral surfaces
- head is prominent part of animal
-houses main sensory organs (eyes, brain, mouth)
-nervous system (head and sensory organs branching throughout body)
- active and travel headfirst through environment
-bilateral symmetry
-complete digestive tract
-freeliving- planaria
-flukes- parasites- schistosoma
-tapeworms- parasitic- no digestive tract, absorb nutrients directly through body. each segment has male and female parts for reproduc.
body cavity
-psuedocoleumn- not completely lined by tissues from the mesoderm
-coleumn- completely lined by tissues from the mesoderm- connect and suspend organs and digestive tract from body wall.
-advantages: hydroskeleton provides structure for muscles to exert force for movement. cushions organs. may circulate oxygen and nutrients and assist in waste disposal.
-complete digestive tract
- psuedocolumn
- most numerous in number of species and individuals.
- C.Elegans Trichinella Spiralis
-150,000 known species
- foot, visceral mass, mantle, radula
- true coleumn
- circulatory system
Gastropods (subgroup of Mollusk)
-lack a mantle
-shelves divided into two halves
-built for speed and agility
- no shell, internal shell or, small shell
segmented body
-subdivision of body along length into series of repeated parts
-allows great flexibility and mobility
-segmented body
-about 15,000 species
-examples: earthworms, leaches, polychaetes
-means jointed appendages
-about 1 million species
-about 10^18 individuals
-exoskeleton -hard external skeleton: made up of protein and chitin, for protection, also points of attachment for muscles.
-requires molting for changing of exoskeleton
-distinct segments- head, thorax, abdomen (head and thorax may combine to make a cephathorax)
-sea stars, sand dollars, and sea urchins
-all marine
-no segments
-most radial symmetrical (have bilateral larvae stage that differentiates them from cnidarians)
-water vascular system
-can regenerate lost limbs
-four distiguishing features- dorsal hollow nerve chord, notochord, pharengial slits, post anal tail.
-invertebrate chordates- tunicates, lancelets
- vertebrates
-skull and backbone
-most have hinged jaws (except agnatians)
-cartilagenous fishes
-sharks, rays and skates
-flexible skeletons
-most are predators
-lateral line system (nerves running along side of body that sense pressure changes in water)
-bony fishes
-lateral line system
-keen sense of smell
-excellent eyesight
-operculum (protective flap that covers gills)
-swim bladder- keeps bouyant
-most are ray finned fishes
-lobe finned fish- coelacanth
-lungfishes- inhabit stagnant waters, gulp air into lungs connected to pharnyx
-mixture of aquatic and terrestrial life
-adults can live on land, but eggs would dry out
-about 4,800 species
-first terrestrial vertebrates
-transition from fish about 400MYA
-dominated in Carboniferous forests
-about 6500 species
-lizards, snakes, turtles, crocidiles
-scaly skin (keratin waterproofs)
-amniotic eggs (nourished by yolk)
-dinosaurs- dominated 200MYA, fade 70MYA, mass extinct 65MYA
-8600 species
-adaptations for flight:
-no teeth
-tail supported by a few vertebrate
-hollow feathers
-bones have honeycomb structure for light strength
-flight feathers shape wings into airfoil
-large breast muscles tied to a keel like breastbone

-high metabolism
-efficient circulatory system
-best vision of all vertebrates
-relatively large brains
-evolved from reptiles 220MYA
-became more diverse after dinosaurs
-most terrestrial
-1,000 species fly, 80 swim.
-hair, mammary glands
monotreme(division of mammal)
-egg laying mammals (duck billed platypus)
marsupials (division of mammals)
-brief gestation
-born tiny
-complete development attached to mother's nipple.
-developing young usually protected in external pouch.
- nearly all in C. S. America, New Zealand and Australia
-95% of 4500 species of mammals
-strong connection between mother and young through placenta
earliest primates?
