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.
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 (DNA).
- Mitochondria: Energy production (ATP).
- Ribosomes: Protein synthesis.
- Endoplasmic Reticulum: Transport and processing of proteins.
- Golgi Apparatus: Modifies, sorts, and packages proteins.
- Lysosomes: Digestion of waste materials.

DNA Structure:
- Double helix composed of nucleotides (A, T, C, G).
Key Processes:
- Replication: DNA copying for cell division.
- Transcription: DNA to RNA synthesis.
- Translation: RNA to protein synthesis.
Mendelian Genetics:
- Laws of Inheritance: Law of Segregation and Law of Independent Assortment.
- Genotype vs. Phenotype: Genetic makeup vs. observable traits.
Mutations: Changes in DNA sequence that can affect phenotype.

Natural Selection: Mechanism of evolution; organisms better adapted to their environment tend to survive and reproduce.
Speciation: Process by which new species arise, often through isolation and genetic divergence.
Evidence for Evolution:
- Fossil record.
- Comparative anatomy (homologous structures).
- Molecular biology (genetic similarities).

Ecosystems: Community of living organisms interacting with their environment.
Biomes: Major ecological communities classified by climate and vegetation (e.g., rainforest, desert).
Energy Flow:
- Producers (plants) convert sunlight into energy.
- Consumers (herbivores, carnivores) obtain energy by eating other organisms.
Biogeochemical Cycles: Recycling of nutrients in ecosystems (e.g., carbon cycle, water cycle).

Homeostasis: The process by which organisms maintain a stable internal environment (e.g., temperature regulation).
Human Systems:
- Circulatory System: Transports blood, nutrients, oxygen.
- Respiratory System: Gas exchange (oxygen in, carbon dioxide out).
- Nervous System: Controls body functions via signaling (neurons).
- Endocrine System: Regulates bodily functions through hormones.

Photosynthesis: Process by which plants convert light energy into chemical energy (glucose).
Plant Structures:
- Roots: Absorb water and nutrients.
- Stems: Support and transport nutrients.
- Leaves: Main site of photosynthesis.
Reproduction:
- Asexual: Cloning (e.g., runners, tubers).
- Sexual: Formation of seeds via pollination and fertilization.

Bacteria: Prokaryotic microorganisms with diverse roles (pathogenic, beneficial).
Viruses: Non-living entities that require a host to reproduce.
Fungi: Eukaryotic organisms that decompose organic matter and can form symbiotic relationships (e.g., mycorrhizae with plants).

Cell Theory: Fundamental principles stating that all living organisms consist of cells, the cell is the fundamental unit of life, and all cells originate from existing cells.
Types of Cells:
- Prokaryotic Cells: Simple structure without a nucleus; examples include bacteria.
- Eukaryotic Cells: Complex structure with a nucleus; examples include plants and animals.
Cell Organelles:
- Nucleus: Houses genetic material (DNA).
- Mitochondria: Responsible for ATP (energy) production.
- Ribosomes: Site of protein synthesis.
- Endoplasmic Reticulum: Functions in the transport and processing of proteins.
- Golgi Apparatus: Modifies, sorts, and packages proteins for transport.
- Lysosomes: Break down waste and cellular debris.

DNA Structure: DNA is a double helix made up of nucleotides, including adenine (A), thymine (T), cytosine (C), and guanine (G).
Key Processes:
- Replication: The process by which DNA is copied in preparation for cell division.
- Transcription: Conversion of DNA into RNA.
- Translation: Process in which RNA is used to synthesize proteins.
Mendelian Genetics:
- Laws of Inheritance: Includes the Law of Segregation and the Law of Independent Assortment.
- Genotype vs. Phenotype: Distinction between genetic makeup (genotype) and observable traits (phenotype).
- Mutations: Alterations in DNA sequences that may impact phenotypic traits.

Natural Selection: A key mechanism of evolution where individuals with advantageous traits tend to survive and reproduce more successfully.
Speciation: The emergence of new species typically through the processes of isolation and genetic divergence.
Evidence for Evolution:
- Fossil records providing historical context.
- Comparative anatomy, highlighting homologous structures among species.
- Molecular biology, examining genetic similarities across different organisms.

Ecosystems: Comprises communities of living organisms and their interactions with the environment.
Biomes: Major ecological communities characterized by specific climates and vegetation types such as rainforests and deserts.
Energy Flow:
- Producers: Organisms like plants that convert sunlight into usable energy.
- Consumers: Entities including herbivores and carnivores that gain energy by consuming other organisms.
Biogeochemical Cycles: Processes that recycle nutrients within ecosystems, including cycles such as the carbon cycle and water cycle.

Homeostasis: The mechanism by which organisms regulate their internal environment, including temperature control.
Human Systems:
- Circulatory System: Responsible for the movement of blood, nutrients, and oxygen throughout the body.
- Respiratory System: Facilitates gas exchange, taking in oxygen and expelling carbon dioxide.
- Nervous System: Governs bodily functions through signaling via neurons.
- Endocrine System: Regulates bodily functions through hormone production and secretion.

Photosynthesis: The process through which plants transform light energy into chemical energy, producing glucose.
Plant Structures:
- Roots: Function to absorb water and essential nutrients from the soil.
- Stems: Serve to support the plant structure and facilitate nutrient transport.
- Leaves: Main area where photosynthesis occurs.
Reproduction:
- Asexual Reproduction: Includes processes like cloning through runners or tubers.
- Sexual Reproduction: Involves seed formation via pollination and fertilization.

Bacteria: Prokaryotic microorganisms that fulfill various roles, which can be pathogenic or beneficial to ecosystems.
Viruses: Non-living entities that require a host cell for their reproduction.
Fungi: Eukaryotic organisms that decompose organic matter and often engage in symbiotic relationships, such as forming mycorrhizae with plant roots.