Download Chemistry Problem Solving Drill

Human Anatomy - Problem Drill 24: Developmental Anatomy
Question No. 1 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems
on paper as needed, (3) Pick the answer, and (4) Review the core concept tutorial as needed.
1. Which of the following statements about fertilization is not correct?
Question #01
(A) Prenatal development takes place after fertilization.
(B) Fertilization is the point of fusion of two somatic cells.
(C) Fertilization typically involves 1 sperm and 1 ovum.
(D) Ovum activation takes place after fertilization.
(E) None of the answers is correct.
A. Incorrect!
Prenatal development takes place after fertilization.
B. Correct!
Fertilization is the point of fusion of two gametes.
C. Incorrect!
Fertilization typically involves 1 sperm and 1 ovum.
Feedback
D. Incorrect!
Ovum activation takes place after fertilization. The acrosome reaction takes place in
which the spermatozoa and ovum plasma membranes fuse. This leads to an
“activation” of the ovum, which causes its plasma membrane to block fusion with
other spermatozoa.
E. Incorrect!
There is one correct answer above.
The goal of each spermatozoa is to find an ovum and begin the process of
fertilization. Fertilization, or conception, is the point of fusion between two
gametes. Inside the fallopian tube, the spermatozoa and ovum meet. Next, the
spermatozoa bind to the extracellular matrix surrounding the ovum, known as the
zona pellucida. Next, the acrosome reaction takes place in which the spermatozoa
and ovum plasma membranes fuse. This leads to an “activation” of the ovum,
which causes its plasma membrane to block fusion with another spermatozoa. This
ensures typically only 1 spermatozoa fertilization per ovum.
(B)Fertilization is the point of fusion of two somatic cells.
Solution
RapidLearningCenter.com
 Rapid Learning Inc. All Rights Reserved
Question No. 2 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems
on paper as needed, (3) Pick the answer, and (4) Review the core concept tutorial as needed.
2. The corpus luteum plays a critical role in the female reproductive tract. Which of
the following statements about the corpus luteum is not correct?
Question #02
(A) The corpus luteum is formed during the luteal phase of the menstrual cycle.
(B) The corpus luteum secretes estrogen and progesterone.
(C) The corpus luteum secretes hormones independent of implantation,
throughout the pregnancy.
(D) If a fertilized egg implants in the uterus, the hormone production of the
corpus luteum continues.
(E) Follicular development involves the corpus luteum.
A. Incorrect!
The corpus luteum is formed during the luteal phase of the menstrual cycle.
B. Incorrect!
The corpus luteum secretes estrogen and progesterone, before and after
implantation.
C. Correct!
The corpus luteum secretes estrogen and progesterone and, if a fertilized egg
implants in the uterus, this hormone production continues.
Feedback
D. Incorrect!
The corpus luteum secretes estrogen and progesterone and, if a fertilized egg
implants in the uterus, this hormone production continues.
E. Incorrect!
Follicular development involves the corpus luteum.
The second stage of follicular development takes place during the menstrual cycle.
Granulosa cells grow and develop and eventually form a layer surrounding the
oocyte in the pre-ovulatory stage. In the third and final stage of follicular
development, a single graafian follicle is surrounded with antral fluid.
Approximately in the middle of the menstrual cycle, the pressure inside the follicle
increases and, with proteolytic digestion of the outside wall, the ovum is released
into the peritoneal cavity. The corpus luteum is formed during the luteal phase of
the menstrual cycle. This occurs after ovulation. The corpus luteum secretes
estrogen and progesterone and, if a fertilized egg implants in the uterus, this
hormone production continues.
Solution
(C)The corpus luteum secretes hormones independent of implantation,
throughout the pregnancy.
RapidLearningCenter.com
 Rapid Learning Inc. All Rights Reserved
Question No. 3 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems
on paper as needed, (3) Pick the answer, and (4) Review the core concept tutorial as needed.
3. Which component of the blastocyst is labelled in the image below?
Question #03
(A) Trophoblast.
(B) Inner cell mass.
(C) Blastocele.
(D) Morula.
(E) None of the answers is correct.
A. Incorrect!
The trophoblast is the superficial layer that surrounds the blastocyst.
B. Correct!
The inner cell mass is where the cells forms the body of the embryo. These stem
cells are the beginnings of all the cells of the body and are protected from the
outside environment by the surrounding trophoblast.
C. Incorrect!
The interior (blastocele) of the blastocyst is a fluid-filled cavity; that later is
involved in the processes of gastrulation.
Feedback
D. Incorrect!
The morula is converted into a hollow ball of cells, known as a blastocyst. The
interior of the blastocyst is known as the blastocele, and approximately 70-100
cells make up the blastocyst.
E. Incorrect!
Answer B is correct.
