Embryology/Pregnancy

Question 1

where does fertilization and cleavage occur?

Answer 1

occur in the fallopian tube/oviduct

Question 2

how many eggs and sperm need to be fertilized to create fraternal twins

Answer 2

2 eggs and 2 sperm fertilized

Question 3

how many eggs and sperm need to be fertilized to create identical twins

Answer 3

1 egg and 1 sperm

Question 4

how many zygotes are formed after fertilization of a one egg and one sperm

Answer 4

2 zygotes

Question 5

how are 2 zygotes created after fertilization of 1 egg and 1 sperm? C—

Answer 5

indeterminate cleavage/regulative cleavage

Question 6

what happens after 1st cleavage to both cells? what ability do they retain?

Answer 6

both cells that are separated retain the ability to develop into whole organisms

Question 7

what is fertilization synonymous with

Answer 7

syngamy

Question 8

what is syngamy

Answer 8

fusion of two gametes(sperm and egg) to form a zygote which marks the beginning of embryonic development

Question 9

for fertilization to occur, what does sperm have to penetrate

Answer 9

sperm penetrates plasma of 2 oocyte

Question 10

when sperm penetrates plasma of 2 oocyte what forms?

Answer 10

a zygote(spermatozoa)

Question 11

where does implantation of the embryo occur

Answer 11

occurs in the endometrium of the uterus (uterine lining)

Question 12

what is the cell called when implantation occurs in the endometrium of the uterus

Answer 12

blastocyst

Question 13

what block is formed after sperm has made contact with egg

Answer 13

block to polyspermy

Question 14

what are the blocks that prevent polyspermy

Answer 14

fast and slow block

Question 15

how does fast block work

Answer 15

involves enzymes from the sperm= acrosomal reaction—> cause changes in the cell voltage

Question 16

how does slow block work

Answer 16

cortical granules bind to membrane and create a physical barrier called vitelline layer to prevent sperm from entering

Question 17

what are the key stages of embryonic development? from first to last?

Answer 17

fertilization–> cleavage–> Morula–>blastula–> gastrula–>organogenesis

Question 18

what does cleavage do

Answer 18

mitotic divisions

Question 19

how does cleavage affect number of cells and growth

Answer 19

increase in cell number but no growth

Question 20

what cells result from cleavage

Answer 20

blastomeres

Question 21

what is formed at the end of cleavage

Answer 21

morula

Question 22

what is morula

Answer 22

solid ball of cells

Question 23

what is blastula

Answer 23

hollow sphere of cells with fluid filled cavity

Question 24

what is the fluid filled cavity in blastula called

Answer 24

blastocoel

Question 25

what is trophoblast

Answer 25

outer layer of blastula

Question 26

what is a precursor to placenta

Answer 26

outer layer of blastula

Question 27

what implants into uterus

Answer 27

blastula implants into the uterine lining to begin pregnancy

Question 28

what do cells do in gastrulation and what do they form

Answer 28

cells invaginate into gastrula and form 3 germ layered embryo

Question 29

what three germ layer are created

Answer 29

ectoderm, mesoderm, endoderm

Question 30

what germ layers are found in skin

Answer 30

ectoderm

Question 31

what germ layer is found in eyes

Answer 31

ectoderm

Question 32

what germ layer is found in muscles

Answer 32

mesoderm

Question 33

what germ layer is found in lungs, digestive tract, respiratory, urinary tract

Answer 33

endoderm

Question 34

what germ layer is found in hair, nails, teeth

Answer 34

ectoderm

Question 35

what germ layer is found in bones

Answer 35

mesoderm

Question 36

what germ layer is found in blood and lymphatic kidney

Answer 36

mesoderm

Question 37

what germ layer is found in nervous system

Answer 37

ectoderm

Question 38

what germ layer is found in epithelial lining

Answer 38

ectoderm

Question 39

what is a blastopore

Answer 39

opening of archenteron

Question 40

what describes where an archenteron develops

Answer 40

primitive gut (develops into the digestive tract)

Question 41

when does blastopore become anus first

Answer 41

becomes anus 1st in deuterostomes

Question 42

when does blastopore become mouth first

Answer 42

becomes mouth 1st in protostomes

Question 43

what is cephalization

Answer 43

sensory structures and nerve cells mainly in head

Question 44

what type of symmetry occurs in cephalization

Answer 44

bilateral symmetry

Question 45

what is organogenesis? what does it do to cells

Answer 45

is the process where cells differentiate to form organs from the three germ layers(ectoderm, mesoderm, endoderm)

Question 46

what chordates are affected by organogenesis

Answer 46

notochord, neural tube/plate, somites

Question 47

what does notochord become once it goes through organogenesis? what specific germ layer does it differentiate from?

Answer 47

becomes vertebras from mesoderm

Question 48

what does neural tube/plate become once it goes through organogenesis? what specific germ layer does it differentiate from?

Answer 48

the neural plate(from ectoderm) folds to become the brain/spinal cord which develops into central nervous system

Question 49

what does somites become once it goes through organogenesis? what specific germ layer does it differentiate from?

Answer 49

becomes backbone, skull, ribs, and skeletal muscle (meso)

Question 50

what are somites? and where do they form?

Answer 50

segmented blocks of tissue that form on the sides of the notochord

Question 51

where is gray crescent located and what does it form? what type of symmetry does it help establish?

Answer 51

opposite the entry of sperm and it forms the body axis which helps establish bilateral symmetry

Question 52

when does neural plate form

Answer 52

forms when ectodermal cells elongate and then it folds into the neural tube

Question 53

what type of eggs have polarity

Answer 53

animal eggs have polarity

Question 54

what type of fertilization do reptiles, birds, and monotremes do?

Answer 54

internal fertilization

Question 55

where do embryo develop in reptiles, birds, and monotremes

Answer 55

develop externally within an egg after fertilization

Question 56

what membranes support the embryo in reptiles, birds, and monotremes

Answer 56

chorion, allantois, yolk sac, amnion

Question 57

what type of fertilization do fish and amphibians do?(E or I)

Answer 57

external fertilization

Question 58

where does embryo develop in fish and amphibians

Answer 58

external development

Question 59

what membranes do fish and amphibians lack

Answer 59

lack amnion and allantois

Question 60

what is chorion

Answer 60

outer membrane implants into the endometrium

Question 61

what is function of charion in reptiles and birds

Answer 61

moist membrane that connects to shell and permits gas exchange

Question 62

what is allantois involved in

Answer 62

in respiration and excretion

Question 63

what does allantois store?

Answer 63

stores nitrogenous waste in the form of an acid (O2, CO2, H2, salts )

Question 64

what do blood vessels from the allantois become?

Answer 64

become the umbilical cord

Question 65

what is function of yolk sac

Answer 65

source of food(provides nutrients)

Question 66

what is function of amniotic fluid

Answer 66

cushion, shock absorber and protection

Question 67

what is amniotic fluid vital during

Answer 67

vital during contractions

Question 68

what is amniotic fluid enclosed by

Answer 68

enclosed by amnion

Question 69

what are the two fertility methods

Answer 69

in vitro fertilization and micro injection technique

Question 70

how does in vitro fertilization occur

Answer 70

fertilization between egg and sperm in a glass dish

Question 71

how does micro injection technique occur

Answer 71

sperm is directly injected into the egg

Question 72

why is micro injection technique done? what is it a treatment for?

Answer 72

done when sperm count is low and abnormal swimming sperm. treatment for make infertility