Developmental / Embryology Flashcards
Alveolar cells arise from A endoderm B mesoderm C ectoderm D ecto and endodrrm
Answer is endoderm
Why? Endoderm is epithelial lining of the respiratory system
Mesoderm does the cartilidge, smooth muscle and endothelium
what happens in the Cortical reaction?
Exocytosis of cortical granules to release digestive enzymes on Zona pellucida preventing more sperm from binding
> hardens ZP, removed the ZP3 which has the recognition membrane
Gastrualation
movement of germ layers relative to one another e.g. forming animal and vegetal poles, and patterning
What does the acrosome of sperm contain?.... A lysozymes B hyaluronidase C proteases D abscasic acid
B
Contact with the zona pellucida triggers acrosomal reaction (release of enzymes via calcium mediated exocytosis)
> GALT recognises NAG on ZonaP3
What is the correct order for animal development stages?
A fertilisation, gastrulation, cleavage, neurulation, organogeneis
B fertilisation, cleavage, gastrulation, neurulation, organogeneis
C fertilisation, cleavage, neurulation, organogeneis, gastrulation
D fertilisation, cleavage, neurulation, gastrulation, organogeneis
Fcgno
Option B
Cleavege from blastula,
Role of cytoplasmic determinants
A prevent additional implantation of egg
B produce polar and nonpolar daughter cells
C determine the components of embryonic cell cytoplasm
D influence gene expression therefore affect the developmental fate of cell
D
Helps to make daughter cells different to each other, crucial for development
E. G. Emergence of pattern, morphogenesis, growth and potency
What potency is a zygote A pluripotent B totipotent C unipotent D oligopotent
B
Can make the extra embryonic tissues (placenta)
What type of molecule is GSK-3 binding protein? A transcription factor B TGFbeta signalling factor C kinase inhibitor D homeobox gene
C
It inhibits protein kinase GSK-3 which allows beta-catenin to be stabilised in dorsal cells (as part of Wnt signalling)
> beta catenin can activate target gene expression
> GSK3b KINASE degrades beta catinin unless inhibited!
In spematogensis, what stage of the cell cycle are primordial germ cells arrested /frozen in?
G1
after birth, diploid spematoGOnia mitosis to spematoCYTES and meiosis to TIDS
and then differentiate to mature ZOA/sperm
> meosis before differentiation
In oogenesis, what stage of the cell cycle are primordial germ cells arrested /frozen in? A G2 B mitosis anaphase C meiosis prophase 1 D meoisis anaphase 1 E meosis metaphase 2
Prophase of meiosis 1 as primary oocytes
as adult they get larger and mature and in ovulation completed meosis 1!
> secondary oocyte frozen in metaphase 2 and in fertilisation meosis 2 is completed!
the nervous system arises from which germ layer?
the ectoderm layer! (so does the skin)
what is meant by ‘‘growth by accretion’’?
this means bone or shell is growing as the embryo grows. other ways of developmental growth are
> cell proliferation
> cell enlargement
what would hapen if the embryo (with apical surfaces) undegoes tangential divison?
the daughter cells would be differet. one polarised and one not
embryo name changes
blastomere(8 cells) to morula (3 days) to a blastocyst with a fluid filled cavity (blastocoel)
sperm name changes
spermatoagonia
spermatocyte
spermatotid
spermatazoa ( mature sperm)
egg name changes
oogonia / primordial oocyte??…
primary oocyte
secondary oocyte
ovum/egg + 2 polar bodues
what does the trophectoderm and inner cell mass create?
T = extra embryonic tissue ICM = embryo proper/ main body == embryoblast
What is importance of calcium in cortical reactiob
Degrades cyclin - - > Metaphase 2 lifted in secondary oocyte in ovulation
this allows meosis of oocyte complete!!
> essential for intitiating embryo developement
what triggers the cortical reaction?
the (2nd) recognition event of transmembrane proteins
Izumo + Juno transmembrane proteins that recruits oocyte protein CD9 allowing membranes to fuse
>sperm entry triggers the calcium ossilations release –> exocytosis of cortical granule
what is the first fluid filled cavity to form during embryoinci delevopemnt A amniotic cavity B blastomere C archenteron D blastocoel E epiblast
OPTION D
blastomere is a single cell
the primary gut that forms during gastrulation in the developing zygote is known as the archenteron/ digestive tube. It develops into the endoderm and mesoderm of an animal
the muscle is from which germ layer?
the Mesoderm
> m for muscle haaha
what does the inner cell mass split into?
epiblast - embryo proper/3 germ layers
hypoblast - furthur extraembryonic structures
What does the endoderm develop into in vertebrates A Gut, lungs and liver B Muscles, blood and hearth C Nervous system and epidermis A Skeleton and kidney
OPTION A
The endoderm develops into the gut, lungs and liver in vertebrates, and just the gut in insects.
Which of these statements is incorrect in fertilisation?
A Hyaluronidase activity on sperms head allows it to penetrate the cumulus layer
B Change in membrane potential opens voltage gated calcium channels, increasing intracellular Ca2+, triggering the acrosome reaction
C Sperm protein ‘Izumo’ recognises oocyte protein ‘juno’ recruiting CD9, causing the the plasma membranes to fuse
D Sodium release within the oocyte triggers completion of the second meiotic division and the cortical reaction
E Lytic enzymes from the cortical granules partially digest ZP2, and remove carbohydrate from ZP3, hardening the zone pellucid, preventing polyspermy
OPTION D
> calcium not sodium release (activates kinase that degrades cyclin lifting metaphase 2)