Solution
The blastocyst is made up of the blastocele and the inner cell mass; these are
surrounded by the trophoblast. The interior (blastocele) of the blastocyst is a fluidfilled cavity; that later is involved in the processes of gastrulation. The inner cell
mass is where the cells forms the body of the embryo. These stem cells are the
beginnings of all the cells of the body and are protected from the outside
environment by the surrounding trophoblast. The trophoblast is a superficial layer
of cells that surrounds the blastocyst and is involved in the formation of the
placenta and implantation; these are the only cells of the pre-embryo in contact
with the uterus.
(B)Inner cell mass.
RapidLearningCenter.com
 Rapid Learning Inc. All Rights Reserved
Question No. 4 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems
on paper as needed, (3) Pick the answer, and (4) Review the core concept tutorial as needed.
4. A 26-year-old female is diagnosed with a disorder in which her body produces
blastocsyts with a defective trophoblast layer. Based on this information, which of
the following is correct?
Question #04
(A) The defective portion of the blastocyst secretes estrogen.
(B) Each blastocyst formed in this woman’s reproductive tract would be expected
to implant in the uterine wall normally.
(C) The inner-cell mass which facilitates implantation in the uterine wall would be
expected to function normally.
(D) Normally, on day 7 post-fertilization, the trophoblast cells that come into
contact with the uterine wall multiply to a few cell layers in thickness. This
process would be expected to be defective in this patient.
(E) None of the answers is correct.
A. Incorrect!
The trophoblast eventually becomes the placenta.
B. Incorrect!
The implantation of the blastocyst would be expected to be abnormal in this patient
because of the defective trophoblast layer.
C. Incorrect!
The inner cell mass is where the cells forms the body of the embryo.
Feedback
D. Correct!
On day 7 post-fertilization, the trophoblast cells that come into contact with the
uterine wall multiply to a few cell layers in thickness.
E. Incorrect!
Answer D is correct.
Solution
The blastocyst is made up of the blastocele and the inner cell mass; these are
surrounded by the trophoblast. The interior (blastocele) of the blastocyst is a fluidfilled cavity; that later is involved in the processes of gastrulation. The inner cell
mass is where the cells forms the body of the embryo. These stem cells are the
beginnings of all the cells of the body and are protected from the outside
environment by the surrounding trophoblast. The trophoblast is a superficial layer of
cells that surrounds the blastocyst and is involved in the formation of the placenta
and implantation; these are the only cells of the pre-embryo in contact with the
uterus.
(D)Normally, on day 7 post-fertilization, the trophoblast cells that come
into contact with the uterine wall multiply to a few cell layers in
thickness. This process would be expected to be defective in this patient.
RapidLearningCenter.com
 Rapid Learning Inc. All Rights Reserved
Question No. 5 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems
on paper as needed, (3) Pick the answer, and (4) Review the core concept tutorial as needed.
5. Which component of the blastodisc is labelled in the image below?
Question #05
(A) Epiblast.
(B) Hypoblast.
(C) Mesoderm.
(D) Morula cell lawyer.
(E) Amnion.
A. Incorrect!
The epiblast is the upper portion of the blastodisc; it is the layer of inner cell mass
that faces the amniotic cavity prior to gastrulation.
B. Correct!
Hypoblast.
C. Incorrect!
The mesoderm develops from the cells in the interior of the blastodisc.
Feedback
D. Incorrect!
The Morula is converted into a hollow ball of cells, known as a blastocyst.
E. Incorrect!
On day 10, the epiblast cells migrate around the amniotic cavity and this contributes
to the formation of the amnion.
Solution
The blastodisc begins to form at day 9 and is made up of two epithelial layers:
epiblast and hypoblast. The epiblast is the layer of inner cell mass that faces the
amniotic cavity prior to gastrulation. The hypoblast is the portion of the inner cell
mass that faces the blastocele. On day 10, the epiblast cells migrate around the
amniotic cavity and this contributes to the formation of the amnion. Also, the
hypoblast cells create a sac that hangs below the blastodisc, which eventually
becomes the yolk sac.
(B)Hypoblast.
RapidLearningCenter.com
 Rapid Learning Inc. All Rights Reserved
Question No. 6 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems
on paper as needed, (3) Pick the answer, and (4) Review the core concept tutorial as needed.
6. The primary germ cell layers that develop from the blastodisc develop early in
embryonic development. Which of the following statements about the primary germ
cell layers is correct?
Question #06
(A) The three germ cell layers are the ectoderm, mesoderm and epiderm.
(B) The migration of epiblast cells between the two layers of the blastodisc gives
rise to the germ cell layer, known as the ectoderm.
(C) The ectoderm gives rise to the dura mater, bone, muscle.
(D) The ectoderm forms from the hypoblast.
(E) The endoderm gives rise to connective tissue, dura mater, bone, muscle,
cardiovascular components, and blood.
