CH 29 Development & Inheritance Flashcards
Choose the statements that apply to the second trimester. Select all that apply.
a. characterized by nearly complete development of organ systems
b. weight of the fetus doubles
c. most critical stage of development
d. fetus assumes distinctively human features by the end of the phase
e. the developing organism is most venerable to the effects of drugs and radiation
a. characterized by nearly complete development of organ systems
d. fetus assumes distinctively human features by the end of the phase
The fast block to polyspermy involves depolarization of the oocyte membrane while the slow block involves inactivation of ZP3.
a. True
b. False
a. True
The morula:
a. is a solid ball of cells
b. is formed by cleavage of cells in the zygote
c. is surrounded by the zona pellucida
d. all of these
d. all of these
Which of the following statements is INCORRECT?
a. The embryoblast is located on the outside of the blastocyst.
b. The trophoblast will develop into the outer chorionic sac and the fetal portion of the placenta.
c. The embryoblast will develop into the embryo.
a. The embryoblast is located on the outside of the blastocyst.
Which of the following statements is INCORRECT?
a. Implantation occurs about six days after fertilization.
b. Implantation occurs in either the posterior fundus or body of the uterus.
c. When implantation occurs, the inner cells mass orients toward the uterine cavity.
d. Seven days after fertilization, the blastocyst becomes firmly attached and the endometrium becomes more vascularized.
c. When implantation occurs, the inner cells mass orients toward the uterine cavity.
NOTE:
Orients towards the endometrium
The trophoblast:
a. develops into a syncytiotrophoblast and a cytotrophoblast.
b. becomes part of the chorion.
c. secretes enzymes that aid in implantation.
d. secretes human chorionic gonadotropin which helps to maintain the corpus luteum.
e. all of these
e. all of these
Cells of the embryoblast differentiate into 2 layers, the hypoblast and the epiblast. Together these layers form:
a. bilaminar embryonic disc
b. trophoblast
c. laminar embryonic disc
d. primitive streak
a. bilaminar embryonic disc
Which of the following statements is correct?
a. The amnion forms the roof of the amnionic cavity and eventually surrounds the entire embryo.
b. The exocoelomic membrane and the hypoblast form the wall of the yolk sac.
c. The extraembryonic mesoderm along with the cytotrophoblast and syncytiotrophoblast form the chorion.
d. The chorion becomes part of the placenta and protects the embryo and fetus from the mother’s immune response.
e. All of these statements are correct.
e. All of these statements are correct.
What supplies nutrients to the embryo?
a. endocardial tubes
b. organogenesis
c. yolk sac
d. allantosis
c. yolk sac
When does gastrulation occur?
a. third week of development
b. fourth week of development
c. fifth week of development
d. fifth day of development
a. third week of development
_______ is the process by which one tissue stimulates the development of an adjacent unspecialized tissue.
a. Conduction
b. Induction
c. Gastrulation
d. Transmutation
e. Angiogenesis
b. Induction
In ________, the bilayered embryonic disc transforms into a trilaminar embryonic disc that forms the three primary germ layers from which the organs and tissues of the body develop.
a. organogenesis
b. gastrulation
c. invagination
d. induction
b. gastrulation
Which of the following develop from mesodermal cells by the process of neurulation? Select all that apply.
a. neural plate
b. neural folds
c. neural tube
d. neural cap
a. neural plate
b. neural folds
c. neural tube
Somites form skeletal muscle, connective tissue, vertebrae, and ribs.
a. True
b. False
a. True
Which of the following statements is correct regarding angiogenesis?
a. Angiogenesis begins in the extraembryonic mesoderm in the yolk sac, connecting stalk and chorion.
b. In angiogenesis mesodermal cells develop into hemangioblasts.
c. Angioblasts develop into blood islands in which spaces form blood vessel lumens.
d. Angioblasts form the endothelium and tunics of blood vessels.
e. All of these are correct.
e. All of these are correct.