2 groups of primates
-prosimians-lemurs and loris
-anthropoids (humans and monkeys)
-may have evolved from prosimians 45 MYA
old world monkeys
-some arboreal and some ground dwelling
-nostrils close together, some with hard seat pad.
new world monkeys
-all arboreal
-nostrils wide open and farther apart
-many with prehensile tail
humans probably diverged with chimpanzees 5-7MYA
-closest relatives of humans
-no tail
-forelimbs longer than hindlimbs
-chiefly vegetarians (chimpanzees eat insects and small vertebrates)
-larger brains relative to monkeys
-biochemical evidence that chimpanzee and gorilla more closely related to humans than other apes
-human DNA differs from chimpanzee DNA by only 3%
-only entirely arboreal apes
-only apes that are monogamous
-shy solitary species from Borneo and Sumatra
-largest living arboreal mammal
-largest of all primate species
-walk on knuckles
chimpanzee and bonobos
-knuckle walkers
-make and use simple tools
-raid other groups of their same species
humans 5major differences
-increased brain size (3X larger than ancestors 6MYA)
-shorter jaws, flatter faces
-bipedal posture
-reduced size between sexes
-key changes in family structure
upright posture origins
hominids in forests which may have made entering the savannah easier.
enlargement of human brain?
homo habilus
-existed for about a million years with Australopithecines
-found simple tools useful
-scavenging, gathering and hunting
-may have given rise to homo erectus
homo erectus
-taller than habilus and larger brain
-males about 1.2x size of females
-may have been start of monogamy
-first to spread out of africa to asia and europe about 1.8 MYA
-lived in huts, wore clothes from skins
-gave rise to homo sapiens
-europe (200,000 to 40,000 years ago)
-short and stocky, heavily muscled
-skilled tool makers
-participated in rituals that required abstract thought
homo sapiens origins
-may have originated 100,000 years ago
-second wave of H.Erectus led to H.Sapiens
highlights of h. sapiens evolution
-evolution of erect stance (remodeling of foot, pelvis and vertebral column)
-enlargement of brain
-prolonged prenatal care
1st major stage of cultural evolution
-scavenging main way of accessing food
-hunting not feasible until 50,000 years ago with invent of tools
-may have caused extinction of large numbers of predators and prey
-started divisions of labor and semi permanent living establishments
2nd major stage of cultural evolution
-10,000-15,000 years ago
-more intensive agricuture, populations grew
-permanent settlements and first cities arose
-specialization of labor
3rd major stage of cultural evolution
-industrial revolution in Europe in 18th centur
-mediciines reduced death rate
-fewer needed for farming, moved to cities
-food and drink are swallowed- swallowing causes reflex that closes the trachea and opens the esophagus- food moves down with peristalsis- stomach secretes gastric juices that start digestion-partially digested food moves into small intestine- what passes through small intestine goes into colon and rectum- what was absorbed by stomach and s. intest moves into liver
gastric juice components
mucus, enzymes and strong acids.
small intestine
-6.5 meters long, but only 2.5cm in diameter
-most nutrients are absorbed in small intestine
-large surface area due to many folds (villi) and projects at the tip of epipethelial cells (microvilli)
-blood from small intestine goes into liver
-stores glucose as glycogen and maintains glucose/blood concentration
-detoxifies toxins
ethanol digestion
-some ethanol can be absorbed through stomach lining (ethanol is bipolar)
-in stomach are enzymes that break down alcohol
-blood from stomach goes to liver
-ethanol that dissolves into the epithelial cells is also broken down by detoxifying enzymes.
-ethanol that wasn't broken down in epethilial cells and stomach is broken down here
what affects BAC?
-amount of alcohol
-activity of enzymes in epethelial layer and liver
-food consumed
-gender (women have less body water and lower activity of ADH)
effects of alcohol consumption?
-fat and protein accumulation in liver leading to hepatocytes that can lead to necrosis and fibrosis
-enhanced chance of cancer
-reduceds quality of sleep
-memory impairment
-brain shrinkage
-alters reproductive hormones
-lower calcium levels
muscle contraction and movement
signal from brain passes down spinal cord to nuerons with axons that pass out of the spinal cord that attach to muscle fibers (nueromuscular junctions)-triggers release of NT (acetylcoline)
trigger salivation
chemicals in the air are taken in through the nose and mixed with mucus in the back of the nose- chemicals bind to cilia that penetrate mucus layer- changes pattern of nerve impulses which the brain interprets as a smell
-salivary glands secrete saliva at the sight or smell of food (1L/day)
-slippery glycoprotein that protects inside of mouth
-buffered to nuetralize food acids
-antibacterial agents that kill bacteria
-contains digestive enzymes
taste buds
-group of sensory cells with proteins in their membranes that interact with chemicals in foods.
-stimulated by bright light and distinguish color
-6 million in retina
-extremely sensitive to light and enable us to see in dim light
-about 125 million in retina
-found primarily in retina, completely absent from fovea
color blindness
-due to a defeciency in cones
-generally small nitrogen containing molecules