BIO  12  LAB  EXAM  -­‐  Ex  1,  2,  3

GAMETOGENESIS

OVARY

• Theca  externa  (visceral  peritoneum)  –  outer  connec6ve  6ssue  covering  (2N)

• Sacs  –  house  of  developing  egg  cells  suspended  within  t.  externa  (2N)

• Oogonia  –  smaller;  arise  from  successive  mitosis  of  embryonic  PGCs,  not  yet  accumulated  yolk  (2N)

• Oocyte  –  larger;  dark;  undergo  growth  and  meito6c  prophase;  yolk,  glycogen,  pigments  (1°  (2N)  2°  (N))

• Theca  interna  –  inner  membrane  covering  each  sac;  smooth  muscle  fibers  (2N)

OVARY

• OOCYTE– Nucleus/germinal  vesicle  –  stain  lighter;  with  prominent  nuclei

– Nuclei/gemimal  spots

– Follicle  cells  w/  darkly  stained  oval  nuclei  -­‐>  secretes  estrogen

OVARY

• Mature  ova  not  found  in  ovary  –  oocytes  leave  by  hormonal  sSmulaSon  prior  to  compleSon  of  maturaSon  /  reducSon  division

• First  arrest:  first  maturaSon  division– Second  maturaSon  division  begins  upon  entering  of  eggs  to  oviduct

• Second  arrest:  at  Metaphase  II– Oogenesis  resumes  aVer  ferSlizaSon  

TESTIS

• Visceral  peritoneum

• Numerous  seminiferous  tubules  –  within  tesSs

• Spermatocysts  –  compartments  with  various  stages  of  spermatogenesis– Spermatogonia  (2N)• Tightly  packed  cells  with  lightly  stained  nuclei  showing  threads

• Near  periphery  of  s.  tubules• Increase  by  ordinary  mitosis;  with  normal  diploid

TESTIS

– SpermatocytesPrimary  –  largest  s-­‐geneSc  cells  (2N)• Early  growth:  w/  vesicular,  lightly  stained  nuclei• Shows  meioSc  chromosomes:

– Pairing  of  homologous  chromosomes– Crossing-­‐over– Progressive  chromosomal  contracSon

Secondary  s-­‐cytes  –  slightly  smaller  cells  (N)• With  darkly  stained  nuclei• Some  with  highly  contracted  chromosomes• Haploid  no.  of  dyads  

TESTIS

– SpermaSds  –  produced  by  2nd  meioSc  division  by  2ndary  S-­‐cytes  (N)• w/  haploid  no.  of  monad• Very  small;  w/  slightly  stained  nuclei

– Spermatozoa  –  haploid  (N)• Masses  of  hair-­‐like  structures• A^ached  to  sertoli  cells

– All  spermatogenic  cells  are  found  within  spermatocysts  except  spermatozoa

– Cells  in  spermatocyst  are  in  the  same  stage

TESTIS

• Leydig  cells  –  between  seminiferous  tubules;  secrete  androgens

• Sertoli  cells  –  elongated  triangular  cells,  supply  nutrients

• Bases  a^ached  to  basement  membrane  of  seminiferous  tubules

• Provide  mechanical  support  &  nourishment  to  spermatozoa

PROPHASE  I  of  MEIOSIS  I

1. Leptotene  –  similar  in  appearance  to  spermatogonia  but  boundaries  more  disSnct– Found  within  porSons  of  dark  row  of  early  

spermatocytes

– w/  finely  granular  nuclei

– w/  masses  of  lightly  stained  beaded  threads

– Display  graduaSons  from  irregular  to  more  circular  appearance

– Chromosomes  condense

2.  Zygotene  –  homologous  chromosomes  side  by  side  &  gene  by  gene  with  each  other– w/  convergence  towards  one  side  of  nucleus  (bouquet  configura6on)

– Pairing  without  crossing  over3.  Pachytene  –  with  thicker  chromosomes– Chromosomes  resemble  minute  railroad  tracks  winding  about  within  the  nuclear  membrane  w/  gently  spiraled  twists

