Introduction to Genetics

Genetics

Introduction to Genetics

• Study of heredity and variation in organisms
• Examines how traits are passed from one generation to the next
• Involves the study of genes, genetic information, and genetic variation

Key Concepts

• Genotype: The genetic makeup of an individual organism
• Phenotype: The physical and behavioral characteristics of an individual organism
• Dominant: A trait that will be expressed if an individual has one copy of the dominant allele
• Recessive: A trait that will be expressed only if an individual has two copies of the recessive allele
• Homozygous: Having two copies of the same allele
• Heterozygous: Having one copy of each of two different alleles

Mendelian Genetics

• Laws of Mendelian Inheritance:
  1. Law of Segregation: Each pair of alleles separates during gamete formation
  2. Law of Independent Assortment: Alleles for different genes are sorted independently during gamete formation
  3. Law of Dominance: A dominant allele will be expressed over a recessive allele
• Punnett Square: A diagram used to predict the probability of different genotypes and phenotypes in offspring

DNA Structure and Function

• DNA (Deoxyribonucleic acid): A double-stranded molecule that contains genetic information
• Chromosomes: Thread-like structures made up of DNA and proteins
• Genes: Segments of DNA that code for specific traits or proteins
• Nucleotides: Building blocks of DNA, consisting of a sugar, phosphate, and nitrogenous base
• Base pairing: The process by which nitrogenous bases pair up to form the double helix structure of DNA

Gene Expression

• Transcription: The process of creating a complementary RNA copy from a DNA template
• Translation: The process of building a protein from an RNA sequence
• Gene regulation: The process of controlling gene expression in response to environmental cues or cellular signals

Mutations and Genetic Variation

• Mutations: Changes in the DNA sequence of an organism
• Types of mutations:
  • Point mutations: Changes in a single nucleotide
  • Frameshift mutations: Changes in the reading frame of the genetic code
  • Chromosomal mutations: Changes in the number or structure of chromosomes
• Genetic variation: The differences in DNA sequences between individuals or populations

Genetics

Introduction to Genetics

• Genetics is the study of heredity and variation in organisms, examining how traits are passed from one generation to the next
• Involves the study of genes, genetic information, and genetic variation to understand the inheritance of traits

Key Concepts

• Genotype: the complete set of genes that an individual organism possesses
• Phenotype: the physical and behavioral characteristics of an individual organism resulting from the interaction of its genotype and the environment
• Dominant trait: a trait that will be expressed if an individual has one copy of the dominant allele
• Recessive trait: a trait that will be expressed only if an individual has two copies of the recessive allele
• Homozygous: having two copies of the same allele for a particular gene
• Heterozygous: having one copy of each of two different alleles for a particular gene

Mendelian Genetics

• Laws of Mendelian Inheritance:
• Law of Segregation: each pair of alleles separates during gamete formation, resulting in each gamete receiving only one allele
• Law of Independent Assortment: alleles for different genes are sorted independently during gamete formation
• Law of Dominance: a dominant allele will be expressed over a recessive allele if an individual is heterozygous
• Punnett Square: a diagram used to predict the probability of different genotypes and phenotypes in offspring from a cross between two parents

DNA Structure and Function

• DNA (Deoxyribonucleic acid): a double-stranded molecule that contains genetic information, composed of nucleotides
• Chromosomes: thread-like structures made up of DNA and proteins, found in the nucleus of eukaryotic cells
• Genes: segments of DNA that code for specific traits or proteins
• Nucleotides: building blocks of DNA, consisting of a sugar molecule, a phosphate group, and one of four nitrogenous bases (A, C, G, and T)
• Base pairing: the process by which nitrogenous bases pair up to form the double helix structure of DNA, with A pairing with T and C pairing with G

Gene Expression

• Transcription: the process of creating a complementary RNA copy from a DNA template, occurring in the nucleus
• Translation: the process of building a protein from an RNA sequence, occurring in the cytoplasm
• Gene regulation: the process of controlling gene expression in response to environmental cues or cellular signals, involving the interaction of proteins and DNA

Mutations and Genetic Variation

• Mutations: changes in the DNA sequence of an organism, which can result in changes to the phenotype
• Types of mutations:
  • Point mutations: changes in a single nucleotide, which can be a substitution, insertion, or deletion
  • Frameshift mutations: changes in the reading frame of the genetic code, resulting in a completely different amino acid sequence
  • Chromosomal mutations: changes in the number or structure of chromosomes, affecting the entire genome
• Genetic variation: the differences in DNA sequences between individuals or populations, resulting from mutations and other genetic changes