Vertebrate Development: Frogs

Question 1

Zygote

Answer 1

Single fertilized egg cell

Question 2

Cleavage

Answer 2

Zygote rapidly divides again and again to form the morula (cleavage)

Question 3

Morula

Answer 3

Solid ball of cells (cleavage)

Question 4

Animal Pole

Answer 4

Side of the zygote/morula that contains less yolk (top) and has smaller cells (little yolk to slow down division)

Question 5

Vegetal Pole

Answer 5

Side of the zygote/morula that contains more yolk (bottom) and has bigger cells (yolk slows down division)

Question 6

Blastula Formation

Answer 6

Cells continue to divide until the blastula is formed (blastula formation)

Question 7

Blastula (Coeloblastula)

Answer 7

Hollow ball of cells (blastula formation)

Question 8

Blastocoel

Answer 8

Hollow space inside the blastula lined by all 3 embryonic germ layers (blastula formation)

Question 9

Gastrulation

Answer 9

Cells from the outer surface migrate inward and anterior through the blastopore (gastrulation)

Question 10

Blastopore

Answer 10

Posterior opening (gastrulation)

Question 11

Yolk Plug

Answer 11

Patch of vegetal cells (endoderm) that remains exposed in the blastopore after the formation of the ventral lip (gastrulation)

Question 12

Formation of 3 Embryonic Germ Layers

Answer 12

Ectoderm, mesoderm, and endoderm (gastrulation)

Question 13

Archenteron

Answer 13

New space lined with endoderm that forms within the embryo and gives rise to the lumen (gastrulation)

Question 14

Lumen

Answer 14

Space inside the digestive tract

Question 15

Blastocoel Displacement

Answer 15

Blastocoel is completely displaced by the archenteron (gastrulation)

Question 16

Gastrulation Directionality

Answer 16

Posterior and anterior becomes ventral and dorsal (gastrulation)

Question 17

Neurulation

Answer 17

Formation of the neural tube, notochord, coelom, and 3 mesoderm regions

Question 18

Neural Plate Formation

Answer 18

1. Cells of the notochord release proteins
2. These signal to the ectoderm located dorsal to the notochord
3. Signal induces ectoderm to differentiate into the neural plate ectoderm
   (neurulation)

Question 19

Neural Plate Ectoderm

Answer 19

Bends along the dorsal midline to form the neural folds and the neural groove (neurulation)

Question 20

Neural Folds

Answer 20

Fuse together to form the hollow neural tube (neurulation)

Question 21

Neural Tube

Answer 21

Hollow tube that gives rise to the central nervous system (brain and spinal cord) (neurulation)

Question 22

Neurocoel

Answer 22

Hollow cavity in the neural tube that becomes the ventricles of the brain and the central canal of the spinal cord (neurulation)

Question 23

Neural Crest Cells

Answer 23

Mesenchymal cells that migrate throughout many regions of the embryo and separate from the dorsal region of the neural tube during neurulation (neurulation)

Question 24

Epidermal Ectoderm

Answer 24

Moves towards midline to cover the neural tube (neurulation)

Question 25

Notochord

Answer 25

Derived from mesoderm (neurulation)

Question 26

Coelom

Answer 26

Hollow space that forms between the somatic hypomere mesoderm and the splanchnic hypomere mesoderm and gives rise to major body cavities of the adult (neurulation)

Question 27

Mesenchymal Cells

Answer 27

Cells shed from different regions of mesoderm that can migrate independently throughout the embryo (various times during development)

Question 28

Epimere Mesoderm

Answer 28

Upper region of mesoderm that forms somites in the trunk region (neurulation)

Question 29

Somites

Answer 29

Differentiate into dermatome, myotome, and sclerotome

Question 30

Mesomere Mesoderm

Answer 30

Middle region of mesoderm (neurulation)

Question 31

Hypomere Mesoderm

Answer 31

Lower region of mesoderm that further differentiates into somatic hypomere mesoderm and splanchnic hypomere mesoderm (neurulation)