The First Week (Exam 1)

Question 1

How many sperm will fertilize a secondary oocyte

Answer 1

1

Question 2

Will the oocyte lose the zona pellucida when ovulated

Answer 2

no

Question 3

What is the corona radiata a remnant of

Answer 3

follicular cells that surround the oocyte

Question 4

What is the first thing that the sperm will interact with during fertilization

Answer 4

corona radiata

Question 5

How will the sperm get through the corona radiata

Answer 5

dump enzymes from its acrosome to penetrate this layer

Question 6

What is the next step in fertilization after the sperm has penetrated corona radiata

Answer 6

has to cross the zona pellucida

Question 7

Binding to the zona pellucida is what

Answer 7

species specific

Question 8

After the sperm crosses through the zona pellucida, what occurs

Answer 8

the zona reaction

Question 9

What is the zona reaction

Answer 9

the oocyte will release enzymes from lysosome that will block other sperm from entering

Question 10

What occurs after the zona reaction

Answer 10

sperm has to cross plasma membrane

Question 11

What will occur as a response to fusion of the sperm and oocyte cytoplasms

Answer 11

cortical reaction

Question 12

What does the cortical reaction result in

Answer 12

preventing further sperm from entering to ensure that only one sperm fertilizes an oocyte

Question 13

When will the second meiotic division of an oocyte occur

Answer 13

after fertilization

Question 14

When sperm cell membrane dissociates, what does the sperm form

Answer 14

male pronuclei

Question 15

What does the oocyte form in response to the male pronuclei

Answer 15

female pronuclei

Question 16

After fertilization, when will the first division occur

Answer 16

when the male pronucleus is broken down

Question 17

What are the flow of events that occur during fertilization

Answer 17

sperm passes through corona radiata

binding to zona pellucida (zona reaction occurs)

fusion of oocyte and sperm plasma membrane (cortical reaction occurs)

second meiotic division of oocyte and formation of male and female pronuclei

Question 18

What are the results of fertilization

Answer 18

restoration of a diploid genome

genetic sex of the embryo is identified

cleavage is initiated

Question 19

How do contraceptive pills work

Answer 19

contain estrogen and progesterone

inhibit the secretion of FSH and LH from pituitary, blockign follicle maturation and ovulation

effects on the uterus include reduced endometrial proliferation and secretion of thick cervical mucus

Question 20

What birth controls will alter the progesterone curve

Answer 20

Depo, Plan B, RU-486

Question 21

What is Depo-provera

Answer 21

progesterone analog

Question 22

What is Plan B

Answer 22

Levonorgestrel

Question 23

What is RU 486

Answer 23

an antiprogesterone

Question 24

What changes occur to the zygote the first week after fertilization

Answer 24

-cleavage
-no growth in size
but increase in cell number
-remains in zona pellucida

Question 25

Where do the cell divisions occur during cleavage

Answer 25

as the cell transverses the uterine tube

Question 26

What are the small cells in cleavage called

Answer 26

blastomeres

Question 27

What is a morula

Answer 27

once the cell has 16-32 cells | raspberry shaped ball of cells

Question 28

What occurs during compaction

Answer 28

cells get closer together and increase cell contact increase number of gap junctions between cells nucleus is shifted to the center (determines polarity)

Question 29

When is the blastocyst formed

Answer 29

First week

Question 30

How is the blastocyst formed

Answer 30

cells begin to cluster on one side of the cell and around the outside edges (creates outside cells and inner mass)

Question 31

What are the different parts of the blastocyst

Answer 31

Inner cell mass Outer cell mass Blastocyst cavity

Question 32

What is the inner cell mass called in a blastocyst

Answer 32

embryoblast

Question 33

What is the outer cell mass called in a blastocyst

Answer 33

trophoblast

Question 34

What is the time it takes from ovulation to implantation

Answer 34

6-7 days

Question 35

What type of epithelium will surround an embryo after implantation

Answer 35

uterine epithelium will invade and be enclosed by

Question 36

What is an ectopic pregnancy

Answer 36

pregnancy that occurs anywhere but the uterus

Question 37

What are the risks of an ectopic pregnancy

Answer 37

high risk for rupture and death

Question 38

What is placenta previa

Answer 38

abnormal placental implantation within the cervix

Question 39

Are placenta previa pregnancies viable

Answer 39

yes

Question 40

What is placental abruption

Answer 40

the placenta detaches from the uterus

Question 41

What are the risks of placental abrupton

Answer 41

increased bleeding risks for mom | loss of blood supply to baby

Question 42

What is placental accreta

Answer 42

when the placenta overgrows, takes over, the embryo does not develop

Question 43

What are the risks to mom with placental accreta

Answer 43

bleeding risk

Question 44

How long can sperm survive for

Answer 44

48 hours

Question 45

the ovulated oocyte is only viable for how many hours

Answer 45

24 hours

Question 46

Where does fertilization occur in the uterine tube

Answer 46

ampulla

Question 47

Of the 300 million sperm deposited into the female reproductive tract how many make it to the egg

Answer 47

0.0001%

Question 48

Passageway of the sperm through the corona radiata occurs through what reaction

Answer 48

acrosome reaction

Question 49

How does the sperm cross the zona pellucida

Answer 49

releasing more acrosome enzymes

Question 50

Fusion of the sperm to the oocyte causes what

Answer 50

the zona reaction

Question 51

What does the zona reaction result in

Answer 51

altering the sperm receptors and prevents additional sperm from binding to the zona pellucida

Question 52

Fusion through the plasma membrane results in what reaction

Answer 52

cortical reaction

Question 53

What occurs during the cortical reaction

Answer 53

oocyte releases lysosomal contents to make membrane impenetrable to other sperm

Question 54

What occurs during growth of pronuclei

Answer 54

replication of DNA

Question 55

What is the name of an oocyte with two pronuclei

Answer 55

ootid

Question 56

What is EPF

Answer 56

Early Pregnancy Factor

Question 57

What is early pregnancy factor secreted by

Answer 57

trophoblast cells and appears in maternal blood 24-48 hours after fertilization

Question 58

What can EPF used for

Answer 58

pregnancy tests during first 10 days

Question 59

When does cleavage start in a zygote

Answer 59

within 24 hours

Question 60

When does compaction occur

Answer 60

after 3 divisions

Question 61

The cells of the morula give rise to what

Answer 61

all membranes and the fetal placenta

Question 62

When does the morula enter the uterine cavity

Answer 62

day 4

Question 63

What causes the morula to become a blastocyst

Answer 63

by taking up fluid and forming a blastocyst cavity

Question 64

What events occur during implantation

Answer 64

dissolution of the zona pellucida adhesion of blastocyst onto endometrium trophoblastic penetration and spread into endometrium migration of blastocyst into endometrium

Question 65

What percent of pregnancies result in ectopic pregnancies

Answer 65

2%

Question 66

where do 95% of ectopic pregnancies occur

Answer 66

in the uterine tube

Question 67

What percentage of zygotes, morulae, and blastocysts spontaneously abort

Answer 67

45%