Study Guides (380,000)
CA (150,000)
McMaster (9,000)
BIOLOGY (500)
Midterm

BIOLOGY 3MM3 Study Guide - Midterm Guide: Disaccharide, Thaliacea, Radiolaria


Department
Biology
Course Code
BIOLOGY 3MM3
Professor
Michael O' Donnell
Study Guide
Midterm

This preview shows pages 1-2. to view the full 8 pages of the document.
Phylogeny: hierarchic relationships between groups (taxa) of animals
Phylogenetic systematics/cladistics: discovery and depiction of phylogeny
Syncytia: barriers between cells broken; nuclei scattered
3 Major Theories of Classification
1. Evolutionary classification: uses both ancestry (i.e. fossil evidence) and degrees of divergence from ancestral form;
subjective (i.e. which homologies are most important); convergence — separate paths to final state (ex. octopus and
vertebrate eyes; acoelomate condition may have arisen from coelomates)
-homology: traits sharing common evolutionary origin
-coelom: fluid filled cavity formed within the mesoderm; a second body cavity other than the gut (endoderm)
2. Phenetics: anatomical and biochemical similarity; numerical taxonomy; ignores homologies and convergence
3. Cladistics: based on recency of common descent inferred from synapomorphies
-synapomorphy: homology based on recent shared ancestry; derived characteristics or trait shared by two or more taxa
(morphological, embryological, molecular); portrays kinship relationships in a phylogenetic tree (cladogram) — each line
represents a shared derived characteristic
Kingdom Protozoa: unicellular, lacking collagen and chitinous cell walls; non-photosynthetic in the primitive condition;
comparative with our cells - multifunctional, complex and different
CILIOPHORA (cilia bearing) — ciliates: external ciliation and complex infraciliature; free-living (motile or sessile); cytostome
(position, structure and ciliation of oral region); highest degree of sub cellular specialization; dimorphic nuclei (macro-
housekeeping and micronucleus- reproduction) ex. paramecium, vorticella, didinium
SARCOMASTIGOPHORA (flesh whip bearing) — sarcodines: free-living/parasitic; monomorphic nucleus; pseudopodia
(cytoplasmic extensions of the body) include naked forms (amoeba) and with a protective shell/test (radiolarians and
foraminiferans)
-Mastigophorates — flagellates: often bear external hairlike projections (mastigonemes)
-phytoflagellates (grouping of convenience) contain chlorophyll (ex. euglena, volvox, chlamydomonas, dinoflagellates - red
tide)
-zooflagellates: include choanoflagellates — single flagellum extends for part of its length through a collar made by closely
packed cytoplasmic strands - microvilli (ex. proterospongia); free-living or parasitic — trypanosomes cause sleeping
sickness in Africa; Chaga’s disease by triatomid bugs and giardia
APICOMPLEXA: spore-producing parasitic protozoa with apical complex (which may help the parasite enter the host cell) ex.
plasmodium (malaria)
Kingdom Metazoa: multicellular
PORIFERA (pore bearing) — sponges: microvillar collars around flagella with units arising from either single cells or syncytia;
aquiferous system, spicules (structural support - made of silica/calcium carbonate); body is covered with pores in which water
flows one-way into complex channels; inner chambers are lined with choanocytes (collar cells) in which a flagellum is surrounded
by a ring-like comb, the beating of the flagellum draws water through the comb
CNIDARIA (a stinging thread/hollow gut) — jellyfish, corals, sea anemones: secretion of complex intracellular organelles -
cnidae (nematocysts); planula larvae in the life cycle; two body forms: polyp (sessile) and medusa (free-swimming)
-Scyphozoa (cup animals): asexual reproduction by strobilation
-Cubozoa (cube animals): medusa with boxlike body; rhopalia bear complex, lensed eyes
-Hydrozoa (water animals): characterized by generally greater presentation of the polyp morph in the life cycle; gastrodermal
tissue lacks nematocysts and no cells found within the mesoglea
-Anthozoa (flower animals): absence (loss?) of a medusa state; absence (loss?) of operculum and cnidocil; mitochondrial
DNA is circular; presence of ciliated grove (siphonoglyph) in the pharyngeal wall partitioned by distant sheets of tissues
(mesenteries/septa)
Hexacorallia (six): possess tentacles around the mouth opening (multiple of 6) and 6 pairs of primary mesenteries; one
pair of siphonoglyphs is associated with the pharynx; many species are solitary
Octocorallia (eight): polyps bear 8 tentacles and are subdivided by 8 complete mesenteries
CTENOPHORA (comb bearing) — comb jellies: plates of fused cilia arranged in rows; adhesive pre-capturing cells
(colloblasts)
Bilateral symmetry: left/right and front/back; anterior gets more sensory information; chemical cues and mechanical information
Cephalization: brain/NS development; sensory system/neurons at the front end
Triploblastic: 3 tissue layers (germ cell layers)
-Ectoderm: outermost; differentiates to form the NS and the epidermis
-Mesoderm: middle layer; differentiates to form bone, muscle, connective tissue

Only pages 1-2 are available for preview. Some parts have been intentionally blurred.

