Biology 5 ( NOT QUIZZED ON) AND Biology 6 (QUIZ 5)

1-52 not quizzed on

Animalia

synapomorphy:

• special types of junction between cells — cell adhesion proteins

• extracellular membrane with collagen and proteoglycans

Traits

• multicellular

• heterotrophic by ingestion instead of absorption

• carbohydrate reserves/food stored as glycogen

• no cell walls

• special tissue: muscle and nervous tissue (only in Eumetazoa)

• diploid life cycle

  • only gametes are haploid

What are the types of animal symmetry?

asymmetrical - no planes of symmetry

radial - many planes of symmetry

bilateral - one plane of symmetry (mirror images)

Bilateral sides are

dorsal - top side

ventral - bottom side

anterior - head on

posterior - back side

early embryological plan

1. Cleavage: zygote divides by mitosis and becomes blastula

2. Blastula = hollow ball of one layer of cells

• has a blastocoel (cavity) = hollow area

3. gastrulation occurs, where cells of blastula will start to move into the interior and form a gastrula

4. Gastrula structure:

   1. Blastopore = the opening

   2. Blastocoel = gap/cavity between two cell layers

   3. Archenteron = future digestive system located in the center

   4. Endoderm = inner cell layer

   5. Ectoderm = outer cell layer

Primary Germ layers

Ectoderm

Endoderm

Mesoderm

Ectoderm

outer layer that develops into nervous system and outer covering of the body

Endoderm

surrounding the archenteron, and becomes the digestive system

Mesoderm

In some animals, mesoderm forms between ectoderm and endoderm

Develops into muscle and other internal organs

What is diploblastic?

Two layers of cells in the gastrula: ectoderm and endoderm

What is triploblastic?

Three layers of cells in the gastrula: ectoderm, mesoderm, and endoderm

Body Cavity

fluid filled space other than the digestive cavity

only in bilateral, triploblastic animals

Significance:

• cushion organs

• allows internal organs to grow and operate independently of the body wall

• hydrostatic skeleton in soft bodied animals (provides support for their muscle movement)

Acoelmate

no body cavity, solid & filled with cells

ectoderm —> mesoderm —> endoderm —> gut

Coelomate

body cavity present

completely surrounded/lined with tissue derived from mesoderm = coelom

ectoderm —> mesoderm —> coelom—> mesoderm —> endoderm —> gut

Pseudocoelomate

cavity present, but not completely lined by tissue of mesodermal origin = false coelom

ectoderm —> mesoderm —> coelom —> endoderm —> gut

What is the basal group for Animalia?

Porifera

Porifera

Sponges

no tissues or organs — cells are independent of e/o and therefore not considered tissue/organs

asymmetrical

Jelly like extracellular matrix between epidermis and gastrodermis is called mesohyl

• contains spicules — skeletal material for support

Filter feeders - food particles digested intracellularly by choanocytes

Synapomorphies:

• internal auriferous system - intracellular digestion

  • Has internal spongocoel lined with choanocytes (collar cells) that digest food

  • body wall perforated by pores

• Spicules provide support - can be chalk, silica or organic material

How Porifera feed

water enters spongecoel through pores (Ostium)

choanocytes lining body wall trap food particles

water leaves through Osculum

Eumetazoa (synapomorphies and groups)

true tissue and organs

synapomorphy:

• true body symmetry: radial or bilateral

• true endoderm and ectoderm

• epithelial tissue

• nervous tissue

• extracellular digestion by ingestion

Groups:

1. Radiata

2. Bilateria

What are the two basal groups that are diploblastic and radial?

Cnidaria

Ctenophora

Ctenophora

comb jellies

some believe to be basal

Cnidaria

hydras, jellyfish, sea anemones, corals

radial symmetry

diploblastic: only have endoderm and ectoderm

between endoderm and ectoderm is the extracellular matrix mesoglea

organs: gonads (everything else is tissue)

digestive system = gastrovascular cavity

simple nerve net (no brains)

two body forms:

1. polyp - sessile (non moving), mouth up, thin mesoglea (ex. hydra)

2. medusa - free swimming, mouth down, thick mesoglea (ex jellyfish)

synapomorphy: special type of cells called cnidocytes with nematocyst organelle

• nematocyst contains toxins to protect themselves

Three clades of cnidaria

hydrozoa - alternating polyp/medusa

scyphozoa - medusa dominant

anthozoa - polyp only

Bilateria

synapomorphies:

• bilateral symmetry

• has mesoderm (that makes them triploblastic)

  • mesoderm = from which muscle develops from

Some degree of cephalization, or clear head part

• extensive cephalization in some groups

most have body cavity

• coelomates, pseudocoelomates

• few are acoelomates due to LOSS of coelom

What are the two major phylogenetic branches of Bilateria?

