MSN 277 EXAM 2 LATEST - AL EXAM QUESTIONS

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MSN 277 EXAM 2 LATEST - AL 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 pass from 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 cells function – 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 1 / 4

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• 1 st 22 pairs = autosomes – same in both sex

• 23

rd 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 is replicating 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 is transmitted 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 2 / 4

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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 companies to request or require or use genetic info to make decision about eligibility for health insurance Direct-to-consumer testing – genetic tests marketed directly to consumers through advertisement Genetic technology – moving at fast pace finger print testing

Pharmacogenomics and Pharmacogenetics Because everyone has different genetic make up, different people have different reactions to drugs Pharmacogenomics – the study of genetic variation associated w/ drug response in multiple genes Pharmacogenetics – the study of genetic variability drug responses related 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 – replaces faulty 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 is to 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 3 / 4

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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 • Helps fight 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

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