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NU 545 Unit 7 Questions and Answers
Describe the specific chromosomal abnormality responsible for
Down Syndrome
Ans: The most well known aneuploidy (those that do not contain a
multiple of 23 chromosomes) in an autosome is trisomy of the 21st
chromosome. J. Langdon Down 1st described the the disease in 1866.
Down syndrome is seen in 1 in 800 births. IQ's between 25 and 70. Facial
features: low nasal bridge, epicentral folds, protruding tongue, and flat
low set ears. Congenital heart defects in 1/3 to 1/2 of live born children.
Decreased ability to fight respiratory conditions and an increased
susceptibility to leukemia. By age 40 symptoms resembling Alzheimer
develop. 97% of Down Syndrome's cases are caused by nondisjunction
during the formation of one of the parent's gametes or during early
embryonic development. 3% from translocations. Risk increases with
maternal age.
Causes of mental retardation.
Ans: Chromosomal abnormalities.
What gene abnormality causes cystic fibrosis?
Ans: Like autosomal dominant diseases, those caused by autosomal
recessive alleles are rare in populations, although the number of carriers
for recessive diseases can be high. The most common lethal recessive
disease in white children, cystic fibrosis, occurs in about 1 in 2500
births. Approximately 1 in 25 whites carries one copy of an allele that
can cause cystic fibrosis (see Chapter 36). Because an individual must be
homozygous for a recessive allele to express thedisease, the carriers are
phenotypically normal. Because most recessive alleles are maintained
innormal carriers, they are able to survive in the population from one
generation to the next. As with many autosomal dominant diseases,
many autosomal recessive diseases are characterized by delayed age of
onset, incomplete penetrance, and variable expressivity.
How is a recessive gene inherited?
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, 2 | Page
Ans: Autosomal recessive diseases occur when both parents are carriers
of the same disease and their child inherits an altered gene from each of
them. Children of carrier parents have:A 25% chance of inheriting two
altered genes and developing the disease.
Inheritance of Hemophilia A?
Ans: Hemophilia A and hemophilia B are inherited in an X-linked
recessive pattern. The genes associated with these conditions are located
on the X chromosome, which is one of the two sex chromosomes. In
males (who have only one X chromosome), one altered copy of the gene
in each cell is sufficient to cause the condition. In females (who have two
X chromosomes), a mutation would have to occur in both copies of the
gene to cause the disorder. Because it is unlikely that females will have
two altered copies of this gene, it is very rare for females to have
hemophilia. A characteristic of X-linked inheritance is that fathers cannot
pass X-linked traits to their sons.
Inheritance of Hemophilia A?
Ans: In X-linked recessive inheritance, a female with one altered copy of
the gene in each cell is called a carrier. Carrier females have about half
the usual amount of coagulation factor VIII or coagulation factor IX,
which is generally enough for normal blood clotting. However, about 10
percent of carrier females have less than half the normal amount of one
of these coagulation factors; these individuals are at risk for abnormal
bleeding, particularly after an injury, surgery, or tooth extraction.
Risk factors for DM II; why is obesity an important risk factor for
DM II?
Ans: An important risk factor is TCF7L2 which encodes a transcription
factor involved in the secretion of insulin. Another association has been
found between a common allele of the gene that incomes peroxisome
proliferator-activated receptor gamma (PPAR-y), a nuclear receptor that is
involved in adipocyte differentiation and glucose metabolism. This
receptor is the target of thiazolidinediones (TZD's) a class of drugs
commonly used to increase insulin sensitivity in those with type 2
diabetes. The 2 most important risk factors for DM II are positive family
history and obesity; the latter increases insulin resistance.
Definition of carcinoma
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, 3 | Page
Ans: Cancer arising from in epithelial cells
How do cancer cells gain access to the circulation?
Ans: cells gain access to circulation through new tumor-associated blood
vessels or angiongesis
Mobile tumor cells are able to enter circulation (leakly newsly made
blood vessels)
once in circulation, cells must be able to withstand the physiological
stress of travel in the blood and lymphatic circulation
Sometimes they bind to blood platelets=protect themselves
What is adjuvant chemotherapy?
Ans: Adjuvant chemotherapy is an approach to fighting cancer that
combines different forms of healing. Chemotherapy and radiation, or
chemotherapy and surgery are used together. Usually the chemotherapy
will be used after all of the known and visible cancer has been removed
surgically or with radiation. Adjuvant chemotherapy aims to destroy
hidden cancer cells that remain but are undetectable.
Adjuvant means additional. Adjuvant chemotherapy is given to patients
after primary treatment, when the doctor thinks there is a high risk the
cancer will return. After a primary treatment of surgery or radiation,
adjuvant chemotherapy reduces the risk of recurrence. The elimination
of undetectable microscopic cancer cells that may have traveled to other
parts of the body is the goal of adjuvant chemotherapy.