– Crossing-­‐over  or  exchange  of  gene6c  materials  between  homologous  chromosomes  takes  place  

PROPHASE  I  of  MEIOSIS  I

4.  Diplotene  –  chromosomes  condense  more– Becomes  slightly  separated    while  sister  chroma6ds  s6ll  remain  aTached  at  the  centrometric  region

– Separa6on  is  complete  except  at  points  where  crossing-­‐over  has  occurred

– Chismata  –  points  of  interchange5.  Diakinesis  –  shortening  of  chromosomes;  relaxa6on  of  pairing– Points  of  contact  between  homologues  diminish– Presence  of  tetrads  appearing  like  fuzzy  loose  loops– Chromosomes  prepare  for  alignment

PROPHASE  I  of  MEIOSIS  I

OTHER  SHIZZLE

• Increase  of  nucleoli  in  nucleus  –  producSon  of  ribosomes  w/c  synthesizes  proteins  needed  for  yolk  producSon

• Melanin  of  oocytes  –  near  the  periphery• Where  sperm  arise  from:– Acrosome  cap:  golgi  apparatus– Head:  nucleus– Neck/midpiece:  mitochondria– Tail:  centrioles

Early  Development  of  the  Frog

LIFE  STAGES1. Gametogenesis  –  produce  haploid  cells,  

gametes  (N)2. FerSlizaSon  –  return  back  to  2N,  zygote  (2N)3. Cleavage  –  blastula4. GastrulaSon  –  morphogeneSc  movements  

and  cells  migraSng,  gastrula• Ectoderm  -­‐>  CNS,  skin• Mesoderm  -­‐>  Circulatory,    Excretory• Endoderm  -­‐>  S  (WHAT),  gonads• Epiboly,  invaginaSon,  involuSon

LIFE  STAGES

5. Organogenesis  –  organ  systems

6. Growth

7. Senescence

8. Death

DEFINITION  OF  TERMS

• FerSlizaSon  –  union  of  sperm  and  eggs

• Cleavage  –  rapid  division  of  the  ferSlized  egg  to  produce  more  embryonic  cells

• GastrulaSon  –  morphogenic  cellular  movements

• Organogenesis  –  differenSaSon  of  organs

• NeurulaSon  –  development  of  the  neural  tube

BLASTULATION

• BLASTULA  –  embryo  found  at  end  of  cleavage

BLASTULA

• Animal  hemisphere  –  comprised  of  smaller  cells  known  as  the  MICROMERES

BLASTULA

Vegetal  Hemisphere  –  comprised  of  cells  known  as  MACROMERES

BLASTULA

• Blastocoel  –  cavity  found  during  blastula  stage;  disappears

• Blastoderm  –  cells  surrounds  blastocoel

GASTRULATION• InvaginaSon  –  sinking  in  of  cells

• Epiboly  –  gradual  spreading  and  enveloping

• InvoluSon  –  roll  inward

• First  indicaSon  –  blastopore  and  dorsal  lip

GASTRULA

• Blastopore  –  crescenic  groove  bordered  by  thickening  of  cells

• Dorsal  lip  –  formed  by  invaginaSon  of  cells  in  the  region  of  gray  crescent;  borders  yolk  plug;  cells  above  make  involuSon

GASTRULA

GASTRULA

• Archenteron  –  formed  between  gray  crescent  cells  (chordamesoderm)  and  yolk-­‐laden  cells  (presumpSve  endoderm);  becomes  oral/digesSve  cavity

• Chordamesoderm  –  dorsal  roof  of  archenteron  (becomes  notochord)

GASTRULATION

• Complete  gastrula:  with  plug  finally  withdrawn  into  archenteron

• Whole  embryo:  anteriorly  broad  &  posteriorly  narrow

NEURULATION

• Neural  tube  –  primordium  of  the  central  nervous  system

• Neural  plate  –  with  thickened  &  fla^ened  ectoderm

• Neural  groove  –  sinking  of  neural  plate

• Neural  folds/ridges  –  paired  elevaSons  alongside  the  groove

• PresumpSve  epidermis  –  remaining  ectoderm

NEURAL  PLATE  STAGE

• Neural  plate  –  flat,  thickened  dorsal  layer  of  ectodermal  cells

• Chordamesoderm  cells  –  separate  into–Median  axial  rod– Notochord–Mesoderm– Extend  laterally  between  presumpSve  epidermis  and  the  yolk  laden  endoderm  lining  the  lumen  of  the  archenteron

