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Question 1

what happen in 1st week in human development?

Answer 1

fertilization
cleavage
implantation

Question 2

how fertilization begins and ends ?

Answer 2

B with sperm and oocyte

E with the intermingling of maternal and paternal chromosomes at metaphase of the first mitotic division of the zygote a unicellular ebmro

Question 3

in which phase do maternal and paternal cheomosomes intermilate?

Answer 3

metaphase of the 1st mitotic division of zygote

Question 4

phases of fertilization :

Answer 4

passage of sperm through the corona radiata

Penetration of the zona pellucida
• Fusion of cell membranes of the oocyte and sperm
• Completion of the second meiotic division of the
oocyte and formation of the female pronucleus
• Formation of the male pronucleus.
• Oocyte with two haploid pronuclei is called ootid
• Pronuclei fuse into a single diploid aggregation of
chromosomes
• Ootid becomes Zygote

Question 5

sperm cell penetrate /////

Answer 5

the zona pellucida

Question 6

when the oocyte division complate ?

Answer 6

after fusion of cell membarnes of the oocyte and sperm

Question 7

oocyte with 2 haploid pronuclei is called

Answer 7

ootid

Question 8

when ootid become zygote?

Answer 8

pronuclei fuse into a single diploid aggregation of chromosmoe

Question 9

when the second division is complated ?

Answer 9

when oocyte penetrated

Question 10

what initiates cleavage of the zgote ?

Answer 10

fertilization

Question 11

Fertilization of the oocytes and cleavage of the
zygotes are monitored microscopically for

Answer 11

3 to 5 days

Question 12

when the sperm enzymes are not fertilized enough they use ?

Answer 12

intracytoplasmc sperm injection

Question 13

cleavage consists of ?

Answer 13

repeated mitotic division of the zygote

Question 14

cells during cleavage are called ?

Answer 14

blastomeres

Question 15

Division of the zygote into blastomeres
begins approximately

Answer 15

30 hours after fertilization

Question 16

The period of the morula
begins at the

Answer 16

12-16 cell stage

Question 17

the blastocyst
start to enlarge
considerably

Answer 17

after the zona pellucida degenerates

Question 18

inner cell mass

Answer 18

embryoblast

Question 19

outer cell mass

Answer 19

trophoblast

Question 20

when the blastocyst
attaches to the endometrial epithelium?

Answer 20

6 days after fertization
day 20 of 28 day menstrual cycle

Question 21

the
blastocyst is superficially implanted in the
endometrium

Answer 21

by the end of 1st week

Question 22

trophoblast inner layer
outer layer

Answer 22

cytotrophoplast
syncytiotrophoblast

Question 23

extend through the endometrial epithelium and invade the
connective tissue

Answer 23

finger-like processes of syncytiotrophobl

Question 24

layer of cells, the
hypoblast (primary endoderm), appears on the surface of the embryoblast facing
the blastocystic cavity
• By the end of the first

Answer 24

At approximately d7