NURS 6501 – Week 2 Study Guide
Genetics & Genomics in Pathophysiology
Walden University | Advanced Pathophysiology
A+ Rated | Exam-Focused Notes + 10 NCLEX Practice Questions
Key Concepts in Genetics
1. DNA Structure
• Double helix made of nucleotides (A-T, C-G pairs)
• Located in the nucleus
• Replicates during interphase for cell division
2. Genes & Chromosomes
• Gene = Basic unit of inheritance
• Alleles = Different forms of a gene (dominant/recessive)
• Homozygous = Same alleles (e.g., AA), Heterozygous = Different (e.g., Aa)
• Humans have 23 pairs of chromosomes (22 autosomes, 1 sex pair)
Mutations
• Point mutation: A single nucleotide change (e.g., sickle cell)
• Frameshift mutation: Insertion/deletion shifts reading frame
• Mutagens: Radiation, chemicals, viruses (e.g., HPV)
Inheritance Patterns
Pattern Description Example
Autosomal Dominant One mutated copy causes disease Huntington’s disease
Autosomal Recessive Both copies must be mutated Cystic fibrosis
X-linked Recessive Mostly affects males Hemophilia A
Mitochondrial Maternal inheritance only Leber’s optic neuropathy
Genetics & Genomics in Pathophysiology
Walden University | Advanced Pathophysiology
A+ Rated | Exam-Focused Notes + 10 NCLEX Practice Questions
Key Concepts in Genetics
1. DNA Structure
• Double helix made of nucleotides (A-T, C-G pairs)
• Located in the nucleus
• Replicates during interphase for cell division
2. Genes & Chromosomes
• Gene = Basic unit of inheritance
• Alleles = Different forms of a gene (dominant/recessive)
• Homozygous = Same alleles (e.g., AA), Heterozygous = Different (e.g., Aa)
• Humans have 23 pairs of chromosomes (22 autosomes, 1 sex pair)
Mutations
• Point mutation: A single nucleotide change (e.g., sickle cell)
• Frameshift mutation: Insertion/deletion shifts reading frame
• Mutagens: Radiation, chemicals, viruses (e.g., HPV)
Inheritance Patterns
Pattern Description Example
Autosomal Dominant One mutated copy causes disease Huntington’s disease
Autosomal Recessive Both copies must be mutated Cystic fibrosis
X-linked Recessive Mostly affects males Hemophilia A
Mitochondrial Maternal inheritance only Leber’s optic neuropathy
