Cell Biology and Genetics Overview

Cell Theory: All living organisms are composed of cells; cells are the basic unit of life; all cells arise from pre-existing cells.
Prokaryotic vs Eukaryotic Cells:
- Prokaryotic: No nucleus, smaller, simpler (e.g., bacteria).
- Eukaryotic: Contains a nucleus, larger, more complex (e.g., plant and animal cells).
Cell Organelles:
- Nucleus: Contains DNA, control center.
- Mitochondria: ATP production, power house of the cell.
- Ribosomes: Protein synthesis.
- Endoplasmic Reticulum: Rough (with ribosomes) and Smooth (lipid synthesis).
- Golgi Apparatus: Modifies, sorts, and packages proteins.
- Lysosomes: Digestive enzymes for waste processing.

DNA Structure: Double helix, made of nucleotides (adenine, thymine, cytosine, guanine).
Gene: Segment of DNA that codes for a protein.
Chromosomes: DNA molecules packaged with proteins; humans have 46 chromosomes.
Mendelian Genetics:
- Dominant and recessive alleles; phenotype vs. genotype.
- Punnett squares for predicting genetic crosses.
Mutation Types: Point mutations, insertions, deletions; can affect protein function.

Natural Selection: Mechanism of evolution where organisms better adapted to their environment tend to survive and produce offspring.
Common Descent: All species share a common ancestor.
Speciation: Process by which new species arise; can occur through allopatric (geographic) or sympatric (reproductive) mechanisms.

Ecosystem Levels: Individual, population, community, ecosystem, biome, biosphere.
Food Webs: Interconnected food chains; energy flow through producers, consumers, and decomposers.
Biomes: Major ecological communities defined by climate and vegetation (e.g., tundra, rainforest, desert).

Homeostasis: Maintenance of stable internal conditions (e.g., temperature, pH).
Organ Systems:
- Circulatory: Transports nutrients and oxygen.
- Respiratory: Gas exchange (oxygen and carbon dioxide).
- Digestive: Breaks down food into nutrients.
- Nervous: Controls body functions and responses.
- Endocrine: Hormonal regulation of body processes.

Photosynthesis: Process by which plants convert light energy into chemical energy (glucose); occurs in chloroplasts.
- Equation: 6 CO₂ + 6 H₂O + light energy → C₆H₁₂O₆ + 6 O₂
Plant Structures:
- Roots: Water and nutrient absorption.
- Stems: Support and transport.
- Leaves: Main site of photosynthesis.

Bacteria: Prokaryotic microorganisms; can be beneficial (gut flora) or harmful (pathogens).
Viruses: Non-living entities that require a host to replicate; consist of genetic material encased in a protein coat.
Fungi: Eukaryotic organisms; decomposers; can be unicellular (yeasts) or multicellular (molds).

Genetic Engineering: Manipulation of an organism's DNA to achieve desired traits (e.g., CRISPR technology).
Cloning: Creating a genetically identical copy of an organism.
Bioremediation: Use of organisms to remove or neutralize contaminants from the environment.

Cell Theory: Foundation of biology stating all living organisms are composed of cells, cells are the basic unit of life, and all cells originate from pre-existing cells.
Prokaryotic Cells: Lack a nucleus, are generally smaller and simpler in structure, exemplified by bacteria.
Eukaryotic Cells: Contain a nucleus, are larger and more intricate, including plant and animal cells.
Organelles:
- Nucleus: Houses DNA and functions as the control center of the cell.
- Mitochondria: Known as the cell's powerhouse, responsible for ATP production.
- Ribosomes: Sites of protein synthesis, either free-floating or attached to the endoplasmic reticulum.
- Endoplasmic Reticulum (ER): Divided into rough ER (with ribosomes, responsible for protein synthesis) and smooth ER (involved in lipid synthesis).
- Golgi Apparatus: Modifies, sorts, and packages proteins for transport.
- Lysosomes: Contain digestive enzymes for breaking down waste materials.

DNA Structure: Features a double helix formed from nucleotides: adenine, thymine, cytosine, and guanine.
Gene: A specific segment of DNA that encodes for a protein.
Chromosomes: DNA molecules bundled with proteins; humans possess 46 chromosomes in total.
Mendelian Genetics: Involves concepts like dominant and recessive alleles, and differentiates between phenotype (observable traits) and genotype (genetic makeup).
Punnett Squares: A tool used to predict the outcomes of genetic crosses.
Mutation Types: Includes point mutations, insertions, and deletions which can significantly alter protein function.

Natural Selection: The mechanism driving evolution, favoring organisms that are better adapted to their environments to survive and reproduce.
Common Descent: Theory that all species have a shared common ancestor.
Speciation: The evolutionary process where new species emerge; can happen through geographic (allopatric) isolation or reproductive (sympatric) barriers.

Ecosystem Levels: Hierarchical structure includes individual, population, community, ecosystem, biome, and biosphere.
Food Webs: Complex networks of interconnected food chains illustrating energy flow through producers, consumers, and decomposers.
Biomes: Major ecological regions characterized by specific climatic conditions and types of vegetation, such as tundra, rainforest, and desert.

Homeostasis: The biological principle of maintaining stable internal conditions, such as temperature and pH balance.
Organ Systems:
- Circulatory System: Responsible for transporting nutrients and oxygen throughout the body.
- Respiratory System: Facilitates gas exchange, primarily oxygen intake and carbon dioxide removal.
- Digestive System: Breaks down food into usable nutrients for the body.
- Nervous System: Governs body functions, processing stimuli and coordinating responses.
- Endocrine System: Regulates body processes through hormonal signals.

Photosynthesis: The process by which plants transform light energy into chemical energy (glucose), occurring within chloroplasts.
Chemical Equation: 6 CO₂ + 6 H₂O + light energy → C₆H₁₂O₆ + 6 O₂.
Plant Structures:
- Roots: Function in water and nutrient absorption.
- Stems: Provide structural support and facilitate transport of materials.
- Leaves: The primary site for photosynthesis, where light energy is converted into chemical energy.

Bacteria: Prokaryotic microorganisms that can serve beneficial roles (like gut flora) or harmful ones (pathogenic bacteria).
Viruses: Non-living agents that require a host cell to replicate; consist of genetic material encased within a protein coat.
Fungi: Eukaryotic decomposers that can be either unicellular (e.g., yeasts) or multicellular (e.g., molds).

Genetic Engineering: The process of modifying an organism's DNA to produce desired traits, exemplified by CRISPR technology.
Cloning: The creation of genetically identical organisms.
Bioremediation: Utilizing organisms to detoxify or remove environmental contaminants.