Genetics Overview

Definition: Study of heredity and variation in organisms.
Key Concepts:
- DNA Structure: Double helix, composed of nucleotides (adenine, thymine, cytosine, guanine).
- Genes: Segments of DNA that code for proteins; basic unit of heredity.
- Chromosomes: Structures that carry genetic information; humans have 46 (23 pairs).
- Alleles: Different versions of a gene; can be dominant or recessive.
- Mendelian Genetics: Principles of inheritance discovered by Gregor Mendel, including concepts of segregation and independent assortment.
- Genetic Mutations: Changes in DNA sequence that can lead to variation; can be beneficial, neutral, or harmful.
- Genetic Engineering: Techniques such as CRISPR used to modify organisms' genomes.

Definition: Study of the structure, function, and behavior of cells.
Key Concepts:
- Cell Theory: All living organisms are composed of cells; cells are the basic unit of life; all cells arise from pre-existing cells.
- Types of Cells:
  - Prokaryotic: Lack a nucleus and membrane-bound organelles (e.g., bacteria).
  - Eukaryotic: Have a nucleus and organelles (e.g., plants, animals).
- Cell Organelles:
  - Nucleus: Contains genetic material.
  - Mitochondria: Powerhouse of the cell, site of ATP production.
  - Ribosomes: Site of protein synthesis.
  - Endoplasmic Reticulum (ER): Involved in protein and lipid synthesis; rough ER has ribosomes, smooth ER does not.
  - Golgi Apparatus: Modifies, sorts, and packages proteins for secretion.
  - Cell Membrane: Semi-permeable barrier that regulates entry and exit of substances.
- Cell Division:
  - Mitosis: Process of cell division resulting in two identical daughter cells.
  - Meiosis: Special type of cell division that produces gametes (sperm and eggs) with half the chromosome number.

Definition: Change in the heritable traits of biological populations over successive generations.
Key Concepts:
- Natural Selection: Mechanism proposed by Charles Darwin; individuals with advantageous traits are more likely to survive and reproduce.
- Mutation: Source of genetic variation; can introduce new traits into a population.
- Gene Flow: Transfer of genetic material between populations, increasing genetic diversity.
- Genetic Drift: Random changes in allele frequencies in small populations.
- Speciation: Process by which new species arise; can occur through mechanisms like allopatric and sympatric speciation.
- Common Descent: All living organisms share a common ancestor.
- Fossil Record: Provides evidence for the history of life and evolution of species over time.

Study of heredity and variation in organisms.
DNA is structured as a double helix made of nucleotides: adenine, thymine, cytosine, guanine.
Genes are segments of DNA that encode proteins, serving as the fundamental units of heredity.
Chromosomes, which carry genetic information, are present in pairs; humans possess 46 chromosomes (23 pairs).
Alleles represent different versions of a gene, categorized as dominant or recessive.
Mendelian Genetics, derived from Gregor Mendel's work, introduces principles like segregation and independent assortment.
Genetic mutations are alterations in DNA sequences, leading to variations that can be beneficial, neutral, or harmful.
Genetic engineering utilizes methods like CRISPR to alter the genomes of organisms.

Involves the study of cell structure, function, and behavior.
Cell Theory states that all living organisms consist of cells, which are the basic units of life, and all cells come from pre-existing cells.
Two primary types of cells:
- Prokaryotic cells lack a nucleus and membrane-bound organelles (e.g., bacteria).
- Eukaryotic cells possess a nucleus and organelles, including plant and animal cells.
Key cell organelles include:
- Nucleus: Houses genetic material and regulates gene expression.
- Mitochondria: Known as the cell's powerhouse; responsible for ATP production through cellular respiration.
- Ribosomes: Sites for protein synthesis, translating messenger RNA into polypeptides.
- Endoplasmic Reticulum (ER):
  - Rough ER has ribosomes attached for protein synthesis.
  - Smooth ER is involved in lipid synthesis and detoxification processes.
- Golgi Apparatus: Modifies, sorts, and packages proteins for secretion or delivery within the cell.
- Cell Membrane: A semi-permeable boundary regulating substance entry and exit.
Cell division includes:
- Mitosis: Results in two genetically identical daughter cells for growth and repair.
- Meiosis: Specializes in producing gametes, halving the chromosome number for sexual reproduction.

Defined as the change in heritable traits within biological populations over generations.
Natural Selection, introduced by Charles Darwin, suggests that individuals with advantageous traits are more likely to survive and reproduce successfully.
Mutation serves as a critical source of genetic variation, introducing new traits into a population.
Gene Flow is the exchange of genetic material between populations, promoting genetic diversity.
Genetic Drift refers to random fluctuations in allele frequencies, particularly affecting small populations.
Speciation is the evolutionary process resulting in the formation of new species, occurring via allopatric (geographically isolated) or sympatric (same location, differing niches) mechanisms.
Common Descent posits that all living organisms share a common ancestor, highlighting evolutionary relationships.
The Fossil Record is critical for studying the history of life, providing evidence of species evolution over time.