Protostomia

Deuterostomia

Protostomia

• early cell fate: determinate (at 8 cell stage)

  • cells assigned to become specific parts of the body

Synapomorphies

• spiral cleavage (zygote —> blastula)

• blastopore (opening to archenteron) becomes mouth

  • proto = first

  • stomas = mouth

• Schizocoelom coelom formation

  • split

Deuterostomes

• radial cleavage

Synapomorphies

• early cell fate: indeterminate (at 8 cell stage)

  • no determination made and cells develop into identical individuals “twins”

• blastopore (opening to archenteron) becomes anus

  • deutero = second

  • stomas = mouth

• Enterocoelom coelom formation

  • looks like a cat

Branches in Protostomia

Lophotrochozoa

Ecdysozoa

Lophotrochozoans (synapomorphy & groups)

monophyly supported by DNA! (so no synapomorphies :D)

Groups:

Platyhelminthes, Mollusca, Annelida

Platyhelminthes

flatworms (“platy” = flat)

gastrovascular cavity — one opening, but is highly branched inside (not sac like) so it has high surface area

simple nerve net — ventral nerve cords

some degree of cephalization

• can tell where head is

• photoreceptive organs (eyes) that detect light intensity but no images formed

monoecious - have male and female organs in one individual

Synapomorphy:

• Acoelomate (secondary loss of coelom)

• Dorsoventrally flat (ribbon like)

  • allows their dorsal/ventral side to be of diffusion distance (no circulatory system or respiratory system so they rely on simple diffusion)

  • too many cell layers make surviving off diffusion impossible

Groups in Platyhelminthes

Turbellaria - free living planaria

Trematoda - flukes; ALL parasitic

Cestoda - tapeworms; parasitic

Trematoda Life Cycle (Fluke: Schistosoma Mansoni)

• adults found in blood vessels in intestine

• diecious: male and female mate (permanently hooked together)

• produce thousands of eggs with embryos released into intestine

• Leaves bodies through feces and once in water they hatch —> ciliated larvae

• Larvae will live in an intermediate host (ex. snail) and feed on tissues of snail

• It leaves the snail as a tailed larva, with sharp anterior part that can attach to a human leg (in water)

• Get into blood system and veins/arteries in digestive system where they mature into adults

Cestoda

• Scolex attaches to wall of intestine

• Proglottids repeating units of ovaries and testes

Synapomorphy: no gastrovascular cavity/digestive structure

• relies on human digestive system to digest for them

• secretes SOME slight degree of extracellular enzymes

How humans catch tapeworms (Cestoda)

• Self fertilizing —> embryos in intestine

• When feces is exposed to pasture/land, it contaminates food for secondary host (ex. cow)

• cows act as secondary host and they bore into intestine wall to form encysted larva

• Humans pick it up when eating undercooked meat that is exposed to tapeworms

Mollusca

coelomates

complete digestive system

most internal organs inside a visceral mass surrounded by a mantle

• visceral mass and mantle both derived from ectoderm (but they’re still different layers)

sexually dioecious

Respiratory system— by gills

Open circulatory system— blood and interstitial fluid are not separate (called hemolymph)

Synapomorphies

• Muscular foot

  • muscular organ for locomotion

• Mantle

  • secretes mantle shell

  • mantle cavity between mantle and visceral mass that is NOT considered a coelom

• Radula

  • mouth has a rasping organ made out of chitin (teeth)

Groups in Mollusca

Polyplacophora, Gastropoda, Bivalvia, Cephalopoda

Polyplacophora

chitons

synapomorphy: 8 dorsal plate mantle shell

Gastropoda

snails and slugs

many are terrestrial but they are still required to stay in moist environments

synapomorphy: internal torsion

• inner organs twist 180 degrees

Bivalvia

orientation: opening is downward

• hinge = dorsal (top side)

• foot = ventral (bottom side)

anterior and posterior adductor muscles open and close the shell— relaxing muscle opens valves

foot digs into soil

filter feeders = requires closure of the mantle

• in current siphon pulls in water, excurrent siphon releases water

• food caught in Ctenidia covered in cilia and mucus

Ctenidium (gills) - respiratory organs also for filter feeding called

synapomorphy: mantle shells in two halves called valves

Cephalopoda

squid, octopus, nautilus

well-developed marine animals

all predators —> well developed nervous system

• intelligent

eyes converged with our eyes in terms of design - good vision

synapomorphies:

• head and foot fused together

  • “cephalous” = head

  • “poda” = feet

• reduction or loss of mantle shell (still have mantle cavity)

Annelida

segmented worm

closed circulatory system

• red blood (has hemoglobin)

excretory system— pair of metanephridia in each segments (tubes where nitrogenous waste/urine and salt balance is controlled in coelom)

monoecious

synapomorphies:

• segmented coelom portioned by septa

• four bundles of chaetae (tiny hairs) per segment

What are the groups in Annelida?

