Chapter 4 - Vertebrate Embryology

Question 1

Embryology

Answer 1

study of development of a unicellular zygote into complete multicellular organism

Question 2

in course of nine months, a unicellular human zygote undergoes ___ in preparation for life outside uterus

(human embryology)

Answer 2

cell division

cellular differentiation

morphogenesis

Question 3

mammalian development studied in

Answer 3

sea urchins

frogs

Question 4

Early Developmental Stages

(5)

Answer 4

Fertilization

Cleavage

Gastrulation

Development

Birth and Maturation

Question 5

1. Fertilization

(developmental stages)

can begin within ___

Answer 5

12-24 hours following ovulation

Question 6

fertilization occurs in the

Answer 6

lateral, widest portion of oviduct

Question 7

fertilization occurs when

Answer 7

sperm traveling from vagina encounter an egg

Question 8

If more than one egg is fertilized ____

Answer 8

fraternal twins may be conceived

Question 9

1. Cleavage

Answer 9

series of rapid mitotic divisions

characterize early embryonic development

Question 10

cleavage divisions lead to increase in ___

Answer 10

cell number w/o corresponding growth in protoplasm

total volume of cytoplasm constant

Question 11

cleavage results in

Answer 11

progressively smaller cells

Question 12

progressively smaller cells resulting from cleavage cause increase in

Answer 12

nuclear: cytoplasm ratio
surface: volume ratio of each cell

Question 13

cleavage increase of surface to volume ratio improves

Answer 13

gas and nutrient exchange

Question 14

indeterminate cleavage

Answer 14

cells maintain ability to develop into complete organism

if cells from first division separate, each cell can develop into own organism

Question 15

identical twins are result of

Answer 15

indeterminate cleavage

Question 16

determinate cleavage

Answer 16

cells whose future differentiation pathways determined early in dev

cells must be together for survival - cannot develop into own organism

Question 17

differentiation

Answer 17

specialization of cells that occurs during dev

Question 18

first complete cleavage of zygote occurs

Answer 18

~32 hours after fertilization

Question 19

second cleavage occurs after

Answer 19

60 hours

Question 20

third cleavage @

Answer 20

72 hours

Question 21

significance of third cleavage

Answer 21

8-celled embryo reaches uterus

Question 22

morula

Answer 22

solid ball of embryonic cells

(as cell dev continues)

Question 23

blastulation

Answer 23

transition of morula –> blastula

Question 24

blastulation begins when

Answer 24

morula develops fluid-filled cavity - blastocoel

Question 25

blastocoel

Answer 25

fluid filled cavity formed in morula during blastulation

Question 26

blastocyst

Answer 26

mammalian form of blastula

Question 27

blastula time structure

Answer 27

formed on the 4th day of blastulation perimeter: blastoderm interior: blastocoel

Question 28

gastrulation begins when

Answer 28

blastula implanted in uterus

Question 29

gastrulation

Answer 29

cell migrations transform single cell layer of blastoderms in blastula into three-layered structure: gastrula

Question 30

gastrula structure and function

Answer 30

three primary germ layers differential development of: tissues organs systems of body

Question 31

three primary germ layers of gastrula

Answer 31

ectoderm endoderm mesoderm

Question 32

ectoderm (1 of 3 primary germ layers of gastrula)

Answer 32

integument lens of eye retina nervous system

Question 33

integument

Answer 33

epidermis hair nails epithelium of nose, mouth, anal canal

Question 34

endoderm

Answer 34

epithelial linings of digestive and respiratory tracts parts of liver, pancreas, thyroid, bladder lining

Question 35

mesoderm

Answer 35

musculoskeletal circulatory excretory gonads connective tissue portions of digestive and respiratory

Question 36

Development 3 types

Answer 36

external non-placental internal placental internal

Question 37

external development

Answer 37

early dev of may occur outside mother's body e.g. land, water

Question 38

external development fish and amphibians

Answer 38

lay eggs fertilized externally in water embryo develops within egg, feeding on nutrients stored in yolk

Question 39

external development reptiles, birds, some mammals (duck-billed platypus)

Answer 39

develops externally on land fertilization internal, then egg layed eggs protect embryo

Question 40

eggs embryonic membranes

Answer 40

chorion allantois amnion yolk sac

Question 41

chorion

Answer 41

lines inside of shell moist membrane permits gas exchange

Question 42

allantois

Answer 42

sac-like structure respiration, excretion blood vessels transport: O2, CO2, H2O, salt, nitrogenous waste

Question 43

amnion

Answer 43

encloses amniotic fluid

Question 44

amniotic fluid (amnion)

Answer 44

aqueous env. protects developing embryo from shock

Question 45

yolk sac

Answer 45

encloses yolk blood vessels transfer food to dev. embryo

Question 46

non placental internal development

Answer 46

early dev within body protects young marsupials, some tropical fish exchange of food and oxygen bw young & mother limited may be born very young

Question 47

placental internal development two main components

Answer 47

placenta umbilical cord

Question 48

placental internal develompent specialized circulatory system

Answer 48

mother ---\> fetus supplies oxygen removes CO2, metabolic waste

Question 49

placenta and umbilical cord develop within

Answer 49

first few weeks following fertilization

Question 50

placenta and umbilical cord outgrowths of 4 extraembryonic membranes

Answer 50

amnion chorion allantois yolk ac

Question 51

amnion | (pid)

Answer 51

thin, tough membrane contain watery fluid - amniotic fluid

Question 52

amniotic fluid (pid)

Answer 52

shock absorber of external and localized pressure from uterine contractions during labor

Question 53

chrion (pid)

Answer 53

membrane surrounds amnion leads to placenta formation

Question 54

allantois (pid)

Answer 54

third membrane develops as outpocketing of gut blood vessels of allantoic wall enlarge ---\> umbilical cord

Question 55

umbilical vessels (pid)

Answer 55

connect fetus to placenta

Question 56

yolk sac (pid)

Answer 56

early dev of blood vessels ---\> umbilical vessels

Question 57

Birth and Maturation

Answer 57

labor childbirth differentiation of cells until adulthood

Question 58

labor

Answer 58

series of strong uterine contractions 3 distinct stages

Question 59

1 stage labor

Answer 59

cervix thins out, dilates amniotic sac ruptures, releasing fluids mild contractions

Question 60

2 stage labor

Answer 60

rapid contractions birth of baby cutting umbilical cord

Question 61

3 stage labor

Answer 61

uterus contracts expells placenta, umbilical cord

Question 62

maturation embryo --\> adult

Answer 62

cell division growth differentiation

Question 63

maturation forms

Answer 63

suspended in temporary state e.g. arthropods - pupal stage uninterrupted e.g. mammals

Question 64

differentiation of cells complete when

Answer 64

all organs reach adult form