Cell Structure, Genetics, and Evolution

Cell Theory: All living organisms are composed of cells; the cell is 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: Nucleus present, larger, more complex (e.g., plants, animals).
Organelles:
- Nucleus: Contains genetic material (DNA).
- Mitochondria: Powerhouse of the cell, site of ATP production.
- Ribosomes: Protein synthesis.
- Endoplasmic Reticulum: Rough (with ribosomes) and smooth (lipid synthesis).
- Golgi Apparatus: Modifies, sorts, and packages proteins.

DNA Structure: Double helix, composed of nucleotides (A, T, C, G).
Gene Expression:
- Transcription: DNA to RNA.
- Translation: RNA to protein.
Mendelian Inheritance:
- Dominant and recessive traits.
- Punnett Squares for predicting genetic crosses.

Natural Selection: Process by which 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.
Evidence for Evolution:
- Fossil record.
- Comparative anatomy (homologous structures).
- Molecular biology (genetic similarities).

Ecosystems: Interactions between living organisms and their environment.
Biomes: Major ecological community types (e.g., tundra, rainforest).
Food Chains and Webs:
- Trophic levels: Producers, consumers, decomposers.
Population Dynamics: Factors affecting population size and growth (birth rate, death rate, immigration, emigration).

Body Systems:
- Circulatory: Transports blood and nutrients.
- Respiratory: Gas exchange (O2 and CO2).
- Digestive: Breaks down food for energy.
- Nervous: Controls body functions via signals.
Homeostasis: Maintaining stable internal conditions (temperature, pH, etc.).

Photosynthesis: Process by which plants convert light energy into chemical energy (glucose).
Plant Structure:
- Roots: Absorb water and nutrients.
- Stems: Support and transport.
- Leaves: Site of photosynthesis.
Reproduction: Sexual (flowers, seeds) and asexual (cuttings, runners).

Animal Classification: Kingdom Animalia, divided into invertebrates and vertebrates.
Animal Behavior: Study of how animals interact with their environment (instincts, learned behaviors).
Adaptations: Traits that enhance survival and reproduction in specific environments.

Cell Theory: Foundation of biology stating all organisms are cellular, the cell is the life unit, and all cells originate from existing cells.
Prokaryotic Cells: Lack a nucleus, smaller and simpler, primarily represented by bacteria.
Eukaryotic Cells: Contain a nucleus, larger and more complex, encompassing plants and animals.
Key Organelles:
- Nucleus: Houses DNA, the genetic blueprint of organisms.
- Mitochondria: Known as the cell's powerhouse, responsible for ATP synthesis.
- Ribosomes: Sites for protein synthesis, essential for cellular functions.
- Endoplasmic Reticulum (ER):
  - Rough ER: Studded with ribosomes, involved in protein synthesis.
  - Smooth ER: Lacks ribosomes, specializes in lipid synthesis.
- Golgi Apparatus: Function in modifying, sorting, and packaging proteins for secretion or use within the cell.

DNA Structure: A double helix formed by nucleotide pairs (adenine, thymine, cytosine, guanine).
Gene Expression Process:
- Transcription: Converting DNA sequences into mRNA.
- Translation: Synthesis of proteins from mRNA sequences.
Mendelian Inheritance Principles: Features of dominant and recessive traits with predictive power through Punnett Squares.

Natural Selection: Mechanism by which more adaptive organisms survive and reproduce effectively.
Speciation: The emergence of new species through evolutionary processes.
Evidence Supporting Evolution:
- Fossil Record: Documentation of past life forms and their progression.
- Comparative Anatomy: Study of homologous structures clarifying evolutionary relationships.
- Molecular Biology: Analysis of genetic similarities across species supporting interconnectedness.

Ecosystems: Complex interactions between biotic and abiotic components, shaping environments.
Biomes: Large ecological areas with distinct climates and unique flora and fauna (e.g., tundra, rainforest).
Food Chains and Webs: Illustrate energy transfer among trophic levels including producers, consumers, and decomposers.
Population Dynamics: Influenced by factors like birth rates, death rates, immigration, and emigration determining population changes.

Body Systems:
- Circulatory System: Circulates blood, delivering nutrients and oxygen.
- Respiratory System: Facilitates gas exchange of oxygen and carbon dioxide.
- Digestive System: Breaks down food into energy and nutrients.
- Nervous System: Coordinates body functions through signaling.
Homeostasis: The process of maintaining internal stability (e.g., temperature, pH levels).

Bacteria: Prokaryotic organisms; can be beneficial, such as gut flora, or harmful pathogens.
Viruses: Acellular entities that require host cells for replication and survival.
Fungi: Eukaryotic decomposers that can play beneficial roles or act as pathogens.

Photosynthesis: Mechanism by which plants convert light energy into glucose, essential for energy.
Plant Structure:
- Roots: Absorb essential water and nutrients from the soil.
- Stems: Provide support and facilitate nutrient transportation.
- Leaves: Primary site for photosynthesis, capturing sunlight.
Plant Reproduction: Can occur sexually via flowers and seeds, or asexually through methods like cuttings and runners.

Animal Classification: The Kingdom Animalia, categorized into invertebrates (lack spinal column) and vertebrates (possess a spinal column).
Animal Behavior: Examination of how animals interact with their environment, including instinctual and learned behaviors.
Adaptations: Characteristics that enhance survival and reproductive success in specific habitats.