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MSN 277 EXAM 2 LATEST 2023-2024 ACTUAL EXAM QUESTIONS
AND CORRECT ANSWERS |ALREADY GRADED A+
Genetics and Genomics
Quick facts:
Genes – basic unit of heredity
- Controls how cells in body function
- Produce proteins that perform only 1 specific function
- Composed of sequences of DNA – found along a person’s chromosomes
- Passed from one generation to next
Genome – complete set of DNA - Contains all of organism’s gene
- Has info for organism to build and maintain itself
Genetics – the study of genes and their role in inheritance - Determines how certain traits or conditions passfrom one generation to the next
through genes - A person’s genes can have profound impact on health and disease – more than
4k disease believed to be related to altered genes
Genomics – the study of a person’s genes - Determines how genes interact w/ other genes
- Determines how genes interact w/the person’s environment
- Studies complex diseases – typically caused by combination of genetic and
environmental factors rather than 1 single gene alteration - Helps us understand why disparities exist
o Ex: person A eats healthy and exercises but dies at young age and person
B eats unhealthy and never exercises but lives to old age based on
person’s genes
The Basics of Genetics
Genes – approx. 30k genes in each person’s genome - Has specific location on chromosome
- Controls how cellsfunction – growth, cell division, longevity, etc.
- Correct code is essential proteins are made correctly, functions perform
properly
Alleles – possible form of a gene
1) Dominant – if heterozygous for trait (possess both alleles “Bb”) dominant
is expressed
2) Recessive – not expressed if dominant allele is present
Phenotype – physical traits a person expresses – height, eye/hair color, etc.
Genotype – genetic make up of a person – comprised of all genes inherited from each
parent
Chromosomes – hangout inside cell’s nucleus – occur in pairs - Each cell contains 23 pairs
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- 1
st 22 pairs = autosomes – same in both sex - 23rd pair = sex chromosome – male determines sex of baby
- XX = female, XY = male
Deoxyribonucleic acid (DNA) – molecule that contains our unique genetic code – “recipe
book” - Genes are made up of DNA – stores genetic info
Genetic Mutations – permanent change or alteration in DNA sequence - Range in size
- Can affect single DNA block up to large segment of chromosome
- Can result in development of disease in person
- Can result in ￪ risk of disease
2 types of mutations:
1) Germline mutations – inherited from parent - Sickle cell anemia, cystic fibrosis
2) Acquired (somatic) mutations – changes that occur in DNA at any point in life - Cannot be passed on to next generation
- Mistake made as DNA isreplicating during cell division or environment factor
alters DNA
o Ex: not wearing sunscreen skin cancer
o Ex: smoking lung cancer
o Ex: chemotherapy leukemia or lymphoma
Inheritance Patterns – describes how disease istransmitted in families
4 types of patterns:
1) Autosomal dominant – only 1 copy of disease allele is necessary for individual
to be susceptible to expressing phenotype - 50% chance of inheritance
o Ex: breast cancer, ovarian cancer, Huntington’s disease, Marfan
syndrome
2) Autosomal recessive – 2 copy of disease required to be susceptible to
expressing phenotype - Parents are gene carriers
- 25% chance of 2 alleles or none
- 50% chance of 1 allele
o Ex: cystic fibrosis, sickle cell disease, Tay-Sachs disease
3) X-Linked – only 1 copy of disease allele required - Both males and females affected
- Males more severely affected
o Ex: Duchenne muscular dystrophy, hemophilia
4) Y-Linked – only on Y chromosome - Only males affected
o Ex: infertility
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Genetic Screening and Testing
Genetic screening – 1
st level of detection at risk but no symptoms or family Hx
Genetic testing – focused on individuals and families for specific reason show ￪ risk,
has symptoms or family Hx
Genetic Information Nondiscrimination Act (GINA) – federal law that protects
individuals’ discrimination w/ health insurance and employment
- Illegal for insurance companiesto request or require or use genetic info to make
decision about eligibility for health insurance
Direct-to-consumer testing – genetic tests marketed directly to consumersthrough
advertisement
Genetic technology – moving at fast pace finger print testing
Pharmacogenomics and Pharmacogenetics
Because everyone has different genetic make up, different people have different reactionsto
drugs
Pharmacogenomics – the study of genetic variation associated w/ drug response in
multiple genes
Pharmacogenetics – the study of genetic variability drug responsesrelated to variations
in single gene
Future: tailor-made drugs – development of drugs made to adapt to each individual
person’s genetic make up (personalized medication)
Gene Therapy – replacesfaulty gene or adds new gene in attempt to cure disease or improve
body’s ability to fight disease - Experimental therapy only used in pt who have disease where there is no cure
lethal or disabling disease caused by single gene deficiency - Does not prevent passing mutation to offspring
- In U.S., currently only available as clinical trial
3 focus areas:
1) Replacing – if gene is not doing its proper action
2) Inactivating – turn off gene so no longer promote disease
3) Introducing – making disease more evident to immune system because
system does not recognize disease cells
Stem Cell Therapy
Stem cell – cells from which all other cells with specialized functions are generated
can divide to form more cells called daughter cells new stem cells or specialized cells - Function isto regenerate lost tissue and restore function
- Ability to remain unspecialized or differentiate
Derived from:
1) Embryo – “pluripotent stem cells”, early stage of development (3-5 days old
blastocyst – made of approx. 150 cells total) - Used to regenerate or repair tissue in damaged/diseased organs
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2) Adult – found in small # in bone marrow or fat
- More limited in developing into various cells
- May not be as versatile or durable as embryonic stem cells had more exposure
to toxin/damages
MODULE 8
Hematologic Problems
Quick facts:
Hematology – the study of blood and blood forming tissues - Bone marrow
- Blood
- Spleen
- Lymphatic system
Hematologic system: - Helps transport O2 and CO2
- Maintains intravascular volume coagulation
- Helpsfight infection
3 main hematologic problems:
1) Anemia
2) Thrombocytopenia
3) Neutropenia
Anemia – tissues become hypoxic because they are not getting the O2 they need
A deficiency in: - # of erythrocytes (RBC) carries Hgb
- quantity or quality of hemoglobin (Hgb) Fe-rich protein that attaches to lungs
and carries O2 throughout body - volume of packed RBC (hematocrit)
3 causes of Anemia:
1) ￪ RBC production
2) Blood loss
3) ￪ RBC destruction
Diagnosis based on:
1) Complete blood count (CBC) – measures all cells that make up blood (RBC,
WBC, platelets)
2) Peripheral blood smear – looks at morphology (shape and appearance of
RBC)
3) Reticulocyte count – measures how fast reticulocytes (RBC) are made by
bone marrow and released into blood
Classified by morphology:
“cytic” = size
“chromic” = content (high or low) - Normocytic, microcytic, macrocytic
- Normochromic, hypochromic, hyperchromic