Polychaeta

Clitellata

Polychaeta

feather worms

synapomorphy: each segment have parapodia

• flaps function for locomotion, anchoring them on ocean floors, and as gills

Clitellata (Synapomorphy and clades)

synapomorphy: Clitellum

• wider segment used for laying eggs (reproduction)

Groups:

1. Oligochaeta

2. Hirudinea

Oligochaeta

earthworms

Hirudinea

leeches

has suckers

facultatively ectoparasites (latches onto animal, drills hole to suck blood, then gets off)

Sucking blood = problems with coagulation

• hirudin produced in saliva (anticoagulant that prevents blood clotting)

Ecdysozoa

synapomorphies:

• cuticle outside epidermis

  • armor kinda (outer skeleton)

• growth by molting/ecdysis

  • secretes enzyme to digest part of cuticle

  • thin regions of cuticle are broken by taking in air and water where they pull themselves out

  • old cuticle is left behind and new cuticle is secreted

    • they take in air and water to puff themselves up until new cuticle fully forms

Groups in Ecdysozoa

Nematoda

Anthropoda

Nematoda

roundworms

pseudocoelomate

complete digestive track

longitudinal muscle - not circular muscles

some degree of cephalization

dioecious - internal fertilization

• some females can lay 200,000 eggs a day

nervous system: four longitudinal chords, anterior neural ring (brain)

Decomposers or parasites

synapomorphy:

• Amphids - chemosensory organs on head that pick up chemicals from liquid to identify them

Trichinella Spiralis

Nematoda parasite

Life Cycle:

1. worm infects pigs — inside digestive tract

2. male and females mate, producing eggs that form larvae

3. larvae circulate into muscles of pig

4. when pig dies, other pigs or rats or humans eat it

5. In humans, when they eat undercooked pork, the worm will end up in the digestive system

6. They reproduce and larvae end up in muscles — cannot be removed

7. however, assuming no animals/humans eat infected humans, the cycle ends there once the human dies

Hook worms

Grab onto foot, drill into body

Filarial worms

microscopic

causes Elephantiasis —swollen leg

• vectors: mosquitoes

• female mosquito drills hole, where worms drop off mosquito head and crawl into hole

• plugs up lymphatic system

Pin worms

almost all little kid has these

lays eggs on anus where toddlers scratches and spreads with hands

Arthropoda

spiders, ticks, mites, scorpions, lobsters, crayfish, centipedes, insects, etc.

most species rich clade

• largest phylum

high degree of cephalization

open circulation — dorsal heart

dioecious

gas exchange through…

• gills if aquatic (evagination)

• book lungs if terrestrial (invagination)

• trachea if insects

Synapomorphies:

• segmented (surface)

• articulated exoskeleton of chitin

  • secretes collagen and chitin

  • articulated = flexibility within segments (think joints)

  • provide attachments for muscle

  • protection

  • prevents water loss

    • adapted to terrestrial conditions

  • molt to grow

• jointed appendages

  • legs with joints and muscles to bend

  • mouthparts have joints

Trachea in Insects

• piping system

• two opening spiracles (one on prothorax and one on metathorax)

• each abdominal segment has a pair of spiracles

• trachea branches into tracheoles that deliver O2 to cells

• respiration and gas exchange is INDEPENDENT to circulatory system

  • unlike us for example: blood provides O2

What are the groups in arthropoda?

Trilobitomorpha*

Chelicerata

Mandibulata

Trilobitomorpha*

EXTINCT at end of Paleozoic (Permian-Triassic)

synapomorphy: body divided into three longitudinal sections

Chelicerata

spiders, ticks, mites, scorpions (NOT INSECTS)

no antennae — instead have the chelicerae

Synapomorphies:

• chelicerae and pedipalp mouthparts

  • has jointed appendages

  • first post-oral segment = chelicerae (has toxin glands)

  • second post-oral segment = pedipalps (paired)

Groups of Chelicerata

Xiphosura (horseshoe crabs)

Arachnida

Arachnida

Chelicera = fangs

Pedipalp = legs

Tagma = collection of segments bound together to form a body region

Two body regions:

• cephalothorax - brain, (usually 8) eyes, 8 legs attached

• abdomen - digestive, circulatory, respiratory system

Respiratory system = book lungs

Eyes - two front eyes larger and see better

• simple eyes can see motion and intensity of light

Weaver spiders - have 7 types of glands to produce 7 types of silk (protein)

Synapomorphy:

• Four pairs of walking legs (8 legs)

Mandibulata

centipedes, millipedes, crustaceans, insects

Synapomorphy:

• mandible mouthpart

• antennae

  • homologous to chelicerates in spiders

  • for smell

What are the groups in Mandibulata?