NEURAL  GROOVE  STAGE

• Notochord  –  well-­‐defined  tube  below  neural  fold

• Mesoderm  –  thickens  &  penetrates  farther  ventrally

• Endodermal  layer  –  more  disSnct

NEURAL  TUBE  STAGE

• Mesodermal  somite  or  epimere

• Neurocoel  –  cavity  enclosed  by  the  neural  tube

• Intermediate  mesoderm  or  mesomere  –  lateral  to  mesodermal  somite

• Lateral  plate  mesoderm  or  hypomere– Soma6c  Mesoderm  –  outer  layer

– Splanchnic  mesoderm  –  inner  layer

– Coelom  –  space  produced

TADPOOOOOLE

ECTODERMAL  DERIVATIVES

Ectoder

Epiderm

Epiderm Epithelial  lining    mouth

Cornea  

Neural  

Neural  

Nervous  

Neural  

Melanoc Splanch Denture   Cranial   Mening Branchi

• EPIDERMIS– O:  epidermal  ectoderm

– F:  Skin/epidermis

– Fu:  outer  body  covering

• MELANOPHORE– O:  Neural  crest

– F:  Melanophore/chromatophores

– Fu:  secretes  melanin,  for  protecSon,  camouflage,  gives  color    

• EXTERNAL  NARES– O:  epidermal  ectoderm

– F:  external  nares

– Fu:  entrance  of  air

• EPIPHYSIS– O:  Neural  Tube– F:  Pineal  body/gland– Fu:  secretes  melatonin

• PROSENCEPHALON– O:  Neural  tube– F:  telen,  dien– Fu:  CNS

• PROSOCOEL– O:  Neurocoel– F:  1st  &  2nd  ventricles  of  cerebral  hemisphere

– Fu:  Communicates  with  olfactory  bulb  cavity;  CSF  passageway

• ANTERIOR  CHOROID  PLEXUS– O:  neural  tube– F:  Anterior  choroid  plexus– Fu:  Transport  of  CSF  to  brain  vesicles

• ORAL  SUCKERS– O:  Epidermal  ectoderm

– F:  disappears

– Fu:  adhesion  and  food  capture

• ORAL  CAVITY– O:  Rupture  of  oral  plate

– F:  Buccal  cavity

– Fu:  buccal  breathing  and  nutriSon

• STOMODEUM  DEPRESSION– O:  Epidermal  ectoderm

– F:  lining  of  mouth  cavity

– Fu:  covering  of  mouth  cavity

• INTERNAL  NARES– O:  epidermal  ectoderm

– F:  internal  nares

– Fu:  Passageway  of  air

• TELENCEPHALON– O:  Neural  tube

– F:  Telencephalon/cerebral  hemisphere

– Fu:  voluntary  movement,  consciousness,  sensaSons

• TELOCOEL– O:  neurocoel

– F:  1st  and  2nd  ventricles  of  cerebral  hemisphere

– Fu:  CSF  passageway  

• DIENCEPHALON– O:  Neural  tube– F:  thalamus,  hypothalamus,  diencephalon

– Fu:  Relay  staSon;  regulaSon

• DIOCOEL– O:  Neurocoel– F:  3rd  ventricle  of  telencephalon

– Fu:  communicates  with  lateral  ventricle  through  Foramen  of  Monro;  CSF  passageway

• OPTIC  CUP– O:  neural  tube

– F:  OpSc  cup

– Fu:  Regulates  light  entering  lens  

• RETINA– O:  Neural  tube

– F:  ReSna

– Fu:  has  rods  and  cones;  visual  receptor

• OPTIC  LENS– O:  Epidermal  ectoderm

– F:  Lens

– Fu:  Regulates  light;  light  refracSon

• PIGMENTED  EPITHELIUM– O:  Neural  tube

– F:  Pigmented  epithelium

– Fu:  Outer  covering  of  opSc  cup;  maintains  reSnal  environment

• OPTIC  NERVES  (II)– O:  Neural  crest

– F:  OpSc  nerves  (II)