-Endoderm: inner layer; forms the epithelial lining of the alimentary canal (except part of mouth, pharynx and rectum)
PROTOSTOMES VS. DEUTEROSTOMES
PROTOSTOMES
PLATYHELMINTHES (flatworm) — flatworms: acoelomate, triploblastic, bilaterally symmetrical
-Turbellaria: all “turbellarian” flatworms placed within a single class; in all other flatworm groups (Cestoda, Monogenea,
Digenea, Aspidogasterea) the larval epidermis is replaced at metamorphosis by a living, nonciliated, syncytial tegument — a
likely homology suggesting that parasitism arose once in an ancestor to all of these classes and they therefore be groups
with a single clade — the Neodermata (new skin)
-Cestoda: small anterior hook attachment organ (scolex); division of body into segments (proglottids) arising from anterior
end, behind scolex; absence (loss) of digestive tract; mimics lining of GI tract, absorption over body surface; proglottid
production consistent with the health of the host
-Monogenea: posterior attachment organ (haptor) including sucker and complex attachment hooks and sclerites; larva
(oncomiracidium) bearing 3 bands of cilia and 1-2 pairs of eyes; normally found on gills of fish
-Trematoda: outer body layer of adults is unciliated syncytial tegument — more closely resembles that of a turbellarian; mouth
opening and a blind-ended digestive tract that is bilobed; non-segmented body; smaller male lives in groove of larger female
NEMERTEA: muscular eversible proboscis housed in a fluid-filled, schizocoelous cavity (the rhynchocoel)
ROTIFERA (wheel bearer): refers to the ciliated corona for locomotion and food-gathering currents; pharynx highly muscular
and containing jaws (trophi) for grasping, crushing or grinding prey or attaching to a host; toes with adhesive glands
ACANTHOCEPHALA (spine or thorn-head): 1-2 large, acellular collagenous sacs (ligament sacs) in the pseudocoel,
supporting the gonads; adults with proboscis containing intracellular hooks; probably derived from rotifers; modify behaviour of
intermediate host (crustaceans/arthropods) so that it is more likely to be consumed by final host (human/birds) (i.e. photophobic
organisms begin to travel towards light where they are more likely to be consumed)
MOLLUSCA (soft): dorsal epithelium forming a mantle, which secretes shell and calcareous band of teeth (radula) in the
esophagus, used for feeding (not present/lost in bivalves); ventral body wall muscles develop into locomotory or clinging foot
-Gastropoda (stomach foot) — snails, slugs: visceral mass and NS become twisted 90-180º (exhibiting torsion) during
embryonic development; proteinaceous shield on the foot (operculum) to which columellar muscle attaches and serves as a
barrier; advantages of torsion (less sediment on gills, sense organs on gills at front, retract mantle and head first for
protection from predators); mantle cavity houses the gills; shell coiling to accommodate animal
Prosobranchia (anterior gill) — sea snails: mantle cavity generally anterior due to torsion
Opisthobranchia (posterior gill) — sea slugs: mantle cavity lateral or posterior due to detorsion or lost; often feed on
jellyfish — able to retain stinging cells, surpassing them and taking them into the gut where they migrate to the gills or
extensions of the body providing protection
Pulmonata (lung) — terrestrial slugs: mantle cavity highly vascularized and modified to form a lung; may have a
snorkel-like structure when under water — secondarily evolved gills; not homologous or related embryonically or
developmentally
-Bivalvia (two valved/hatchet foot) — clams, mussels, scallops, oysters: two valved shell; body flattened laterally; bissell
threads hold the animal on rocks (water soluble, organic adhesive); anterior and posterior adductor muscles close bivalve;
scallops and mussels have a single large muscle; gill is primary method of filter feeding
Protobranchia (first gill): small gills, function primary as gas exchange surfaces; food collected by long thing, muscular
extensions of tissue surrounding the mouth (palp proboscides)
Lamellibranchia (plate gill): gill modified to collect suspended food particles, in addition to serving as gas exchange
surfaces; secretions of proteinaceous attachment material (in the form of threads) by a specialized gland (byssus
gland) in the foot
-Cephalopoda (head foot) — squids, octopods and nautiloids: shell divided by septa, with chambers connected by the
siphuncle: a vascularized strand of tissue contained within a tube of calcium carbonate (shell reduced or lost in many
species); closed circulatory system; foot modified to form flexible arms and siphon; ganglia fused to form a large brain
encased in a cartilaginous cranium; high speed swimmers; most body functions dominated by cilia; systemic heart with 2
additional hearts at the base of each gill — high rate of metabolic output; internalized shell except for nautiloids (continuously
Developmental Characteristic
Protostomes (first mouth)
Deuterostomes (outpocketings of gut)
Mouth origin
From blastopore
Never from blastopore
Coelom formation
Schizocoely
Enterocoely
Mesoderm origin
4d cell
Other
Cleavage pattern
Spiral, determinate
Radial, indeterminate
You're Reading a Preview