When adjuvant chemotherapy doesn't result in a full cure it does make
the intervals between a cancer relapse longer. Adjuvant chemotherapy
typically begins within three to five weeks of the surgical removal of the
cancer and has different treatment lengths depending on the cancer. For
breast cancer, the adjuvant chemotherapy is administered for three to
nine months. In the case of colon cancer, treatment rarely last more than
six months.
Most common time childhood cancers are diagnosed?
© 2025 All rights reserved
, 4 | Page
Ans: Childhood and adolescent cancers are often associated with
specific peak times of physical growth and may occur as a consequence
altered cellular regulatory mechanisms at a given time in the child or
adolescents development. Embryonal tumors most often develop before
the age of 5 years, acute lymphoblastic leukemia occurs most often in
younger children, and bone tumors occur most often in adolescents.
DES exposure prenatally
Ans: Diethylstibestrol (DES) which was prescribed by physicians to treat
spontaneous miscarriage. Identified as a transplacental chemical
carcinogen because a small percentage of the daughters of the women
who took DES developed adenocarcinomas or the vagina and cervix.
Where do most childhood cancers arise from?
Ans: Most childhood and adolescent cancers arise from the mesodermal
germ layer that gives rise to the connective tissue, bone, cartilage,
muscle, blood, blood vessels, gonads, kidney, and the lymphatic system.
Leukemia and brain tumors account for 61% of childhood cancers.
Pediatric cancers and the N-myc oncogene.
Ans: Oncogenes and tumor suppressor genes are associated with the
development of childhood cancer. Proto-oncogenes code for proteins
that help regulate normal cell growth and differentiation. If mutated,
proto-oncogenes become oncogenes that help to turn normal cells into
cancer cells. Changes produced by specific oncogenes cause the cell
cycle to become dysregulated. An example of an oncogene identified in
pediatric cancer is N-myc,which is involved in neuroblastoma and
glioblastoma. Tumor-suppressor genes arise from genes that normally
suppress cancer cell proliferation but have lost their suppressor
function, thus leading to uncontrolled growth. Some childhood cancers
identified with tumor-suppressor genes include osteosarcoma, leukemia,
rhabdomyosarcoma, retinoblastoma, and Wilms tumor.
Gland responsible for thermoregulation and cooling?
Ans: The eccrine sweat glands are distributed over the body, with the
greatest numbers in the palms of the hands, soles of the feet, and
forehead. These secretions are important in thermoregulation and
cooling of the body through evaporation.
© 2025 All rights reserved
NU 545 Unit 7 Questions and Answers
Describe the specific chromosomal abnormality responsible for
Down Syndrome
Ans: The most well known aneuploidy (those that do not contain a
multiple of 23 chromosomes) in an autosome is trisomy of the 21st
chromosome. J. Langdon Down 1st described the the disease in 1866.
Down syndrome is seen in 1 in 800 births. IQ's between 25 and 70. Facial
features: low nasal bridge, epicentral folds, protruding tongue, and flat
low set ears. Congenital heart defects in 1/3 to 1/2 of live born children.
Decreased ability to fight respiratory conditions and an increased
susceptibility to leukemia. By age 40 symptoms resembling Alzheimer
develop. 97% of Down Syndrome's cases are caused by nondisjunction
during the formation of one of the parent's gametes or during early
embryonic development. 3% from translocations. Risk increases with
maternal age.
Causes of mental retardation.
Ans: Chromosomal abnormalities.
What gene abnormality causes cystic fibrosis?
Ans: Like autosomal dominant diseases, those caused by autosomal
recessive alleles are rare in populations, although the number of carriers
for recessive diseases can be high. The most common lethal recessive
disease in white children, cystic fibrosis, occurs in about 1 in 2500
births. Approximately 1 in 25 whites carries one copy of an allele that
can cause cystic fibrosis (see Chapter 36). Because an individual must be
homozygous for a recessive allele to express thedisease, the carriers are
phenotypically normal. Because most recessive alleles are maintained
innormal carriers, they are able to survive in the population from one
generation to the next. As with many autosomal dominant diseases,
many autosomal recessive diseases are characterized by delayed age of
onset, incomplete penetrance, and variable expressivity.
How is a recessive gene inherited?
© 2025 All rights reserved
, 2 | Page
Ans: Autosomal recessive diseases occur when both parents are carriers
of the same disease and their child inherits an altered gene from each of
them. Children of carrier parents have:A 25% chance of inheriting two
altered genes and developing the disease.
Inheritance of Hemophilia A?
Ans: Hemophilia A and hemophilia B are inherited in an X-linked
recessive pattern. The genes associated with these conditions are located
on the X chromosome, which is one of the two sex chromosomes. In
males (who have only one X chromosome), one altered copy of the gene
in each cell is sufficient to cause the condition. In females (who have two
X chromosomes), a mutation would have to occur in both copies of the
gene to cause the disorder. Because it is unlikely that females will have
two altered copies of this gene, it is very rare for females to have
hemophilia. A characteristic of X-linked inheritance is that fathers cannot
pass X-linked traits to their sons.