– Fu:  innervates  the  eyes

• MESENCEPHALON– O:  Neural  tube

– F:  OpSc  lobes

– Fu:  Visual  center

• MESOCOEL– O:  Neurocoel

– F:  OpSc  vesicles;  aqueduct  of  sylvius

– Fu:  Connects  with  caviSes  of  opSc  lobes,  CSF  passageway

• INFUNDIBULUM– O:  Neural  tube

– F:  Posterior  pituitary  gland

– Fu:  Secretes  oxytocin  and  vastocin

• HYPOPHYSIS– O:  Neural  tube

– F:  Anterior  pituitary  gland

– Fu:  secretes  prolacSn  and  FSH  

• TRIGEMINAL  GANGLION– V

– O:  Neural  crest

– F:  Trigeminal  nerve  (V)

– Fu:  Innervates  the  jaw

• RHOMBENCEPHALON– O:  Neural  tube

– F:  Cerebellum  (metencephalon),  medulla  oblongata  (myencephalon)

– Fu:  Muscle  coordinaSon,  reflex  centers

• RHOMBOCOEL– O:  neurocoel

– F:  Rhombocoel

– Fu:  CSF  passageway

• BASAL  PLATE– O:  Neural  tube

– F:  cerebellum

– Fu:  Involuntary  coordinaSon

• POSTERIOR  CHOROID  PLEXUS– O:  Neural  tube  

– F:  Posterior  choroid  plexus

– Fu:  Transport  CSF  to  brain  vesicles

• ACOUSTICO-­‐FACIALIS  GANGLION  – VII  to  VIII

– O:  neural  crest

– F:  facial  (VII)  &  auditory  (VIII)  nerve

– Fu:  VII  –  innervates  taste  buds  and  facial  muscles;  VIII  –  innervates  utriculus  and  sacculus

• GLOSSOPHARYNGEAL  GANGLION– IX

– O:  Neural  crest

– F:  Glossopharyngeal

– Fu:  Innervates  the  tongue

• OTIC  VESICLE– O:  Epidermal  ectoderm

– F:  Inner  ear

– Fu:  Balance  and  equilibrium

• ENDOLYMPHATIC  DUCT– O:  Epidermal  ectoderm

– F:  Disappears

– Fu:  Forms  semi-­‐circular  canals

• SPINAL  CORD– O:  Neural  tube

– F:  Spinal  cord

– Fu:  sensory  and  motor  funcSons

– Ependymal  layer  -­‐>  ependymal  epithelium

– Mantle  layer  -­‐>  gray  ma^er

– Marginal  layer  -­‐>  white  ma^er

• CENTRAL  CANAL– O:  Neurocoel

– F:  Central  canal

– Fu:  CSF  passageway

• OLFACTORY  EPITHELIUM– O:  Epidermal  ectoderm

– F:  Olfactory  epithelium

– Fu:  ProtecSon

• OLFACTORY  CANAL– O:  Epidermal  ectoderm

– F:  Choanal  canal

– Fu:  Opens  into  pharynx  and  internal  nares;  respiraSon

ENDODERMIC  DERIVATIVES

Endode

Epitheli Epitheli Liver Pancrea Thyroid Parathy Thymus Lining   Urinary   gamete

• PHARYNX– O:  PrimiSve  Gut

– F:  Pharynx

– Fu:  DigesSon  and  respiraSon  pathway

• PHARYNGEAL  POUCH– O:  PrimiSve  Gut

– F:  Middle  ear,  eustachian  tube,  parathyroids

– Fu:  eustachian  tube  allows  equal  pressure;  secretes  parathyroid  hormones

