Wolpert; Cheryll Tickle; Alfonso Martinez Arias
9780198800569 Chapter 1-14 Complete Guide .
vertebral column - ANSWER: backbone or spine of vertebrates
antero-posterior axis - ANSWER: axis running from the head end to the tail end of the animal
dorso-ventral axis - ANSWER: the body axis running from the upper surface (back) to the under
surface (ventral) of an organism or structure
body plan - ANSWER: overall organization of an organism
neurulation - ANSWER: process in which the future brain and spinal cord are formed from the
ectodermal neural plate
ectoderm - ANSWER: embryonic germ layer that gives rise to the epidermis and the nervous system
mesoderm - ANSWER: germ layer that gives rise to the skeleto-muscular system, connective tissues,
blood, kidneys, and heart
endoderm - ANSWER: embryonic germ layer that gives rise to the gut and associated organs, such as
lungs and liver
organizer - ANSWER: a signaling center that directs the development of the whole embryo or part of
the embryo
gastrulation - ANSWER: process in animal embryos in which prospective endodermal and mesodermal
cells move from the outer surface of the embryo to the inside to form internal organs
phylotypic stage - ANSWER: stage at which the embryos of the different vertebrate groups closely
resemble each other
neural tube - ANSWER: the ectodermally derived tubular structure that forms along the dorsal midline
of a vertebrate embryo that gives rise to the nervous system through the process of neurulation
notochord - ANSWER: Transient rod-like mesoderm in vertebrate embryos that runs from head to tail
and lies centrally beneath the neural tube
somites - ANSWER: blocks of mesoderm that segment from the mesoderm on either side of the
notochord; give rise to trunk, limb muscles, ribs, and dermis
extra-embryonic membranes - ANSWER: membranes external to the embryo proper that are involved
in its protection and nutrition (amnion, chorion, placental tissues)
placenta - ANSWER: a structure that forms in the uterine wall at which the blood systems of mother
and embryo form an interface with each other
animal region - ANSWER: in egg of amphibians, the hemispherical end of the egg where the nucleus
resides, away from the yolk
vegetal region - ANSWER: yolky lower hemisphere of amphibian eggs and blastulas, from which the
endoderm will develop
vitelline membrane - ANSWER: extracellular layer surrounding the eggs of animals