Inheritance of Hemophilia A?
Ans: In X-linked recessive inheritance, a female with one altered copy of
the gene in each cell is called a carrier. Carrier females have about half
the usual amount of coagulation factor VIII or coagulation factor IX,
which is generally enough for normal blood clotting. However, about 10
percent of carrier females have less than half the normal amount of one
of these coagulation factors; these individuals are at risk for abnormal
bleeding, particularly after an injury, surgery, or tooth extraction.
Risk factors for DM II; why is obesity an important risk factor for
DM II?
Ans: An important risk factor is TCF7L2 which encodes a transcription
factor involved in the secretion of insulin. Another association has been
found between a common allele of the gene that incomes peroxisome
proliferator-activated receptor gamma (PPAR-y), a nuclear receptor that is
involved in adipocyte differentiation and glucose metabolism. This
receptor is the target of thiazolidinediones (TZD's) a class of drugs
commonly used to increase insulin sensitivity in those with type 2
diabetes. The 2 most important risk factors for DM II are positive family
history and obesity; the latter increases insulin resistance.
Definition of carcinoma
© 2025 All rights reserved
, 3 | Page
Ans: Cancer arising from in epithelial cells
How do cancer cells gain access to the circulation?
Ans: cells gain access to circulation through new tumor-associated blood
vessels or angiongesis
Mobile tumor cells are able to enter circulation (leakly newsly made
blood vessels)
once in circulation, cells must be able to withstand the physiological
stress of travel in the blood and lymphatic circulation
Sometimes they bind to blood platelets=protect themselves
What is adjuvant chemotherapy?
Ans: Adjuvant chemotherapy is an approach to fighting cancer that
combines different forms of healing. Chemotherapy and radiation, or
chemotherapy and surgery are used together. Usually the chemotherapy
will be used after all of the known and visible cancer has been removed
surgically or with radiation. Adjuvant chemotherapy aims to destroy
hidden cancer cells that remain but are undetectable.
Adjuvant means additional. Adjuvant chemotherapy is given to patients
after primary treatment, when the doctor thinks there is a high risk the
cancer will return. After a primary treatment of surgery or radiation,
adjuvant chemotherapy reduces the risk of recurrence. The elimination
of undetectable microscopic cancer cells that may have traveled to other
parts of the body is the goal of adjuvant chemotherapy.
When adjuvant chemotherapy doesn't result in a full cure it does make
the intervals between a cancer relapse longer. Adjuvant chemotherapy
typically begins within three to five weeks of the surgical removal of the
cancer and has different treatment lengths depending on the cancer. For
breast cancer, the adjuvant chemotherapy is administered for three to
nine months. In the case of colon cancer, treatment rarely last more than
six months.
Most common time childhood cancers are diagnosed?
© 2025 All rights reserved
, 4 | Page
Ans: Childhood and adolescent cancers are often associated with
specific peak times of physical growth and may occur as a consequence
altered cellular regulatory mechanisms at a given time in the child or
adolescents development. Embryonal tumors most often develop before
the age of 5 years, acute lymphoblastic leukemia occurs most often in
younger children, and bone tumors occur most often in adolescents.
DES exposure prenatally
Ans: Diethylstibestrol (DES) which was prescribed by physicians to treat
spontaneous miscarriage. Identified as a transplacental chemical
carcinogen because a small percentage of the daughters of the women
who took DES developed adenocarcinomas or the vagina and cervix.
Where do most childhood cancers arise from?
Ans: Most childhood and adolescent cancers arise from the mesodermal
germ layer that gives rise to the connective tissue, bone, cartilage,
muscle, blood, blood vessels, gonads, kidney, and the lymphatic system.
Leukemia and brain tumors account for 61% of childhood cancers.
Pediatric cancers and the N-myc oncogene.
Ans: Oncogenes and tumor suppressor genes are associated with the
development of childhood cancer. Proto-oncogenes code for proteins
that help regulate normal cell growth and differentiation. If mutated,
proto-oncogenes become oncogenes that help to turn normal cells into
cancer cells. Changes produced by specific oncogenes cause the cell
cycle to become dysregulated. An example of an oncogene identified in
pediatric cancer is N-myc,which is involved in neuroblastoma and
glioblastoma. Tumor-suppressor genes arise from genes that normally
suppress cancer cell proliferation but have lost their suppressor
function, thus leading to uncontrolled growth. Some childhood cancers
identified with tumor-suppressor genes include osteosarcoma, leukemia,
rhabdomyosarcoma, retinoblastoma, and Wilms tumor.
Gland responsible for thermoregulation and cooling?
Ans: The eccrine sweat glands are distributed over the body, with the
greatest numbers in the palms of the hands, soles of the feet, and
forehead. These secretions are important in thermoregulation and
cooling of the body through evaporation.
© 2025 All rights reserved
