Lecture 3 - Differentiation and Neural Induction III

Question 1

DNA methylation (paternal vs maternal)

Answer 1

rapid, active demethylation of paternal genome, passive of maternal genome

Question 2

blastula

Answer 2

first divisions of the zygote > spherical cluster of cells with a fluid filled space in the center

Question 3

blastomeres

Answer 3

individual cells in blastula

Question 4

blastocoel

Answer 4

the hollow space within the blastula; gets smaller the more the embryo grows

Question 5

gastrula

Answer 5

the embryo starts forming the primitive gut

Question 6

gastrulation (definition)

Answer 6

process by which the blastula forms the primitive gut, 3rd week

Question 7

gastrulation end products

Answer 7

formation of the germ layers: ectoderm, mesoderm, endoderm

Question 8

gastrulation process

Answer 8

blastopore forms, cells move in

Question 9

blastoderm

Answer 9

layers that form blastula

Question 10

amphibian embryonic development

Answer 10

zygote > blastula > blastopore > gastrula

Question 11

mesoderm becomes…

Answer 11

notochord (sends signals to ectoderm)

Question 12

ectoderm becomes…

Answer 12

CNS, neural crest cells

Question 13

morula (3 day)

Answer 13

fertilized egg divides to form a ball

Question 14

blastocyst (4 days)

Answer 14

morula becomes hollow

Question 15

trophoblast

Answer 15

outer cells of blastocyst, placenta

Question 16

experiment with trophoblast

Answer 16

injecting labelled cell into the center becomes inner mass cells, periphery - trophoblast

Question 17

inner cell mass

Answer 17

clump of cells found in blastula, some give rise to the body the remainder the placenta and tissues for prenatal growth

Question 18

epiblast

Answer 18

closer to trophoblast, faces embryonic cavity

Question 19

hypoblast

Answer 19

faces the blastocoel

Question 20

beginning of gastrulation

Answer 20

ICM forms a disc 2 layers thick inside the embryo (epiblast, hypoblast)

Question 21

primitive streak

Answer 21

forms in epiblast

Question 22

formation of mesoderm and ectoderm

Answer 22

invagination at primitive streak, cells come inside, hypoblast replaced by endoderm and more cells go in the middle to become mesoderm; cells that stay on top = ectoderm (end of gastrulation)

Question 23

amniotic cavity

Answer 23

above epiblast

Question 24

notochord

Answer 24

rod like structure formed after mesodermal tissue migrates to the midline; leads to neurulation

Question 25

neural plate

Answer 25

NS begins as an elongated layer of ectodermal cells on the surface

Question 26

neural groove

Answer 26

sides of the neural plate rise up to form the walls

Question 27

neural tube

Answer 27

walls of the neural groove eventually meet and fuse at the midline

Question 28

neural crest

Answer 28

at the peak of the two sides of neural groove; separate from the tube and ectoderm that forms over the neural tube; gives rise to PNS

Question 29

epidermis

Answer 29

formed by the outermost layer of the ectoderm

Question 30

neural tube gives rise to…

Answer 30

brain and spinal cord (CNS)

Question 31

neurula

Answer 31

embryo once NS appears

Question 32

neurulation

Answer 32

process by which a gastrula transforms into a neurula