Cell Biology and Genetics Principles

Cell Theory
- All living organisms are composed of cells.
- The cell is the basic unit of life.
- All cells arise from pre-existing cells.
Types of Cells
- Prokaryotic: Simple, no nucleus (e.g., bacteria).
- Eukaryotic: Complex, with a nucleus (e.g., plants, animals).
Cell Organelles
- Nucleus: Contains genetic material.
- Mitochondria: Powerhouse of the cell, ATP production.
- Ribosomes: Protein synthesis.
- Endoplasmic Reticulum (ER): Protein and lipid synthesis; rough ER has ribosomes.
- Golgi Apparatus: Modifies and packages proteins.
- Lysosomes: Digests waste materials.

DNA Structure
- Double helix made of nucleotides: adenine, thymine, cytosine, guanine.
Gene Expression
- Transcription: DNA to mRNA in the nucleus.
- Translation: mRNA to protein at ribosomes.
Mendelian Genetics
- Law of Segregation: Alleles separate during gamete formation.
- Law of Independent Assortment: Genes for different traits segregate independently.

Natural Selection
- Mechanism of evolution where organisms better adapted to their environment tend to survive and produce more offspring.
Speciation
- Formation of new and distinct species in the course of evolution.

Levels of Organization
- Individual, Population, Community, Ecosystem, Biosphere.
Biomes
- Major ecological communities (e.g., desert, rainforest, tundra).
Ecosystem Dynamics
- Energy flow (food chains/webs), nutrient cycling.

Body Systems
- Circulatory System: Transports blood and nutrients.
- Respiratory System: Gas exchange (oxygen and carbon dioxide).
- Digestive System: Breaks down food for energy.
Homeostasis
- Maintenance of stable internal conditions (e.g., temperature, pH).

Bacteria
- Prokaryotic, diverse metabolic pathways, roles in nutrient cycling.
Viruses
- Acellular, parasitic entities that require a host to replicate.
Fungi
- Eukaryotic, decomposers, cell walls made of chitin.

Photosynthesis
- Process by which plants convert light energy into chemical energy (glucose).
- Equation: 6CO2 + 6H2O → C6H12O6 + 6O2.
Plant Structure
- Roots: Absorption of water and nutrients.
- Stems: Support, transport of materials.
- Leaves: Site of photosynthesis.

Animal Classification
- Kingdom Animalia, divided into phyla (e.g., Chordata, Arthropoda).
Animal Behavior
- Innate vs. learned behavior.
- Social structures and communication in species.

Biodiversity
- Variety of life in the world, importance for ecosystem resilience.
Threats to Biodiversity
- Habitat destruction, pollution, climate change, invasive species.

These study notes cover fundamental concepts and facts within the field of biology, providing a solid overview for further study or review.

Cell Theory indicates that all living organisms consist of cells, which are the fundamental units of life, and all cells originate from existing cells.
Prokaryotic cells lack a nucleus and are simpler in structure, exemplified by bacteria, while eukaryotic cells have a nucleus and are found in organisms such as plants and animals.
The nucleus houses genetic material, mitochondria serve as the powerhouse of the cell through ATP production, and ribosomes are essential for protein synthesis.
The Endoplasmic Reticulum (ER) facilitates the synthesis of proteins and lipids; rough ER has ribosomes attached to it, while the Golgi Apparatus modifies and packages proteins for transport.
Lysosomes function as the digestive system of the cell, breaking down waste materials.

DNA is structured as a double helix comprising nucleotides: adenine, thymine, cytosine, and guanine.
Gene expression involves transcription (conversion of DNA to mRNA) in the nucleus, followed by translation (conversion of mRNA to protein) at ribosomes.
Mendelian genetics features the Law of Segregation, where alleles separate during gamete formation, and the Law of Independent Assortment, which states that different genes segregate independently of one another during the formation of gametes.

Natural selection is the primary mechanism of evolution, favoring organisms that are better adapted to their environment, leading to greater survival and reproduction.
Speciation refers to the evolutionary process through which new and distinct species arise.

Organisms are organized into hierarchical levels: Individual, Population, Community, Ecosystem, and Biosphere.
Biomes represent major ecological communities, such as deserts, rainforests, and tundras.
Ecosystem dynamics include energy flow through food chains and webs, as well as the cycling of nutrients within ecosystems.

The circulatory system is responsible for transporting blood and nutrients throughout the body.
The respiratory system facilitates gas exchange, primarily oxygen and carbon dioxide.
The digestive system breaks down food into energy and nutrients necessary for body function.
Homeostasis is the process by which organisms maintain stable internal conditions, including temperature and pH balance.

Bacteria are prokaryotic organisms with diverse metabolic pathways, playing critical roles in the cycling of nutrients in ecosystems.
Viruses are acellular and parasitic, requiring a host cell for replication.
Fungi, classified as eukaryotic organisms, act as decomposers and possess cell walls made of chitin.

Photosynthesis is the process that enables plants to convert light energy into chemical energy, resulting in glucose production, with the equation: 6CO2 + 6H2O → C6H12O6 + 6O2.
Plant structures include roots for water and nutrient absorption, stems for support and material transport, and leaves, which serve as the site for photosynthesis.

Animal classification is organized into the Kingdom Animalia, divided into various phyla including Chordata (vertebrates) and Arthropoda (invertebrates).
Animal behavior encompasses innate and learned behaviors, as well as the social structures and communication methods prevalent within species.

Biodiversity refers to the variety of life forms in ecosystems, which is crucial for maintaining ecosystem resilience and stability.
Threats to biodiversity include habitat destruction, pollution, climate change, and the introduction of invasive species, all of which jeopardize species survival and ecological balance.