The Early Development of Vertebrates; Mammals

Question 1

oviduct is aka the

Answer 1

fallopian tube

Question 2

cleavage is the division of

Answer 2

blastomeres

Question 3

the division of blastomeres through rapid mitotic division is known as

Answer 3

cytokinesis

Question 4

when does cleavage begin?

Answer 4

18-24 hours after fertilization in the oviduct

Question 5

rotational cleavage is the

Answer 5

division in 2 planes

• meridian
• equatorial

Question 6

blastomeres do NOT divide in _________

this results in…

Answer 6

synchrony

odd numbers of cells

Question 7

what is driving/controlling the cleavage process?

Answer 7

genetic control of the diploid nucleus of the zygote

Question 8

abnormalities in the genome results in

Answer 8

cessation of mitosis & embryo development

leads to termination of pregnancy

Question 9

cadherins are

Answer 9

adhesion proteins

Question 10

compaction is the

Answer 10

tight bonding of blastomeres through cadherins

Question 11

compaction forms a

Answer 11

compact ball of cells

Question 12

what stabilizes the outer ring of cells in compaction?

Answer 12

tight junctions

Question 13

cell communication in compaction is established through

Answer 13

gap junctions

Question 14

define morula

Answer 14

solid ball of blastomeres forming @ 3 days post fertilization

Question 15

when does the human embryo exit the oviduct and enter the uterine space?

Answer 15

between the morula and blastocyst stage

Question 16

cavitation is

Answer 16

fluid secretion from the trophoblast to create a blastocoel

Question 17

during cavitation a sodium influx creates a ____________ environment drawing ____________ to the central part of the cell resulting in a _________ and the _________ stage

Answer 17

• hypertonic
• water
• blastocoel
• blastocyst

Question 18

the blastocyst stage is approximately day ___ in humans

Answer 18

5

Question 19

trophoblast is aka

Answer 19

trophectoderm

Question 20

define trophoblast

Answer 20

outer ring of cells that do NOT produce embryonic structures but lead to the formation of outer-embryonic membranes

Question 21

trophoblast adhere to ___________ which are attached to the _________________ of the uterine wall

Answer 21

• polysaccharides
• endometrial

Question 22

the polysaccharides are synthesized by…

these hormones are released from the…

Answer 22

estrogen & progesterone

corpus luteum

Question 23

The ICM are

Answer 23

embryonic stem cells that give rise to embryonic structures

Question 24

what kind of embryonic structures are made from the ICM

Answer 24

• allantois (bladder)
• amnion (embryonic sac)

Question 25

what encircles the developing embryo while in the fallopian tube?

Answer 25

the zona pellucida

Question 26

define hatching

Answer 26

breakdown of zona pellucida to expose the embryo

Question 27

what breaks down the zona pellucida?

Answer 27

- expanding blastocyst - enzymes from trophoblast

Question 28

contact between the trophoblast and the endometrium releases...

Answer 28

enzymes for burrowing and implantation within the uterine wall

Question 29

define gastrulation

Answer 29

organized cell movements within the embryo

Question 30

gastrulation produces

Answer 30

3 distinct germ layers known as the gastrula stage