VERIFIED ANSWERS|ACTUAL EXAM| ACCURATE
SOLUTIONS WITH RATIONALES/ALREADY GRADED
A+
During cell injury caused by hypoxia, why does an increase in the osmotic pressure
within the cell occur? - ✔✔ANSWER✔✔>>b.Sodium chloride enters the cell.
In hypoxic injury, movement of fluid and ions into the cell is associated with acute failure
of metabolism and a loss of ATP production. Normally, the pump that transports sodium
ions out of the cell is maintained by the presence of ATP and ATPase, the active
transport enzyme. In metabolic failure caused by hypoxia, reduced ATP and ATPase
levels permit sodium to accumulate in the cell, whereas potassium diffuses outward.
The increase of intracellular sodium increases osmotic pressure, which draws more
water into the cell. (Transport mechanisms are described in Chapter 1.) The remaining
options do not accurately describe the cell injury that results in increased osmotic
pressure caused by hypoxia.
In childhood neuroblastoma, the N-myc oncogene undergoes which type of mutation of
normal gene to oncogene? - ✔✔ANSWER✔✔>>Gene amplification
Amplifications are the result of the duplication of a small piece of a chromosome over
and over again; consequently, instead of the normal two copies of a gene, tens or even
hundreds of copies are present. The N-myc oncogene is amplified in 25% of childhood
neuroblastoma.
Regarding type 2 diabetes, obesity is considered (for most patients) what type of risk? -
✔✔ANSWER✔✔>>Modifiable
A modifiable risk is one a person can change in order to reduce risk. Obesity is a
modifiable risk factor for many diseases including heart disease, stroke, hypertension,
and type 2 diabetes. Genetic, empirical, and relative risks are not changeable by
individuals in order to reduce their chance of developing diseases.
The BRCA1 and BRCA2 mutations increase the risk of which cancer in women? -
✔✔ANSWER✔✔>>Ovarian
BRCA1 mutations increase the risk of ovarian cancer among women (20% to 50%
lifetime risk), and BRCA2 mutations also confer an increased risk of ovarian cancer
(10% to 20% lifetime prevalence). BRCA1 and BRCA2 mutations are not currently
believed to be linked with risks of lung, uterine, or pancreatic cancers.
, The data reporting that sickle cell disease affects approximately 1 in 600 American
blacks is an example of which concept? - ✔✔ANSWER✔✔>>Prevalence
Prevalence rate is the proportion of the population affected by a disease at a specific
point in time. Thus both the incidence rate and the length of the survival period in
affected individuals determine prevalence. The incidence rate is the number of new
cases of a disease reported during a specific period (typically 1 year), divided by the
number of individuals in the population. A numerical expression representing a part of a
larger whole or proportion is considered a ratio. Any factor that increases the chance of
disease or injury is considered a risk.
The prevalence rate is the proportion of the population affected by a disease at a
specific point in time. Thus both the incidence rate and the length of the survival period
in affected individuals determine prevalence. The term "relativity" is not related to
disease statistics. Survivability would refer to the chances of a person being able to
survive a specific disease and is also not related to the question. The incidence rate is
the number of new cases of a disease reported during a specific period (typically 1 year)
divided by the number of individuals in the population.
Traits caused by the combined effects of multiple genes are referred to by which term? -
✔✔ANSWER✔✔>>Polygenic
Traits in which variation is thought to be caused by the combined effects of multiple
genes are polygenic, meaning many genes. Multifocal means relating to or arising from
many points. Modifiable refers to the changeability of something. Involuntary suggests
being out of the control of someone or something.
What are the two most important risk factors for type 2 diabetes? -
✔✔ANSWER✔✔>>Obesity and positive family history
The two most important risk factors for type 2 diabetes are positive family history and
obesity. Autoantibodies and human leukocyte antigen associations are not believed to
be important risk factors for this form of diabetes.
What does the student learn about pleomorphic cells? - ✔✔ANSWER✔✔>>They have
different sizes and shapes.
In contrast to normal cells, which are uniform in size and shape, cancer cells are of
variable size and shape, known as "pleomorphic."
What is the technique for prenatal diagnosis of chromosomal abnormalities at 10 to 12
weeks' gestation? - ✔✔ANSWER✔✔>>Chorionic villus sampling consists of extracting
a small amount of villous tissuedirectly from the chorion. This procedure can be
performed at10 weeks' gestation and does not require in vitro culturing of cells;sufficient
numbers are directly available in the extractedtissue. Thus the procedure allows
prenatal diagnosis at approximately 3months' gestation rather than at nearly 4 months'
gestation which is generally when amniocentesis is performed. Gene mapping and
linkage analysis are not performed exclusively on women who are 10 weeks' pregnant.
Which cancer originates from connective tissue? - ✔✔ANSWER✔✔>>Osteogenic
sarcoma