General Biology: Cell Structure and Genetics

Cell Theory: All living organisms are composed of cells; the cell is the basic unit of life.
Prokaryotic vs. Eukaryotic Cells:
- Prokaryotic: No nucleus, smaller, simpler (e.g., bacteria).
- Eukaryotic: Nucleus present, larger, more complex (e.g., plants, animals).
Cell Organelles:
- Nucleus: Contains genetic material (DNA).
- Mitochondria: Powerhouse, produces ATP through respiration.
- Ribosomes: Site of protein synthesis.
- Endoplasmic Reticulum (ER): Rough (with ribosomes) and Smooth (without ribosomes) types for protein and lipid synthesis.
- Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.

DNA Structure: Double helix formed by nucleotides (A, T, C, G).
Gene Expression: Process of transcription (DNA to mRNA) and translation (mRNA to protein).
Mendelian Genetics:
- Law of Segregation: Alleles separate during gamete formation.
- Law of Independent Assortment: Genes for different traits segregate independently.
Mutations: Changes in DNA sequence, can be beneficial, harmful, or neutral.

Natural Selection: Mechanism of evolution where organisms better adapted to their environment tend to survive and reproduce.
Speciation: Formation of new and distinct species through evolutionary processes.
Phylogenetics: Study of evolutionary relationships among biological entities.

Ecosystems: Interactions between living organisms and their environment.
Food Chains and Webs: Energy flow through trophic levels (producers, consumers, decomposers).
Biomes: Large ecological areas with distinct climates and organisms (e.g., deserts, forests, tundra).

Domains of Life:
- Bacteria: Prokaryotic, unicellular organisms.
- Archaea: Prokaryotic, often extremophiles.
- Eukarya: Eukaryotic organisms (includes protists, fungi, plants, animals).
Taxonomy: Classification of living organisms into hierarchical categories (Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species).

Recombinant DNA: DNA molecules formed by combining DNA from different sources.
CRISPR: A genome editing technology that allows for precise modifications in DNA.
Applications: Medicine (gene therapy), agriculture (GMOs), and research.

Homeostasis: Maintenance of stable internal conditions in an organism.
Organ Systems: Groups of organs working together (e.g., circulatory, respiratory, digestive).
Metabolism: All chemical processes that occur within a living organism to maintain life, including catabolism (breaking down) and anabolism (building up).

Photosynthesis: Conversion of light energy into chemical energy by plants (CO2 + H2O + light → C6H12O6 + O2).
Cellular Respiration: Process of converting glucose into ATP (C6H12O6 + O2 → CO2 + H2O + ATP).

Cell Theory: Fundamental principle stating all organisms consist of one or more cells, which are the basic units of life.
Prokaryotic Cells: Lack a defined nucleus; smaller and simpler, often represented by bacteria.
Eukaryotic Cells: Contain a nucleus; larger and more complex, including plants and animals.
Key Organelles:
- Nucleus: Houses DNA, the genetic blueprint.
- Mitochondria: Known as the powerhouse of the cell, generates ATP through cellular respiration.
- Ribosomes: Responsible for protein synthesis, can be found free-floating or bound to the ER.
- Endoplasmic Reticulum (ER):
  - Rough ER: Studded with ribosomes, involved in protein production.
  - Smooth ER: Lacks ribosomes, specializes in lipid synthesis.
- Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for transport.

DNA Structure: Composed of a double helix formed by nucleotides: adenine (A), thymine (T), cytosine (C), and guanine (G).
Gene Expression: Involves two key processes:
- Transcription: Converts DNA to messenger RNA (mRNA).
- Translation: Converts mRNA into proteins.
Mendelian Genetics:
- Law of Segregation: Each organism carries two alleles for each trait, which separate during gamete formation.
- Law of Independent Assortment: Alleles for different traits segregate independently of one another.
Mutations: Alterations in the DNA sequence which may have positive, negative, or neutral outcomes.

Natural Selection: Process where organisms that are better adapted to their environment have higher survival and reproduction rates.
Speciation: Evolutionary process that leads to the emergence of new distinct species.
Phylogenetics: Studies the evolutionary interconnections between organisms and their ancestral lineages.

Ecosystems: Comprise the complex interactions between living organisms and their physical environment.
Food Chains and Webs: Illustrate energy flow through various tropic levels including producers, consumers, and decomposers.
Biomes: Large ecological areas characterized by specific climatic conditions and unique plant and animal communities (e.g., deserts, rainforest, tundra).

Domains of Life:
- Bacteria: Unicellular prokaryotic organisms.
- Archaea: Unicellular prokaryotes often found in extreme environments.
- Eukarya: Organisms with complex cells, including protists, fungi, plants, and animals.
Taxonomy: Hierarchical system classifying living organisms: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

Recombinant DNA: DNA formed by merging genetic material from different sources, used in genetic engineering.
CRISPR: Innovative genome editing tool allowing precise modifications at specific sites in the DNA.
Applications: Encompasses gene therapy in medicine, genetically modified organisms (GMOs) in agriculture, and various research practices.

Homeostasis: The process through which biological systems maintain stability despite external changes.
Organ Systems: Groups of organs that work collectively, such as circulatory, respiratory, and digestive systems.
Metabolism: Sum of all chemical processes in organisms, including catabolism (energy release) and anabolism (energy storage).

Photosynthesis: Process by which plants convert light energy into chemical energy, producing glucose and oxygen from carbon dioxide and water.
Cellular Respiration: Biochemical process that converts glucose and oxygen into carbon dioxide, water, and ATP energy.

Prioritize understanding concepts over rote memorization for better retention.
Utilize diagrams to visualize complex processes like cellular respiration.
Engage in practice questions to solidify knowledge and application of concepts.
Discuss topics with peers to deepen comprehension and explore different viewpoints.