chapter 42: animal development and aging Flashcards
when does an oocyte complete meiosis II
after fertilization
what is cleavage
results in a multicellular embryo & is cell division without growth
what is morula
Formation of a solid ball of cells
what are blastula
dividing morula - hollow ball of cells
what is a blastocoel
a fluid-filled cavity in blastula
what is gas truly
germ layers form in part by invagination
what is the archenteron
primitive gut
what is the blastopore
opening into the primitive gut
what is the ectoderm
Nervous system; epidermis of skin and derivatives of the epidermis (hair, nails, glands); tooth enamel, dentin, and pulp; epithelial lining of oral cavity and rectum
what is the mesoderm
Musculoskeletal system; dermis of skin; cardiovascular system; urinary system; lymphatic system; reproductive system—including most epithelial linings; outer layers of respiratory and digestive systems
what is the endoderm
Epithelial lining of digestive tract and respiratory tract, associated glands of these systems; epithelial lining of urinary bladder; thyroid and parathyroid glands
what is the neural tube
: Tube formed by closure of neural groove. In vertebrates develops into spinal cord & brain
what is the somite
mass of mesoderm lateral to notochord in vertebrates; muscles associated with axial skeleton & vertebrae
what is the notochord
Cartilage-like supportive dorsal rod; replaced by vertebrae in vertebrates
what is the gut
formed by endoderm as body folds into tube