A. Incorrect!
The three germ cell layers are the ectoderm, mesoderm and endoderm.
B. Correct!
The migration of epiblast cells between the two layers of the blastodisc gives rise to
the germ cell layer, known as the ectoderm.
Feedback
C. Incorrect!
The ectoderm gives rise to the following categories of tissue: Surface ectoderm –
gives rise to adenohypophysis; formation of epidermis, epithelial linings of skin, ear,
nose and eye.
D. Incorrect!
The ectoderm forms from the epiblast.
E. Incorrect!
The endoderm gives rise to the formation of gut epithelium and its derivatives, such
as thyroid follicular cells, parathyroid, thymus, lungs, liver and pancreas.
Solution
On day 12, the migration of epiblast cells between the two layers of the blastodisc
gives rise to the germ cell layer, known as the ectoderm. The other two primary
germ cell layers are the endoderm, which forms from the hypoblast, and the
ectoderm, which forms from the epiblast. Gastrulation is a developmental stage for
embryos; it generates three layers of cells, which can further differentiate into
organs. The ectoderm gives rise to the following categories of tissue: Surface
ectoderm – gives rise to adenohypophysis; formation of epidermis, epithelial linings
of skin, ear, nose and eye. The mesoderm gives rise to the formation of connective
tissue, dura mater, bone, muscle, cardiovascular components, blood, and urogenital
structures, including kidneys, spleen, and adrenal cortex. The endoderm gives rise
to the formation of gut epithelium and its derivatives, such as thyroid follicular cells,
parathyroid, thymus, lungs, liver and pancreas. The endoderm also forms the lining
of the digestive and respiratory systems, some structures of the ear, and other
internal structures.
(B)The migration of epiblast cells between the two layers of the
blastodisc gives rise to the germ cell layer, known as the ectoderm.
RapidLearningCenter.com
 Rapid Learning Inc. All Rights Reserved
Question No. 7 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems
on paper as needed, (3) Pick the answer, and (4) Review the core concept tutorial as needed.
7. Which extraembryonic membrane is labeled in the image below?
Question #07
(A) Yolk-sac.
(B) Chorion.
(C) Amnion.
(D) Allantois.
(E) Umbilical membrane.
A. Incorrect!
The yolk sac, which is formed from migrating hypoblast cells and eventually this
structure, becomes the site of early blood cell formation.
B. Incorrect!
The chorion is a combination of the mesoderm and trophoblast and, during
development; blood vessels travel through the chorion and deliver blood to the
developing embryo.
C. Incorrect!
The amnion is a combination of ectoderm and the mesoderm.
Feedback
D. Correct!
The allantois forms from outpocket of the endoderm. This eventually gives rise to
the urinary bladder.
E. Incorrect!
The allantois is labeled in the image and it forms from outpocket of the endoderm.
This eventually gives rise to the urinary bladder.
Solution
During embryogenesis, four different extraembryonic membranes develop: (1) yolk
sac, which is formed from migrating hypoblast cells and eventually this structure
becomes the site of early blood cell formation, (2) the amnion is a combination of
ectoderm and the mesoderm. As development proceeds, the amniotic fluid
surrounds and cushions the developing embryo, (3) the allantois forms from an
outpocket of the endoderm. This eventually gives rise to the urinary bladder, and (4)
the Chorion. The chorion is a combination of the mesoderm and trophoblast and,
during development; blood vessels travel through the chorion and deliver blood to
the developing embryo.
(D) Allantois.
RapidLearningCenter.com
 Rapid Learning Inc. All Rights Reserved
Question No. 8 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems
on paper as needed, (3) Pick the answer, and (4) Review the core concept tutorial as needed.
8. Which of the following statement is correct about the development of the skull
and vertebral column?
Question #08
(A) The skull develops from a series of cartilages that surround the brain and are
formed by the 5th week of development.
(B) By the 4th week of development the chondrocranium houses the brain and
the organs of sense.
(C) The mesenchymal blocks known as the somites contain a region known as
the sclerotome, which along their path form the bones of the skull.
(D) By the 4th week of development, the vertebral centra grow around the spinal
cord and form the structure for the completed vertebra.
(E) None of the answers are correct.
A. Correct!
The skull develops from a series of cartilages that surround the brain and are formed
by the 5th week of development.
B. Incorrect!
By the 8th week of development the combination of the cartilage and skull, known as
the chondrocranium houses the brain and the organs of sense.
C. Incorrect!
The mesenchymal blocks known as the somites contain a region known as the
sclerotome, which along their path form the vertebral column.
Feedback
D. Incorrect!
By the 8th week of development, the vertebral centra grow around the spinal cord
and form the structure for the completed vertebra.
E. Incorrect!
Answer A is correct.