Myriapoda

Pancrustacea

Myriapoda

centipedes and millipedes

Mouthparts layered top to back/bottom:

• Mandibles —> Maxillae —> Labium

Synapomorphy:

• unique internal head structure

  • swinging tentorium acts as a brace to prevent collapsing of head from chewing

• strong antisense expression of Ultrabithorax gene

  • developmental gene on embryo

Groups in Myriapoda

Diplopoda

Chilopoda

Diplopoda

millipedes

body consists of head and trunk

herbivorous

Synapomorphy:

• 2 pairs of legs per segment

  • segments are fused and appear to be one segment so it’s really 1 pair per segment but looks like 2

Chilopoda

centipedes

body consists of head and trunk

one pair of legs per segment

predatory (venemous)

Synapomorphy:

• 1 pair of legs are as poison fangs

Pancrustacea

monophyly strongly supported by neuroanatomical features (brain structure) and molecular data

Synapomorphy:

• 4 crystalline cone cells in ommatidia (units with their own lens) of compound eye

  • lens cannot be focused

  • pixel images formed

Groups in Pancrustacea

Crustacea

Insecta or Hexapoda

Crustacea

Paraphyletic!

lobsters, crayfish, crab, krill, shrimp, isopods, barnacles

2 pair of antennae

variable number of legs

compound eyes (synapomorphy for arthropods?? idk)

aquatic species have gills

terrestrial versions: ex. roly-poly

• book lungs

calcium carbonate deposition in exoskeleton

Insecta (Hexapoda)

Synapomorphy

• 3 tagma/body regions

  • head, thorax, abdomen

• 3 pairs of legs

• mostly with wings (Pterygota)

  • ancestrally without wings: silverfish and kin

  • LOST wings: ants, fleas, lice

How to tell if an insect lost wings or never evolved to have wings?

dorsal plate = tergum

ventral plate = sternum

in between is an intermembrane that is flexible

legs in intermembrane space reinforced at the base by sclerites

in winged flight, legs have to be reinforced even more because flight muscles contracting cause wings to go up and down may cause legs to collapse

Presence of reinforced sclerites = winged ancestors (LOST WINGS)

Postembryonic Development in Insects

Development AFTER hatching from egg

3 Types:

1. Ametabolous (silverfish)

• young look like adult except in proportion

• sexually immature and continue to molt after maturity

2. Hemimetabolous (grasshoppers, cockroach, aphid)

• young (nymphs) resemble adult except in proportion

• young (nymphs) lack wings but have external wing pads

• continue to molt until maturity —> then NEVER molt again

• after last molt, they develop wings

3. Holometabolous (mosquitoes, beetles, moths, bees, butterflies)

• young are quite different from adults

• internal wing pads

• egg —> larva —> pupa —> adult

  • pupa only found here

  • immatures are called larvae

Impact of Insects on Humans

Act as disease vectors

• malaria (anopheles mosquitoes)

• sleeping sickness (tsetse flies)

• bubonic plague (caused by yersinia pestis but spread by fleas)

• filarial diseases (nematodes)

• yellow fever

Pests of crops, stored products, wood (termites)

Predators - eat other insects, including pests

• Biological Control

  • ex. Cottony cushion scale on citrus

    • vedalia beetle feeds exclusively on cottony cushion scale

    • controlled issue of cottony cushion scale and now are kept in low populations

  • Parasitoid wasps - land on victim and lay eggs on/in it. Ovipositor will inject eggs into caterpillar. After they hatch, they’ll eat just enough to keep the caterpillar alive until it pupates. Then it eats the whole thing

Contributions: honey, silk, food, pollination

What are the groups in Deuterostomia

Echinodermata

Chordata

Echinodermata

starfish, sea dollars, sea urchins (spiny skinned animals)

diecious — external fertilization

Synapomorphy:

• Pentaradial symmetry in adult

  • five planes of radial symmetry (despite being bilateral, they regained the radial trait)

• Water vascular system—tubed feet— for feeding movement and gas exchange

  • madreporite — porous, sieve-like plate where water enters or exits the system

  • stone canal — A rigid tube that channels water downward from madreporite

  • ring canal — encircles central mouth

  • radial canal — five canals that branch from ring canal into each arm

  • tubed feet in ambulacral grooves (oral side, underside)

Chordata

Pharyngeal slits (at some stage of life)

• Pharynx have slits that contain mucus to catch food

• Pharynx are immediately posterior to mouth

• Also used as gills for respiration and filter feeding

Synapomorphy:

• notochord

  • flexible rod between gut (digestive system) and dorsal nerve cord

• dorsal, hollow nerve cords —Write the whole thing!

