Ch 29. Development
What is the fate of the cluster of cells in the blastocyst known as the inner cell mass?
The cells will develop into the embryo.
state of full development or completed growth
maturity
A hollow ball of cells created by cleavage is called a
blastocyst
The chorion develops from the _____
mesoderm and trophoblast
Three layers of gastrulation
ectoderm, mesoderm, endoderm
Study of embryonic development
embryology
Pregnancy events from week 3-8 are called
embryonic development
The infusion of two haploid (n) gametes each containing 23 chromosomes
fertilization
Transfer of genetically determined characteristics from generation to generation
inheritance, heredity
During cleavage the single large zygote is converted into a __________.
multicellular embryo consisting of smaller cells called blastomeres
Where does fertilization take place?
near the junction between the ampulla and isthmus of the uterine tube
Provides cellular organelles, nourishment, and genetic programming
oocyte
Begins at birth and continues to maturity
postnatal development
The processes that occur in the first 2 weeks after fertilization, producing an embryo
pre-embryonic development
Modification of anatomical structures and physiological characteristics that occur before birth is referred to as
prenatal development
When rapid fetal growth and deposition of adipose tissue takes place
third trimester
The extra-embryonic membranes that develop from the endoderm and the mesoderm are the ______.
yolk sac and amnion
thick, glycoprotein-rich membrane secreted by oocyte, encapsulating it
zona pellucida
46 chromosomes
zygote
The sudden increase in the calcium ion level has important effects including
-exocytosis of vesicles adjacent to the oocyte membranes -completions of meiosis two -activation of enzymes that cause a rapid increase in the ovums metabolic rate
When does fertilization occur?
12-24 hours after ovulation
Out of the 200-500 million sperm cells that are released during an ejaculation, only ____ complete the short journey up the Fallopian tubes to where an egg is waiting to be fertilized.
about 10,000
Frees the enzymes contained in the acrosome of each sperm
acrosome reaction
senescence
aging
What is the extra embryonic membrane that gives rise to the urinary bladder
allantois
The combining of male and female chromosomes is called
amphimixis
The fusion of male and female pronuclei is termed ____.
amphimixis
Cleavage ends when
blastocyst contacts uterine wall
Prevents fertilization by more than one sperm
block to polyspermy
Glycoprotein layer of the sperm membrane is removed
capacitation
Which of the following forms the placenta
chorion
A sequence of cell divisions that begin after fertilization is called __________.
cleavage
A sequence of cell divisions that begins immediately after fertilization is called ___________.
cleavage
What is the correct sequence of events going from the zygotes to the fetus
cleavage, implantation, placentation, embryogenesis
Follicle cells that line the zona pellucida
corona radiata
Releases enzymes called zonal inhibiting proteins (ZIPs)
cortical reaction
The exocytosis of vesicles adjacent to the oocyte membrane is called the
cortical reaction
Begins at week 9 and continues until birth
fetal development
How many sperm reach the isthmus
fewer than 100
Period of pre-embryonic, embryonic, and early fetal development
first trimester
What is the "moment of conception"
fusion of the male and female pronuclei
What triggers the activation of the secondary oocyte
fusion of the sperm and secondary oocyte membranes
Study of mechanisms responsible for inheritance is called
genetics
The time spent in prenatal development is known as
gestation
Breaks down the bonds between adjacent follicle cells
hyaluronidase
Which of the following enzymes are released from the acrosome of sperm?
hyaluronidase and acrosin
Begins when the blastocyst attaches to the endometrium of the uterus
implantation
When development of fetal organs and organ systems takes place
second trimester
Delivers the paternal (fathers) chromosomes to the site of fertilization
sperm
The umbilical cord or umbilical stalk, contains _______
the allantois, blood vessels, and yolk stalk
