Animals Flashcards
Characteristics of animals
Eukaryotic
Heterotrohpic (via ingestion)
Lack cell wall (Proteins, like collagen support cell structure )
Composed of organized tissues
how do animals reproduce and develop
Diploid is dominant stage
Sperm and egg made directly through meiosis
Flagellated sperm
explain body plans symmetry
sessile, drifters or weak swimmers (eg jellyfish)
Sense enviroment equally from all sides
Different sides: dorsal (top), ventral (bottom), anterior (front), posterior (back)
Cephalization: brain/nervouse system concentrated in head
Coordinates more complex movements
Explain the body plans; tissues
Embryo forms germ layers,Blastula folds in on itself to create layers
Define ectoderm
forms outer covering of animal and central nervous system
Define endoderm
forms digestic tract (cavity) and organs
what is the role of the coelom
Cusions organs
Allows organs to grow
Allows organs to move independently of outer body
Allows animals without limbs to move
differences between deuterosomes and protosomes
protosomes have spiral clevage, determine clevae, a mass of mesoderm cells split to form coelom
Digetive tube, blastospore forms the mouth. Deuterosomes have radial cleavage, indeterminate cleavage,Coelom made of mesoderm cells bud from walls of the archenteron
Digetive tube; blostopore forms anus
two main features of the Lophotrochozoa clade
Lophophore: crown of tentacles for feeding
Trochophore: larval stage
what are the characteristics of Phylum mollusca
Slugs, snails, oysters, clams, octopuses, squids
Most produce shell of celcium carbonate
Ceolomate
Viseral mass: contains most internal organs
Mantel: cover internal organs, secretes shell (if present)
Foot: used for movment
what are errantians and sedentarians
Errantians: most marine, mobile, parapodia for locomotion
Sedentarians: less mobile, often elaborate gills/tentacles for filter feeding, includes leeches
how do earthworms reproduce
Asexual reproduction: fragmentation and regeneration
Sexual reproduction: align facing opposite direction, use musces to create slime tube, exchange sperm
what are the traits of Ecdysozoa
ecysis: moulting
Traits of Phylum Chordata
Bilaterally symmertrical
Deuterostomes
Mostly vertebrates
have notochord, nerve cord, pharyngeal slits/clefts, muscular post-anal tail
whats a notochord
fluid-filled cells surround by fibrous tissue
found in all embryos and some adults
Skeletel support
Jointed spinal cord develops
whats a muscular post-anal tail
Extends past anus
Made of skeletal elements and muscles
Helps propel many aquatic vertebrates
Reduced in many other species during embryo
characteristics of vertebrates
Skull and backbone (range from small pieces to enclosed spinal cord)
Complex nervous system
Greater gene complexity
hypothesis of Gnathostomes and evidence
Hypothesis: modification of skeletal ods that once supported pharyngeal slits and gills
Evidence: similar structure of bone/cartilage, during development same cells create jaws and gills as well as mucles to move them
how did bones and teeth evolve
Human skeleton = mineralized bone
Evolved through feeding mechanism, earliest mineralization in mouth
what is a tetrapods and what are their derived characteristics
tetrapods are animals with limbs
derived chacateristics: digits, neck, no gills (ears and glands)
Derived characteristics of mammals
Mammary glands
Hair or fur
Fat layer under skin
Diaphragm help ventilate
Long parental care
Differentiated teeth (canines, central incisor etc)
what are Monotremes
Platypus and spiny anteaters
Mammals that lay eggs, produce milk, lack nipples
what are Eutherians
Placental mammals (eg. Elephants)
Complete embryonic development in uterus
