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.
By the beginning of the twelfth week, the placenta has two distinct parts:
a) the fetal portion formed by the chorionic villi of the chorion
b) the maternal portion formed by the decidua basalis of the endometrium
c) the maternal portion formed by the the lacunar networks and maternal sinusoids
d) a and b
e) none of the above
d) a and b
________ involves conversion from a flat two-dimensional trilaminar embryonic disc into a three dimensional cylinder.
a. Embryonic folding
b. Gastrulation
c. Placentation
d. Neurulation
a. Embryonic folding
The lateral folds incorporate the dorsal part of the yolk sac into the embryo as the primitive gut.
a. True
b. False
a. True
Pharyngeal arches, clefts, and pouches give rise to the structures of the head and neck.
a. True
b. False
a. True
Limb buds are out growths of ectooderm covered by mesoderm.
a. True
b. False
b. False
By the end of the second half of the embryonic period:
a. all regions of the limbs are developed and digits are distinct and no longer webbed
b. all regions of the trunk are developed
c. all regions of the face are developed
d. the limbs are mostly developed but the digits are still webbed
a. all regions of the limbs are developed and digits are distinct and no longer webbed
________ is the time mostly concerned with growth and differentiation of tissues and organs that developed during the embryonic period.
a. Fetal period
b. Third trimester
c. Prenatal
d. Fourth trimester
a. Fetal period
In weeks 9 – 12, the head is about 1/16 of the length of the body but becomes more proportionate as pregnancy progresses.
a. True
b. False
b. False
Symptoms of fetal alcohol syndrome include:
a. slow growth before and after birth
b. thin upper lip and sunken nasal bridge
c. defective heart and other organs
d. central nervous system damage
e. all of these
e. all of these
Which of the following statements is correct?
a. Fetal ultrasonography may be used to determine a more accurate fetal age when conception date is unclear.
b. Amniocentesis may be used to detect genetic disorders such as Down’s syndrome.
c. Chorionic villi sampling can be used to detect genetic disorders.
d. Noninvasive test such as AFP (maternal alpha-fetoprotein) are considered less dangerous that invasive tests that may involve sampling fetal tissue
e. All of these are correct.
e. All of these are correct.
Which of the following statements is INCORRECT?
a. Progesterone and estrogens maintain the lining of the uterus during pregnancy.
b. Human chorionic gonadotropin stimulates the corpus luteum to secrete estrogens and progesterone.
c. Relaxin increases flexibility of the pubic symphysis and ligaments of sacroiliac joints and dilates the cervix during labor.
d. Human chorionic somatomammotropin helps to prepare the mammary glands for lactation and regulates metabolism of mother and fetus.
e. Corticotrophin releasing hormone is thought to be involved in timing of birth and decreases greatly as birth approaches.
e. Corticotrophin releasing hormone is thought to be involved in timing of birth and decreases greatly as birth approaches.
What structural and functional changes occur in the mother during pregnancy?
a. the uterus grows to occupy most of the pelvic cavity
b. weight gain
c. stroke volume and cardiac output rise
d. expiratory reserve volume may be reduced
e. all of these changes occur
e. all of these changes occur
Which changes in pregnancy have an effect on the ability to exercise?
a. fatigue
b. morning sickness
c. weight gain and posture changes increase energy needed
d. loss of joint stability
e. all of these
e. all of these
What hormonal change(s) induce labor?
a. estrogens rise sharply
b. high estrogen levels cause an increase in the number of oxytocin receptors in uterine muscle fibers
c. oxytocin stimulates uterine contractions
d. relaxin increases the flexibility of the pubic symphysis and helps to dilate the cervix
e. all of these
e. all of these
Which of the following statements is/are INCORRECT?
a. In the stage of dilation, uterine contractions are regular, the amnionic sac ruptures and the cervix dilates completely.
b. The stage of expulsion is the time between complete dilation of the cervix and the first breath of the infant.
c. The placental stage is the time after delivery until the placenta is expelled.
d. Choices a and b are incorrect.
b. The stage of expulsion is the time between complete dilation of the cervix and the first breath of the infant.
Respiratory and cardiovascular adjustments are important at birth because the infant must switch from being dependent on the mother to being self supporting.
a. True
b. False
a. True
Which of the following statements is INCORRECT?
a. Prolactin is the principle hormone in promoting milk production.
b. Oxytocin is responsible for the milk ejection reflex.
c. Prolactin is inhibited during pregnancy by luteinizing hormone.
c. Prolactin is inhibited during pregnancy by luteinizing hormone.
Benefits of breast feeding over bottle feeding include:
a. human milk offers ideal nutrition
b. human milk has cells that fight infection.
c. human milk has beneficial molecules such as antibodies and proteins that bind to nutrients that bacteria need to grow.
d. breast feeding provides a slight reduction in risk of diseases such as lymphoma, heart disease, allergies and meningitis.
e. all of these are benefits.
e. all of these are benefits
Which of the following statements is INCORRECT?
a. The genetic makeup of an individual is referred to as its genotype.
b. Phenotype refers to how the genetic makeup is expressed in the body.
c. An allele that dominates or masks the presence of another allele is referred to as dominant.
d. A person with the same alleles on homologous chromosomes is said to be homozygous
e. A person with different alleles on homologous chromosomes is said to be experiencing nondisjunction.
e. A person with different alleles on homologous chromosomes is said to be experiencing nondisjunction.
In ________, the same gene expresses a different phenotype in males and females.
a. nondisjunction
b. genomic imprinting
c. translocation
d. aneuploidy
b. genomic imprinting
In incomplete dominance, neither allele pair is dominant so the phenotype is intermediate between the two. An example of this is ________.
a. sickle cell disease
b. ABO blood group inheritance
c. polygenic inheritance
d. phenylketonuria
a. sickle cell disease
If genes have more than two alternative forms, such as the ABO blood group genes, this is referred to as:
a. mutational inheritance
b. incomplete dominance
c. multiple-allele inheritance
d. phenylketonuria
c. multiple-allele inheritance
When inherited traits such as hair color are controlled by many genes and environmental factors, the situation is referred to as ________.
a. multiple-allele inheritance
b. incomplete dominance
c. complex inheritance
d. polyploidy
c. complex inheritance
________ balances the difference in the number of X chromosomes in males and females.
a. X-Chromosome inactivation
b. Polygenic inheritance
c. Polyploidy
d. Complex inheritance
a. X-Chromosome inactivation