The skull develops from a series of cartilages that surround the brain and are formed
by the 5th week of development. By the 8th week of development the combination of
the cartilage and skull, known as the chondrocranium hoses the brain and the
organs of sense. The developing spinal cord in the 4th week is located posterior to
the notochord. The mesenchymal blocks known as the somites contain a region
known as the sclerotome, which along their path form the vertebral column. By the
8th week of development, the vertebral centra grow around the spinal cord and form
the structure for the completed vertebra. At birth there are still many cartilaginous
regions in the vertebrae.
Solution
(A)The skull develops from a series of cartilages that surround the brain
and are formed by the 5th week of development.
RapidLearningCenter.com
 Rapid Learning Inc. All Rights Reserved
Question No. 9 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems
on paper as needed, (3) Pick the answer, and (4) Review the core concept tutorial as needed.
9. Which of the following statements about the development of the brain is not
correct?
Question #09
(A) By 4 weeks of development the Telencephalon, Diencephalon,
Mesencephalon, Metencephalon, and the Myelencephalon form.
(B) By 8 weeks of development, the meninges are developing and the blood
vessels begin to form the choroid plexus.
(C) The cerebral hemisphere has developed by the 5th week.
(D) As development progresses the choroid plexus will eventually be part of the
ventricular system of the brain where the cerebral spinal fluid (CSF) is
produced.
(E) None of the answers are correct.
A. Incorrect!
By 4 weeks of development the Telencephalon, Diencephalon, Mesencephalon,
Metencephalon, and the Myelencephalon form.
B. Incorrect!
By 8 weeks of development, the meninges are developing and the blood vessels
begin to form the choroid plexus.
C. Correct!
By 11 weeks of development, the telencephalon (cerebral hemisphere) has
developed.
Feedback
D. Incorrect!
As development progresses the choroid plexus will eventually be part of the
ventricular system of the brain where the cerebral spinal fluid (CSF) is produced.
E. Incorrect!
Answer C is correct.
Solution
Prior to the closure of the neural tube, the initial cephalic expansions occur, during
brain development. By 4 weeks of development (28 days), the distinct brain
vesicles, through subdividing, lead to the formation of the: Telencephalon,
Diencephalon, Mesencephalon, Metencephalon, and the Myelencephalon. By 8 weeks
of development, the meninges are developing and the blood vessels begin to form
the choroid plexus. The choroid plexus will eventually be part of the ventricular
system of the brain where the cerebral spinal fluid (CSF) is produced. By 11 weeks
of development, the telencephalon (cerebral hemisphere) has developed. Eventually,
as development progresses, the mesencephalon will be comprised of the tectum and
cerebral peduncles and be joined with the metencephalon, also known at this stage
as the pons.
(C)
The cerebral hemisphere has developed by the 5th week.
RapidLearningCenter.com
 Rapid Learning Inc. All Rights Reserved
Question No. 10 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems
on paper as needed, (3) Pick the answer, and (4) Review the core concept tutorial as needed.
10. The developmental of the male and female reproductive system, initially,
involves a common anatomical anatomy. Which of the following statements about
the development of the male and female reproductive system is correct?
Question #10
(A) The Wolffian duct progresses to form the fallopian tubes, uterus and a portion
of the vagina.
(B) The Mesonephric duct is another name for the Mullerian duct.
(C) Male development is dependent on the SRY gene of the Y chromosome.
(D) The developing testes secrete factor that inhibits the development of the
Wolffian duct.
(E) None of the answers are correct.
A. Incorrect!
The Wolffian duct progresses to form the Seminal vesicles, Epididymis, Ejaculatory
duct and Ductus deferens.
B. Incorrect!
The Mesonephric duct is another name for the Wolffian duct.
C. Correct!
Male development is dependent on the SRY gene of the Y chromosome, which is
responsible for testis-determining factor.
Feedback
D. Incorrect!
The developing testes secrete a paramesenteric or Mullerian duct inhibiting factor
and androgens, which promote development of the Mesonephric or Wolffian duct.
E. Incorrect!
Answer C is correct.
Solution
Female development is the default development with disappearance of the
mesonephric duct or Wolffian duct and development of the paramesenteric or
Mullerian duct, which progresses to form the fallopian tubes, uterus and a portion of
the vagina. Male development is dependent on the SRY gene of the Y chromosome,
which is responsible for testis-determining factor. The developing testes secrete a
paramesenteric or Mullerian duct inhibiting factor and androgens, which promote
development of the Mesonephric or Wolffian duct. The mesonephric duct
progresses to form the Seminal vesicles, Epididymis, Ejaculatory duct and Ductus
deferens – SEED.
(C)
Male development is dependent on the SRY gene of the Y
chromosome.
RapidLearningCenter.com
 Rapid Learning Inc. All Rights Reserved