Genetics Basics

Study Notes

DNA (Deoxyribonucleic acid): molecule that contains genetic information
- Double helix structure with sugar-phosphate backbone and nitrogenous bases (A, C, G, T)
- Each base pair is 3.4 angstroms apart
Genes: segments of DNA that code for proteins or RNA molecules
- Consist of exons (coding regions) and introns (non-coding regions)
Chromosomes: thread-like structures composed of DNA and proteins
- Humans have 23 pairs (46 total) of chromosomes

Mendelian Inheritance: principles of inheritance discovered by Gregor Mendel
- Law of Segregation: each pair of alleles separates during gamete formation
- Law of Independent Assortment: alleles for different genes are sorted independently
Autosomal Dominant: one copy of the dominant allele is enough to express the trait
Autosomal Recessive: two copies of the recessive allele are needed to express the trait
X-Linked: genes located on the X chromosome, often affecting males more severely

Mutations: changes in DNA sequence
- Point mutations: single nucleotide change
- Frameshift mutations: insertion or deletion of nucleotides
Genetic Drift: random events that change allele frequencies in a population
Gene Flow: movement of genes from one population to another
Natural Selection: differential reproduction based on variation in traits

PCR (Polymerase Chain Reaction): amplifies specific DNA sequences
DNA Sequencing: determines the order of nucleotides in a DNA molecule
Genetic Engineering: modification of an organism's genome using biotechnology
Genetic Screening: testing for genetic disorders or mutations

Genetics is the study of heredity, genes, and genetic variation, involving the transmission of traits from one generation to the next.

DNA is a double helix molecule with a sugar-phosphate backbone and nitrogenous bases (A, C, G, T) that are 3.4 angstroms apart.
DNA contains genetic information.

Genes are segments of DNA that code for proteins or RNA molecules, consisting of exons (coding regions) and introns (non-coding regions).
Chromosomes are thread-like structures composed of DNA and proteins, with humans having 23 pairs (46 total) of chromosomes.

Mendelian Inheritance principles include the Law of Segregation, where each pair of alleles separates during gamete formation, and the Law of Independent Assortment, where alleles for different genes are sorted independently.
Autosomal Dominant inheritance requires one copy of the dominant allele to express the trait.
Autosomal Recessive inheritance requires two copies of the recessive allele to express the trait.
X-Linked inheritance involves genes located on the X chromosome, often affecting males more severely.

Mutations are changes in DNA sequence, including point mutations (single nucleotide change) and frameshift mutations (insertion or deletion of nucleotides).
Genetic Drift occurs through random events that change allele frequencies in a population.
Gene Flow occurs through the movement of genes from one population to another.
Natural Selection is the process of differential reproduction based on variation in traits.

PCR (Polymerase Chain Reaction) amplifies specific DNA sequences.
DNA Sequencing determines the order of nucleotides in a DNA molecule.
Genetic Engineering involves the modification of an organism's genome using biotechnology.
Genetic Screening involves testing for genetic disorders or mutations.