Cell Biology and Genetics Overview

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

DNA Structure: Double helix, composed of nucleotides (adenine, thymine, cytosine, guanine).
Gene Expression:
- Transcription: DNA to RNA.
- Translation: RNA to protein.
Mendelian Genetics:
- Laws of segregation and independent assortment.
- Dominant and recessive alleles.
Mutations: Changes in DNA sequence that can lead to genetic diversity.

Natural Selection: Process by which organisms better adapted to their environment tend to survive and produce more offspring.
Evidence of Evolution:
- Fossil records.
- Comparative anatomy (homologous and analogous structures).
- Molecular biology (DNA similarities).
Speciation: Formation of new and distinct species in the course of evolution.

Levels of Organization:
- Individual, population, community, ecosystem, biosphere.
Energy Flow:
- Producers (autotrophs) convert sunlight into energy.
- Consumers (heterotrophs) feed on producers or other consumers.
- Decomposers recycle nutrients back to the ecosystem.
Biomes: Large regions characterized by specific climate conditions (e.g., desert, rainforest).

Organ Systems:
- Circulatory: Transports blood and nutrients.
- Respiratory: Gas exchange, oxygen intake.
- Digestive: Breaks down food, nutrient absorption.
- Nervous: Controls body functions, responses to stimuli.
Homeostasis: The maintenance of a stable internal environment (e.g., temperature regulation, pH balance).

Cellular Respiration: Process by which cells convert glucose and oxygen into energy (ATP), carbon dioxide, and water.
Photosynthesis: Process by which plants convert sunlight, carbon dioxide, and water into glucose and oxygen.

Bacteria: Prokaryotic organisms, can be beneficial (e.g., gut flora) or pathogenic.
Viruses: Infectious agents that require a host cell to replicate.
Fungi: Eukaryotic organisms, play a role in decomposition and nutrient cycling.

Genetic Engineering: Modification of an organism's DNA (e.g., CRISPR technology).
Cloning: Producing genetically identical organisms.
Bioremediation: Use of organisms to remove or neutralize contaminants from the environment.

Cell Theory: Fundamental principles stating all living organisms consist of cells, cells serve as the fundamental unit of life, and new cells emerge from existing cells.
Cell Types:
- Prokaryotic: Simplistic cell structure lacking a nucleus, typical examples include bacteria.
- Eukaryotic: More complex cells with a defined nucleus, found in organisms like plants and animals.
Organelles Functions:
- Nucleus: Houses genetic material (DNA).
- Mitochondria: Key site for ATP (energy) production.
- Ribosomes: Essential for protein synthesis, either free-floating or attached to the endoplasmic reticulum.
- Endoplasmic Reticulum (ER): Two types—rough (studied with ribosomes, focuses on protein synthesis) and smooth (lipid synthesis).
- Golgi Apparatus: Modifies, sorts, and packages proteins for secretion or use within the cell.

DNA Structure: Composed of a double helix structure, consisting of four nucleotides: adenine, thymine, cytosine, and guanine.
Gene Expression:
- Transcription: Process of converting DNA sequences into RNA.
- Translation: RNA is translated into proteins.
Mendelian Genetics:
- Governs inheritance patterns through laws of segregation and independent assortment, identifying the roles of dominant and recessive alleles.
Mutations: Genetic sequence alterations leading to variations, which can contribute to genetic diversity in populations.

Natural Selection: Mechanism by which organisms with favorable adaptations are more likely to survive and reproduce.
Evidence of Evolution: Ascertainable through:
- Fossil Records: Show chronological existence of species.
- Comparative Anatomy: Study of anatomical similarities and differences among species, including homologous and analogous structures.
- Molecular Biology: Examination of DNA similarities and genetic evidence among organisms.
Speciation: Development of new species through evolutionary processes.

Levels of Organization: Ranges from individual organisms to populations, communities, ecosystems, and the broader biosphere.
Energy Flow:
- Producers: Autotrophs that convert sunlight into energy.
- Consumers: Heterotrophs that consume producers or other consumers to gain energy.
- Decomposers: Organisms that break down organic matter, recycling nutrients back into ecosystems.
Biomes: Major ecological regions defined by distinct climate conditions, such as deserts and rainforests.

Organ Systems:
- Circulatory System: Delivers oxygen and nutrients throughout the body.
- Respiratory System: Facilitates gas exchange, primarily oxygen intake and carbon dioxide expulsion.
- Digestive System: Responsible for food breakdown and nutrient absorption.
- Nervous System: Coordinates body activities and responses to environmental stimuli.
Homeostasis: Process by which the body maintains stable internal conditions, including temperature and pH balance.

Cellular Respiration: Biochemical process converting glucose and oxygen into ATP, alongside carbon dioxide and water as byproducts.
Photosynthesis: Plants use sunlight, carbon dioxide, and water to create glucose and release oxygen, fundamental for energy production.

Bacteria: Diverse prokaryotic organisms; some are beneficial (e.g., gut bacteria), while others can cause illness (pathogenic).
Viruses: Infectious entities that replicate only within host cells, exploiting cellular machinery.
Fungi: Eukaryotic organisms that decompose organic matter and contribute to nutrient cycling.

Genetic Engineering: Involves alterations to an organism's DNA for desired traits, exemplified by CRISPR technology.
Cloning: Technique for creating genetically identical organisms through somatic cell nuclear transfer.
Bioremediation: Utilizing microorganisms to detoxify or eliminate pollutants from the environment.