DrG 29: 2 of 3 (Not MC)

the endoderm forms

the urinary bladder

during gastrulation

three germ layers are formed

the extraembryonic membrane that forms blood is the

yolk sac

a space opens within the inner cell mass that will form the

amniotic cavity

the mesoderm forms

muscle

ectoderm is to ____ as mesoderm is to _____

neural tissue; muscle tissue

the ectoderm forms

neural tissues

during implantation, the

syncytial trophoblast erodes a path through the endometrium

the solid ball of cells that has been likened to a mulberry is called a

morula

which of the following is one of the critical events of the first trimester

All of the above

under the influence of the trophoblast, maternal blood vessels in the endometrium

break down and form lacunae

the trophoblast has many of the characteristics of ___ cells

cancer

the mesoderm and trophoblast combine to form the

chorion

initially, the nutrients absorbed by the trophoblast easily reach the inner cell mass by simple

diffusion

the inner cell mass of the blastocyst will

form the embryo

by day 12 of embryonic development, mesoderm begins to form through

gastrulation

the placenta is a source of which of these hormones

hCG, relaxin, placental lactogen, and progesterone

a blastocyst is a

hollow ball of cells

all of the following are true of the allantois, except that

it acts as the fetal bone marrow

the region known as the primitive streak is the site of

migration of ectodermal cells to form the mesoderm