Genetic Variation and its Sources

Sources of Genetic Variation:
- Mutation: changes in DNA sequence
- Genetic recombination: crossing over and independent assortment during meiosis
- Gene flow: movement of genes between populations
- Genetic drift: random changes in allele frequency
Types of Genetic Variation:
- Cytogenic variation: changes in chromosome number or structure
- Molecular variation: changes in DNA sequence
Consequences of Genetic Variation:
- Increased fitness and adaptation to environment
- Evolution of new species
- Disease and disorder susceptibility

Cell Structure:
- Plasma membrane: semi-permeable membrane separating cell from environment
- Cytoplasm: jelly-like substance inside cell membrane
- Nucleus: contains genetic material (DNA)
- Mitochondria: site of cellular respiration
- Endoplasmic reticulum (ER): involved in protein synthesis and transport
- Ribosomes: site of protein synthesis
Cellular Transport:
- Passive transport: movement of molecules from high to low concentration
  - Diffusion
  - Osmosis
- Active transport: movement of molecules from low to high concentration
  - Requires energy input

Definition: process by which a new species emerges from an existing one
Mechanisms of Speciation:
- Geographic isolation: physical barrier separating populations
- Reproductive isolation: inability of populations to interbreed
- Ecological isolation: adaptations to different environments
Types of Speciation:
- Allopatric speciation: speciation due to geographic isolation
- Sympatric speciation: speciation within same geographic area
Evidence for Speciation:
- Morphological differences: distinct physical characteristics
- Reproductive barriers: inability to produce fertile offspring

Mutation: changes in DNA sequence, resulting in new alleles
Genetic recombination: crossing over and independent assortment during meiosis, increasing genetic diversity
Gene flow: movement of genes between populations, altering allele frequency
Genetic drift: random changes in allele frequency, leading to loss or fixation of alleles
Cytogenic variation: changes in chromosome number or structure, affecting gene expression
Molecular variation: changes in DNA sequence, altering gene function
Consequences of genetic variation: increased fitness and adaptation to environment, evolution of new species, and disease and disorder susceptibility

Plasma membrane: semi-permeable membrane separating cell from environment, regulating material transport
Cytoplasm: jelly-like substance inside cell membrane, providing mechanical support and medium for metabolic reactions
Nucleus: contains genetic material (DNA), regulating gene expression and cell growth
Mitochondria: site of cellular respiration, generating energy for cell
Endoplasmic reticulum (ER): involved in protein synthesis, transport, and modification
Ribosomes: site of protein synthesis, translating mRNA into polypeptides
Passive transport: movement of molecules from high to low concentration, including diffusion and osmosis
Active transport: movement of molecules from low to high concentration, requiring energy input

Definition: process by which a new species emerges from an existing one, resulting in reproductive isolation
Geographic isolation: physical barrier separating populations, leading to allopatric speciation
Reproductive isolation: inability of populations to interbreed, due to genetic or behavioral differences
Ecological isolation: adaptations to different environments, reducing gene flow
Allopatric speciation: speciation due to geographic isolation, resulting in distinct species
Sympatric speciation: speciation within same geographic area, often due to ecological isolation
Evidence for speciation: morphological differences, reproductive barriers, and genetic differences

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