Choose the best answer

1			An egg surrounded by a granulosa layer is most likely from a
			A)	sea urchin.
			B)	human.
			C)	frog.
			D)	fruit fly.
2			The first thing a sea urchin sperm encounters when it makes contact with the egg is the
			A)	plasma membrane.
			B)	vitelline membrane.
			C)	jelly coat.
			D)	zona pellucida.
3			Holoblastic cleavage results in
			A)	formation of a symmetrical blastula composed of cells of approximately equal size.
			B)	formation of an asymmetrical blastula composed of cells of approximately unequal size.
			C)	cell division of only the cells near the animal pole.
			D)	cell division of only the cells near the vegetal pole.
4			If the trophoblast layer failed to form in a mammalian embryo, which of the following structures would not develop?
			A)	the blastopore
			B)	the inner cell mass
			C)	the archenteron
			D)	the fetal placenta
5			Which forms first during gastrulation of a frog embryo?
			A)	mouth
			B)	anus
			C)	dorsal lip
			D)	gut
6			Gastrulation in mammals and birds is similar in that
			A)	cells migrate over the dorsal lip to generate the archenteron in the anterior hemisphere of the embryo.
			B)	cells migrate inward from the upper layer of the blastodisc to form the mesoderm.
			C)	cells migrate outward from the upper layer of the blastodisc to form the mesoderm.
			D)	cells migrate inward from the lower layer of the blastodisc to form the mesoderm.
7			Neural crest cells break off from the ______________ and later move to the sides of the developing embryo.
			A)	placodes
			B)	ectoderm
			C)	notochord
			D)	neural tube
8			The cells of the Spemann organizer are responsible for
			A)	notochord development.
			B)	cell transplantation.
			C)	dorsal lip formation.
			D)	development of the eye through an induction mechanism.
9			All of the following structures are derived from the mesoderm except
			A)	muscles.
			B)	the liver.
			C)	gonads.
			D)	blood vessels.
10			Most fetal growth occurs in
			A)	the first trimester.
			B)	the second trimester.
			C)	the third trimester.
			D)	the postnatal period.