• THYROID  GLAND– O:  endoderm

– F:  Thyroid  gland

– Fu:  Secretes  thyroxin

• ESOPHAGUS– O:  PrimiSve  gut

– F:  Esophagus

– Fu:  passageway  of  food  to  stomach

• TRACHEA– O:  PrimiSve  gut

– F:  Trachea

– Fu:  windpipes  for  air  passage

• EXTERNAL  GILLS– O:  Endoderm

– F:  Disappears

– Fu:  tadpole  respiraSon  

• LUNG  BUDS– O:  PrimiSve  gut

– F:  Lungs

– Fu:  RespiraSon

• STOMACH– O:  PrimiSve  gut– F:  Stomach– Fu:  enzymaSc  digesSon

• GALL  BLADDER– O:  PrimiSve  gut– F:  Gall  bladder– Fu:  Stores  bile

• LIVER– O:  PrimiSve  gut– F:  Liver– Fu:  secretes  bile,  removes  toxins

• NOTOCHORD– O:  Chordamesoderm

– F:  Disappears

– Fu:  PrimiSve  axial  skeleton  support

• MIDGUT– O:  Archenteron

– F:  duodenum,  ileum,  small  intesSne  

– Fu:  Main  site  of  digesSne

• YOLK  – O:  Endoderm

– F:  Disappears

– Fu:  Nourishment    before  external  gill  stage

• HINDGUT– O:  Archenteron

– F:  Hindgut

– Fu:  Further  digesSon

• CLOACA– O:  PrimiSve  gut

– F:  Cloaca

– Fu:  connects  LI  and  anus

• ANUS– O:  Blastopore

– F:  Anus

– Fu:  ExcreSon  of  waste  and  gametes

MESODERMAL  DERIVATIVES

Mesoderm

Epimere

Myotome

Skeletal  muscles

Sclerotome

Vertebral  column

Dermatome

Dermis  of  the  back

Mesomere

Nephrotome

Excretory  system

Gonadotome

Reproduc6ve  system  except  

Hypomere

Soma6c  mesoderm

Dermis Connec6ve  6ssues  &  

Splanchnic  mesoderm

Connec6ve  6ssues  of  

Heart&  blood  vessels

• PRECHORDAL  CARTILAGE– O:  Epimere

– F:  Chondrocranium

– Fa:  Movement  of  face,  head  and  neck

• BRANCHIOMETRIC  MUSCLES– O:  Epimere

– F:  Mouth  muscles

– Fu:  Movement  of  face,  head  and  neck

• HYPOBRANCHIAL  CARTILAGE– O:  Epimere

– F:  Visceral  skeleton

– Fu:  Supports  pharynx

• PARACHORDAL  CARTILAGE– O:  Epimere

– F:  Intranasal  plate

– Fu:  Supports  floor  of  cranium

• ANTERIOR  CARDINAL  VEIN– O:  Splanchnic  mesoderm– F:  Jugular  &  subclavian  veins

– J-­‐  drains  blood  from  tongue  and  lower  jaw;  S  –  drains  enSre  forelimb

• DERMATOME– O:  Epimere

– F:  Dermis

– Fu:  has  chromatophores  (for  color)

• MYOTOME– O:  Epimere

– F:  Appendicular  skeleton,  appendage  muscles,  skeletal  trunk  muscles

– Fu:  supports  the  body

• DORSAL  AORTA– O:  Splanchnic  mesoderm

– F:  Dorsal  aorta

– Fu:  Supplies  blood  to  lumbar  part  &  kidney

• EFFERENT  BRANCHIAL  VESSELS– O:  Splanchnic  mesoderm

– F:  Internal  caroSd;  2-­‐4  branchial

– Fu:  Curves  upward  to  visceral  arches

• AFFERENT  BRANCHIAL  VESSELS– O:  Splanchnic  mesoderm

– F:  external  caroSd;  2-­‐4  branchial

– Fu:  Emerges  from  truncus  arteriosus

• PERICARDIAL  CAVITY– O:  coelom

– F:  pericardial  cavity

– Fu:  surrounds  the  heart

• BULBOUS  ARTERIOSUS– O:  Splanchnic  mesoderm

– F:  conus  arteriosus

– Fu:  receives  blood  from  ventricle;  base  of  all  arteries

• TRUNCUS  ARTERIOSUS– O:  Splanchnic  mesoderm

– F:  Truncus  arteriosus

– Fu:  gives  off  external  caroSd,  receives  O2  rich  blood  from  conus  arteriosus

