Cell Biology and Genetics Overview

Cell Theory: All living organisms are composed of cells, and cells arise from pre-existing cells.
Types of Cells:
- Prokaryotic: Simple, no nucleus (e.g., bacteria).
- Eukaryotic: Complex, with a nucleus (e.g., plant and animal cells).
Cell Organelles:
- Nucleus: Contains genetic material (DNA).
- Mitochondria: Powerhouse of the cell, site of ATP production.
- Ribosomes: Protein synthesis.
- Endoplasmic Reticulum: Smooth (lipid synthesis) and Rough (protein synthesis).
- Golgi Apparatus: Modifies and packages proteins.

DNA Structure: Double helix composed of nucleotides (adenine, thymine, cytosine, guanine).
Gene: A segment of DNA that codes for a protein.
Alleles: Different versions of a gene.
Mendelian Genetics:
- Law of Segregation: Alleles separate during gamete formation.
- Law of Independent Assortment: Genes for different traits are inherited independently.
Genotype vs. Phenotype:
- Genotype: Genetic makeup.
- Phenotype: Observable characteristics.

Natural Selection: Mechanism of evolution where organisms better adapted to their environment tend to survive and reproduce.
Speciation: The formation of new species through evolutionary processes.
Evidence of Evolution:
- Fossil records.
- Comparative anatomy (homologous and analogous structures).
- Molecular biology (DNA comparisons).

Ecosystem: A community of living organisms and their environment.
Biomes: Large ecological areas on Earth's surface, characterized by climate and vegetation (e.g., deserts, forests).
Food Chains and Webs:
- Producers: Autotrophs (e.g., plants).
- Consumers: Heterotrophs (e.g., animals).
- Decomposers: Break down dead organic matter.

Body Systems:
- Circulatory: Transports nutrients and oxygen.
- Respiratory: Gas exchange (oxygen and carbon dioxide).
- Digestive: Breaks down food for energy.
- Nervous: Controls body functions and responses.
Homeostasis: The maintenance of stable internal conditions in the body.

Bacteria: Prokaryotic organisms, can be beneficial or pathogenic.
Viruses: Non-living infectious agents, require a host to replicate.
Fungi: Eukaryotic organisms, can decompose organic material or cause infections.

Photosynthesis: Process by which plants convert sunlight into chemical energy (glucose).
Plant Anatomy:
- Roots: Absorb water and nutrients.
- Stems: Support and transport materials.
- Leaves: Site of photosynthesis.

Innate Behaviors: Instinctive and do not require learning (e.g., reflexes).
Learned Behaviors: Acquired through experience (e.g., conditioning).
Social Structures: Hierarchical organization in animal communities (e.g., packs, colonies).

Macromolecules:
- Carbohydrates: Energy source and structural components.
- Proteins: Made of amino acids; perform a variety of functions.
- Lipids: Fats and oils; energy storage and membrane structure.
- Nucleic Acids: DNA and RNA; genetic information storage and transfer.

Cell Theory: States that all living organisms are made of cells and that these cells originate from existing cells.
Cell Types:
- Prokaryotic Cells: Characterized by their simplicity and lack of a nucleus, commonly represented by bacteria.
- Eukaryotic Cells: More complex, containing a nucleus, exemplified by plant and animal cells.
Key Organelles:
- Nucleus: Houses the cell's genetic material, DNA.
- Mitochondria: Known as the powerhouse of the cell, responsible for ATP production.
- Ribosomes: Sites of protein synthesis.
- Endoplasmic Reticulum (ER): Divided into Smooth (involved in lipid synthesis) and Rough (associated with protein synthesis).
- Golgi Apparatus: Modifies and packages proteins for transport.

DNA Structure: Consists of a double helix made up of nucleotides including adenine, thymine, cytosine, and guanine.
Gene: A specific segment of DNA that encodes a protein.
Alleles: Different forms of the same gene.
Mendelian Genetics Principles:
- Law of Segregation: Alleles separate when forming gametes.
- Law of Independent Assortment: Genes for different traits are inherited independently of one another.
Genotype vs. Phenotype:
- Genotype: The genetic constitution of an organism.
- Phenotype: The observable characteristics resulting from the genotype.

Natural Selection: A process where organisms best suited to their environment are more likely to survive and reproduce.
Speciation: Refers to how new species are formed through evolutionary mechanisms.
Evidence for Evolution:
- Fossil Records: Provide historical insights into evolutionary history.
- Comparative Anatomy: Includes homologous and analogous structures that illustrate evolutionary relationships.
- Molecular Biology: Involves DNA comparisons that hint at evolutionary connections.

Ecosystem: Comprises a community of living organisms interacting with their physical environment.
Biomes: Large ecological zones defined by climatic conditions and vegetation types, such as deserts and forests.
Food Chains and Webs:
- Producers: Autotrophs like plants that create their own energy.
- Consumers: Heterotrophs, primarily animals, that obtain energy by consuming other organisms.
- Decomposers: Organisms that break down dead organic material, returning nutrients to the ecosystem.

Body Systems Overview:
- Circulatory System: Responsible for nutrient and oxygen transport throughout the body.
- Respiratory System: Facilitates gas exchange, primarily oxygen and carbon dioxide.
- Digestive System: Breaks down food to extract energy.
- Nervous System: Controls bodily functions and responses to stimuli.
Homeostasis: The regulatory process maintaining stable internal conditions despite environmental changes.

Bacteria: Prokaryotic organisms that can be advantageous in nature or cause diseases.
Viruses: Non-living entities that need a host cell to replicate and produce infections.
Fungi: Eukaryotic organisms that play various roles, from decomposition of organic material to causing infections.

Photosynthesis: The process plants use to convert sunlight into chemical energy in the form of glucose.
Plant Anatomy:
- Roots: Function in the absorption of water and nutrients.
- Stems: Provide structural support and transport of materials.
- Leaves: The primary site for photosynthesis.

Innate Behaviors: Instinctual actions that do not require learning, such as reflexes.
Learned Behaviors: Actions developed through experience and interactions, like conditioning.
Social Structures: Hierarchies and organization within animal groups, including packs and colonies.

Macromolecules:
- Carbohydrates: Serve as energy sources and structural components within organisms.
- Proteins: Composed of amino acids, they perform a variety of crucial biological functions.
- Lipids: Include fats and oils, essential for energy storage and cell membrane structure.
- Nucleic Acids: DNA and RNA are vital for the storage and transfer of genetic information.