Lecture 3 Flashcards
what are the steps of life history
Fertilization , embryonic development and maturation
what is fertilization ?
when the egg and sperm unite
After fertilization what happens next?
Zygote ( meaning that the egg is fertilized)
What are the patters of cleavage?
Holoblastic, meroblastic, radial and spiral
What is Holoblastic?
biotic furrow passes successfully though the entire zygote from animal to vegetal pole
Meroblastic?
biotic furrow does not go through the entire zygote
Spiral?
not going into deep
Radial
cutting it in every direction they will look the same
Morula
collection of cells
Blastula:
Big hollow ball of cells
what is surrounding the blastocoel?
blastomere
what is gastrulation?
Gut formation
what consist to rearrangement?
the moving of cells moving around
What is different from protostome and deuterstomes
the formation of the blastopore being the mouth or the anus
what consist of defferneiation
cells moving around to specialize to specific function
What does cell movement due during gastrulation?
Epiboly: a layer of tissue covering the outside of the cell
Invagination: ( indentation of w alls) epithelial tissue bends inward
Ingression: cells leave an epithelial sheet by transforming from well behaved epithelial cell to a freely migrating mesenchyme cell.
Involution: tissue sheet rolls inward to form underlay-layer
what are the differentiation germ layers?
ectoderm, mesoderm, and endoderm
what is the endoderm
it is the gut ( digestive tract)
Mesoderm what is it
Muscle, skeletal, some organs and connective tissue
mesoderm forms this which are referred a clumps ?
somites
Dermatome?
area of skin that is mainly supplied by a single spinal nerve
Myotome
give rise to the skeletal musculature
sclerotome
give rise to the the vertebrae
Mesenchyme
give rise to connective tissue
what is ectoderm
rise to the skin and nervous system,
What is neurulation?
formation of neural plate and nerucoel
primary neuralation
creates neural folds which meet in the middle and it is what creates our brain and nervous tissue
Secondary neurlation
neural keel
what are neural crest cells?
they contribute to multiple organs and unique to vets
Ectodermal placodes
sensory neves are of thickening
Ontogeny
development of human body
metamorphosis
a fast way in which an organism changes
heterochrony
changes of the rate of eveelopment compared to your ancestors
persmorphosis
features that are exaggerated compared to your ancestors
paedomorphosis
retention of juvenile characteristics