Unlock to view full version

Only pages 1-2 are available for preview. Some parts have been intentionally blurred.

growing and adding shell chambers— buoyancy control); cuttlefish use chromatophores to blend in — high processing
power
ANNELIDA (ring) — segmented worms: one or more pairs of chitinous setae; adults possess at least 1 pair of setae or
chetae and all are vermiform (worm-shaped); soft bodied, circular and longer than they are wide; bodies consist of repeating
segments; serial repetition of organ systems — metamerism or metameric segmentation
-Polychaeta (many setae): paired lateral outfoldings of the body wall — parapodia (used as paddles); secretes mucous bag
for feeding; live in sand tube that it constructs
-Clitellata (pack saddle): pronounced cylindrical glandular region of the body (clitellum) that plays important roles in
reproduction; permanent gonads
Oligochaeta (few setae) — earthworms: lack parapodia; anteriormost region of the body (prostomium) lacks
conspicuous sensory structures, such as eyes and tentacles; oligochaete body plan is relatively invariant among
species; there are usually no specialized respiratory organs; gas exchange is accomplished by diffusion across a moist
body wall
Hirudinea — leeches: posterior sucker; tubificid worms present in toxic environments
-Pogonophora (beard bearer) — vent worms (Riftia): gut tissue (endoderm) forms an organ (trophosome) that become filled
with chemosynthetic bacteria (converting H2S); segmentation confined to small rear portion of animal (opisthosoma); live in
extreme environments (high temperature, high pressure)
ARTHROPODA (jointed foot): epidermis produces a segmented, jointed and hardened (sclerotized) chitinous exoskeleton,
with intrinsic musculature between individual joints of appendage; complete loss of motile cilia in adult and larval stages
Trilobitomorpha (three-lobed form): 2 anterior-posterior furrows divide the body into 3 regions (2 lateral, 1 central)
-Trilobites (all extinct): medial lobe and two lateral lobes
Chelicerata (claw): absence of antennae; body divided into 2 distinct portions (prosoma and opisthosoma) with no distinct
head; first pair of appendages (the chelicerae) on the prosoma are adapted for feeding
-Merostomata (horseshoe crabs i.e. Limulus): appendages on the opisthosoma are flattened and modified for gas exchange
as “book gills”; simple eye
-Arachnida (spider): anterior pair of appendages borne by the prosoma are chelicerae which tear apart food prior to ingestion;
next pair of appendages are the pedipalps, which are various modified for grabbing, killing, or reproducing and in some
species may have a sensory function as well
Mandibulata (jaw): appendages on the third head segment are modified as mandibles for chewing or grinding food; retinula
(compound eyes) contain 8 cells
-Myriapoda (many feet): Chilopoda and Diplopoda contain the centipedes and millipedes (bulldozers)
-Insecta/Hexapoda (six-footed): fusion of 1 pair of head appendages (the second maxillae) to form a lower lip (labium); loss of
all abdominal appendages
-Crustacea: head bears 5 pairs of appendages, including 2 pair of antennae; development includes a common, distinct
triangular larval form, the nauplius bearing 3 pairs of appendages and a single medial eye
Malacostraca (soft shell)shrimps, crabs, lobsters, isopods: thorax with 8 segments, abdomen with 6-7 plus telson;
appendages on the 6th abdominal segment are flattened to form uropods
Branchiopoda (gill foot) brine shrimp, fairy shrimp: on each thoracic appendage the coxa (basal segment) is
modified to form a large flattened paddle (functions in gas exchange and locomotion); brine shrimp use salt
transporting cells to excrete excess salt — capable of anhydrobiosis to survive extreme conditions; can dry up and
come back to life when water appears again
Ostracoda (a shell): head and body are enclosed in a bivalved carapace, which lacks concentric growth rings; trunk of
body posses no more than 2 pairs of limbs
Copepoda (oar foot): thorax with 6 segments, abdomen with 5; first segment of thorax fused to head; loss of all
abdominal appendages; single “naupliar” eye; swim with second antennae; create vortices with first antennae
Cirripedia (hairy foot) — barnacles: all barnacles are highly modified for attachment to hard substrates, including the
outer surfaces of other animals or for parasitism; thoracic limbs modified as filtering cirri; no abdomen; swimming larval
stage and sessile adult stage — stands on its head for metamorphosis; filter feeder; shell provides protection
TARDIGRADA (slow walker) — “water bears”: mouthparts include protrusible, oral stylets for piercing plants and, to lesser
extent, animal tissues
▪︎ Stage 1: active, hydrated
▪︎ Stage 2: dehydrating, actively rearranging and altering tissues and tucks in
▪︎ Stage 3: tun stage (resistant to anything); membranes are stabilized by water; when water is taken away, lipids look for more
favourable ways to interact; membranes form micelles, tearing them apart. When water is added, membranes are no longer in
proper form — anhydrobiosis, trahalose (disaccharide) is required in high concentrations- replaces the capacity for hydrogen
bonding that water has and so maintains structural integrity of cell membrane when water is absent —rehydrates
You're Reading a Preview

Unlock to view full version