Early Development and Axis Formation in Amphibians

Question 1

The surface of the animal hemisphere will become the cells of the

Answer 1

ectoderm

Question 2

The vegetal hemisphere surface will form the cells of the

Answer 2

endorderm

Question 3

The internal cytoplasm around the equator will form the

Answer 3

mesoderm

Question 5

The general fate map is thought to be imposed by the transcription factor _ and the paracrine factor _

Answer 5

VegT and Vg1

Question 7

depleted the maternal VegT protein in early embryos

Answer 7

Zhang and colleagues (1998)

Question 8

If VegT is depleted, the animal third of the embryo produced only

Answer 8

ventral epidermis

Question 9

If VegT is depleted, the marginal cells, which normally produces mesoderm, generated

Answer 9

epidermal and neural tissue

Question 10

If VegT is depleted, the vegetal third, which usually produces endoderm, produced

Answer 10

mixture of ectoderm and mesoderm

Question 11

demonstrated that embryos that lacked functional Vg1 lacked endoderm and dorsal mesoderm

Answer 11

Joseph and Melton

Question 12

If Vg1 is not present, it will lack

Answer 12

endoderm and dorsal mesoderm

Question 13

Gastrulation in frog embryos is initiated on the, _, just below the equator in the region of the gray crescent.

Answer 13

future dorsal side of the embryo

Question 14

lines the archenteron as it forms

Answer 14

bottle cells

Question 15

Gastrulation in frog begins in

Answer 15

marginal zone

Question 16

zone surrounding the equator of the blastula, where the animal and vegetal hemispheres meet. This is where endodermal cells are not as large or as yolky as the most vegetal blastomeres

Answer 16

marginal zones