• PARIETAL  PERICARDIUM– O:  SomaSc  mesoderm

– F:  Parietal  pericardium

– Fu:  Separates  wall  from  cavity

• VISCERAL  PERICARDIUM– O:  Splanchnic  mesoderm

– F:  Parietal  pericardium

– Fu:  Separates  heart  from  cavity,  protects  &  holds  heart  in  place

• ATRIUM– O:  Splanchnic  mesoderm

– F:  right  and  leV  auricles

– Fu:  L  receives  blood  for  organs,  R-­‐lungs

• VENTRICLE– O:  Splanchnic  mesoderm

– F:  ventricle

– Fu:  pumps  blood  to  conus  arteriosus

• COMMON  CARDINAL  VEIN– O:  Splanchnic  mesoderm

– F:  precava

– Fu:  Enters  antero-­‐lateral  of  sinus  vein

• SINUS  VENOSUS– O:  Splanchnic  mesoderm

– F:  sinus  venosus

– Fu:  Pacemaker  for  heartbeat  regulaSon

• PRONEPHROS  KIDNEY– O:  Mesomere

– F:  mesonephros  kidney

– Fu:  filters  blood  in  tadpole

• POSTERIOR  CARDINAL  VEIN– O:  Splanchnic  mesoderm

– F:  Post  cava

– Fu:  enters  posterior  angle  of  sinus  venosus

• PRONEPHRIC  DUCT– O:  Mesomere

– F:  Mesonephric  duct

– Fu:  connects  primitve  kidney  to  cloaca

• PERITONEAL  CAVITY– O:  Coelom

– F:  Pleuro-­‐peritoneal  cavity

– Fu:  contains  most  internal  organs

• PARIETAL  PERITONEUM– O:  Soma6c  mesoderm– F:  Parietal  peritoneum,  smooth  muscle  of  gut

– F:  separates  wall  from  cavity

• VISCERAL  PERITONEUM– O:  Splanchnic  mesoderm– 3:  internal  caro6d,  4-­‐systemic  arch,  6  –  pulmocutaneous  artery

– Fu:  brings  blood  to  mouth,  brain,  tongue,  larynx,  jaw,  dorsal  esophagus,  orbit,  nose,  lungs,  skin  

• CAUDAL  ARTERY– O:  Splanchnic  mesoderm

– F:  Disappears

– Fu:  dorsal  aorta  porSon  that  passes  to  tail

• CAUDAL  VEIN– O:  Splanchnic  mesoderm

– F:  Disappears

– Fu:  Carries  blood  to  gills  to  be  oxygenated

THINGS  TO  REMEMBER

• Oh  oh  oh  to  touch  and  feel  a  girl’s  vagina  and  hymen

• Olfactory  (I),  OpSc  (II),  Oculomotor  (III),  Trochlear  (IV),  Trigeminal  (V),  Abducens  (VI),  Facial  (VII),  Auditory  (VIII),  Glossopharyngeal  (IX),  Vagus  (X),  Accessory  (XI),  Hypoglossal  (XII)

• Some  say  marry  money  but  my  brother  says  big  boobs  ma^er  most  (s  –  sensory,  m  –  motor,  b  –  both)    

REFERENCES/SOURCES

• Pics:  Mul6ply  sites  (hTp://trishatorga.mul6ply.com/photos/album/82  ,  hTp://buTercupadventures.mul6ply.com/photos/album/25/7mm-­‐tadpole-­‐embryo  ,  hTp://trish130.mul6ply.com/photos/album/27/Biology_12_Slides_Exercises_1-­‐3  ,  hTp://smickydoo.mul6ply.com/photos/album/200/7mm-­‐Tadpole-­‐Series-­‐Sec6on  )  +  bio  classmates  +  Bianca  de  la  Vega

• OTs  for  tadpole  info• Bio  12  manual• Sir  Fon6  notes