Development and Inheritance

Question 1

What happens during fertilization?

Answer 1

genetic material of sperm and oocyte merge into a single nucleus

Question 2

When does fertilization occur?

Answer 2

12-24 hours after ovulation

Question 3

What must happen before fertilization can occur?

Answer 3

capacitation

acrosomal reaction

Question 4

what is capacitation?

Answer 4

weakening of cell membrane of spermatozoa head

Question 5

where does capacitation happen?

Answer 5

female reproductive system

Question 6

what is the acrosomal reaction?

Answer 6

sperm surrounds oocyte and releases hyaluronidase

Question 7

what happens after hyaluronidase is secreted?

Answer 7

disruption of the corona radiate and the zona pellucida

Question 8

what blocks polyspermy?

Answer 8

changing the location of the veils

Question 9

what is polyspermy?

Answer 9

many sperm

Question 10

How long do spermatozoa survive?

Answer 10

3-7 days

Question 11

How long is the oocyte viable once ovulated?

Answer 11

24 hours

Question 12

What day of the cycle should fertilization occur?

Answer 12

day 15

Question 13

What happens when sperm enters the secondary oocyte?

Answer 13

fusion of male pronucleus and female pronucleus

Question 14

what is a male pronucleus?

Answer 14

flagella is shed and head develops

Question 15

what is a female pronucleus?

Answer 15

nucleus of female oocyte

Question 16

What happens when the male pronucleus and female pronucleus fuse?

Answer 16

a zygote is formed with 46 chromosomes

Question 17

How are dizygotic twins formed?

Answer 17

when the mother ovulates 2 oocytes and both are fertilized

Question 18

Once a zygote is formed, it will undergo

Answer 18

a form of mitosis called cleavage

Question 19

what is cleavage?>

Answer 19

1 celled zygote will duplicate and split into two cells

Question 20

How long after fertilization does cleavage occur?

Answer 20

30 hours

Question 21

what follows cleavage?

Answer 21

more and more cell division until a morula is formed

Question 22

what is a Morula?

Answer 22

solid ball of blastomeres surrounded by the zona pellucida

Question 23

Where is the morula?

Answer 23

fallopian tube headed for the uterus

Question 24

What happens after 5 days of development?

Answer 24

a blastocyst is formed.

Question 25

what is a blastocoele?

Answer 25

cavity that forms in the middle of the blastocyst

Question 26

what is a trophoblast?

Answer 26

outer covering of cells on the blastocyst

Question 27

what causes blastocoele?

Answer 27

movement of blastomeres

Question 28

what is the embryoblast?

Answer 28

inner covering of cells on a blastocyst

Question 29

the embryoblast will form the

Answer 29

baby

Question 30

the trophoblast will become

Answer 30

the placenta

Question 31

how are monozygotic twins developed?

Answer 31

1 oocyte is fertilized by 1 sperm but 2 areas of embryoblast develop individually

Question 32

what are conjoined twins?

Answer 32

monozygotic twins that are joined physically

Question 33

what causes conjoined twins?

Answer 33

abnormal cleavage

Question 34

When does the blastocyst enter the uterus?

Answer 34

5 days after fertilization

Question 35

what happens 6-7 days after fertilization?

Answer 35

blastocyst attaches to endometrium

Question 36

what is the germinal period

Answer 36

first two weeks when the germ layers will form

Question 37

what is the embryonic period?

Answer 37

3-8 weeks of development

Question 38

what happens after the embryonic period?

Answer 38

fetal period

Question 39

What are the three germ layers that the embryoblast differentiates into?

Answer 39

ectoderm mesoderm endoderm

Question 40

what is the ectoderm?

Answer 40

outside layer. skin and nervous system

Question 41

what is the mesoderm?

Answer 41

middle layer. muscle, bone and connective tissue

Question 42

what is the endoderm?

Answer 42

middle layer. most viscera

Question 43

what are the four membranes that develop

Answer 43

yolk sac amnion chorion allantois

Question 44

what is the yolk sac?

Answer 44

early site of blood formation. comes from the endoderm

Question 45

what is the amnion?

Answer 45

membrane that surrounds embryo

Question 46

what fills the amnion?

Answer 46

amniotic fluid

Question 47

where does the amnion come from?

Answer 47

ectoderm

Question 48

what is the function of the amnion?

Answer 48

protection

Question 49

what is the chorion?

Answer 49

membrane that becomes pportion of the placenta

Question 50

what does the chorion secrete?

Answer 50

human chorionic gonadotropin

Question 51

what is the function of hCG?

Answer 51

continue progesterone secretion

Question 52

what are pregnancy tests based on?

Answer 52

human chorionic gonadotropin detection

Question 53

where does the chorion come from?

Answer 53

trophoblasts

Question 54

what is the allantois?

Answer 54

early site of blood formation

Question 55

where does the allantois come from?

Answer 55

endoderm

Question 56

what is the function of the placenta?

Answer 56

bringing oxygen and removing waste products

Question 57

what happens to the placenta after 3-4 months?

Answer 57

production of progesterone and estrogen

Question 58

what do progesterone and estrogen do?

Answer 58

maintain endometrial lining and prepare mammary glands for milk

Question 59

what is the function of the chorion?

Answer 59

to grab onto the mother

Question 60

when can hCG be detected on a pregnancy test?

Answer 60

day 22

Question 61

what is gestation?

Answer 61

time that a zygote, embryo or fetus is carried in the reproductive tract

Question 62

How long is the human gestation period

Answer 62

266 days or 40 weeks

Question 63

what is labor proceeded by?

Answer 63

increase in hormones

Question 64

what are the three stages of labor?

Answer 64

stage of dilation stage of expulsion placental stage

Question 65

what is stage of dilation

Answer 65

dilation of the cervix from 1 to 10 cm

Question 66

what happens during the stage of dilation?

Answer 66

contractions of the uterus and rupturing of the embryonic sac

Question 67

what is the stage of expulsion?

Answer 67

when delivery occurs

Question 68

how long does the stage of dilation last?

Answer 68

hours

Question 69

how long is the stage of expulsion?

Answer 69

minutes

Question 70

what is the placental stage?

Answer 70

when the placenta is passed

Question 71

how long is the placental stage?

Answer 71

minutes