• muscular postanal tail

• endostyle or thyroid

  • cluster of cells involved in iodine and thyroid hormone production

• dorsoventral inversion - bone morphogenic protein, chordin gradients reversed

  • HOX genes: instructions that lays out want is the anterior/posterior part of the body

  • 2 HOX genes that set gradients for gene expression of bone morphogenic protein and chordin

  • In CHORDATES: dorsal cells code for chordin while ventral cells code for bone morphogenic protein

    • In Hemichordate (ancestral group), it’s the opposite —> synapomorphy is reversed gradients

What are the groups in Chordata?

Cephalochordata

Urochordata

Craniata

Cephalochordata

lancelets

segmental muscles

filter feeders

Urochordata

tunicates; sea squirts

chordate features found in larvae only

Filter Feeders:

• contain incurrent siphon to take in food in basket-like pharynx and into the tunic then out the excurrent siphon

• food caught goes into stomach and intestines…

• anus opens into tunic close to the excurrent siphon

Synapomorphy:

• tunic composed of collagen

Craniata

Synapomorphy:

• brain in cranium (NOT SKULL)

  • cranium = cartilage that encases brain

What are the branches in Craniata?

Myxini

Vertebrata

Mixini

hagfish

not vertebrates = no spine

open circulatory system

Vertebrata

High degree of cephalization: easy to tell where head is

Synapomorphy:

• vertebral column

  • vertebrae protects the spinal cord

What are the groups in Vertebrata?

Lampreys

Gnathostomata

Lampreys

look like hag fish but are jawless

dorsal fins

cartilaginous endoskeleton (inside epidermis)

2 chambered heart (atria and ventricles)

Synapomorphy:

• Rasping, blood-sucking mouthparts

What are early jawless vertebrates ancestors?

Ostracoderms

Gnathostomata

jawed vertebrates

have teeth to hold onto prey not to chew

Synapomorphy:

• jaws

  • derived from pharyngeal slits

• 2 sets of paired appendages

  • pelvic and pectoral appendages or fins

• mineralized axial skeleton (bone!)

What are early jawed vertebrate ancestors?

Placoderms

What are dermal bone?

Bone that forms some of the plates that surround skull

Bone derived from ectoderm

• usually bones derived from mesoderm

What are the groups in Gnathostomata?

Chondrichthyes

Osteichthyes

Chondrichthyes

sharks, rays

lateral line system: sensitive to changes in water pressure

• how they “see” because they have bad vision

2 chambered heart

Some are suspension (filter) feeders, some are carnivores

Synapomorphy:

• Skin covered by denticles of enameloid

  • skin of sandpaper like texture

• pelvic claspers in males

  • for holding onto females during mating

• loss of mineralization (bone): cartilaginous endoskeleton

Osteichthyes

Rest of vertebrata!

bony endoskeleton

Synapomorphy:

• lungs (or derivatives of lungs, like swim bladders)

  • ventral offshoots of pharynx

• operculum

  • flap that protect gills and pushes water through (for respiration)

What are the groups in Osteichthyes?

Actinopterygii

Sarcopterygii

Actinopterygii

ray finned fish

MOST have swim bladders for buoyancy

Synapomorphy:

• lepidotrichia

  • cartilaginous rods that keeps fin open and flat

Sarcopterygii

lobe finned fish

Synapomorphy:

• base of pelvic pectoral fins with articulate bone

  • ex. jointed fins, digits, wrists

Left is Lobed Finned Fish

Right is Ray Finned Fish

What are the groups in Sarcopterygii?

Dipnoi

Actinistia

Tetrapoda

Dipnoi

lung fish

have lungs that switch between breathing with gills/lungs

can walk on land with fins

not many around today

Actinista

Coelacanths

Eusthenopteron

Devonian Lobe Finned Fish that resemble dipnoi lung fish

have homologous structures in fins similar to tetrapod forelimb

Tetrapoda

Breath by means of lungs, solely or more efficiently than fish

Synapomorphy:

• 2 pairs of legs

  • derived from bony structure in fins

• pelvic fused to backbone

• neck

  • allows head to be moved up, down, side to side