Cell Biology and Genetics Overview

Cell Biology

Cell Theory:
- All living things are composed of cells.
- Cells are the basic unit of life.
- All cells arise from pre-existing cells.
Types of Cells:
- Prokaryotic: No nucleus, smaller, simpler (e.g., bacteria).
- Eukaryotic: Nucleus present, larger, more complex (e.g., animal and plant cells).
Cell Organelles:
- Nucleus: Contains DNA, coordinates cell activities.
- Mitochondria: Powerhouse of the cell, energy production (ATP).
- Ribosomes: Protein synthesis.
- Endoplasmic Reticulum:
  - Rough ER: Studded with ribosomes, synthesizes proteins.
  - Smooth ER: Synthesizes lipids, detoxifies.
- Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.
- Lysosomes: Digestive enzymes, waste processing.
- Chloroplasts: Photosynthesis (in plant cells).

Genetics

DNA Structure: Double helix, composed of nucleotides (A, T, C, G).
Gene: A segment of DNA that codes for a protein or trait.
Alleles: Different versions of a gene.
Mendelian Inheritance:
- Dominant and recessive traits.
- Law of Segregation: Alleles separate during gamete formation.
- Law of Independent Assortment: Genes for different traits segregate independently.

Evolution

Natural Selection:
- Mechanism of evolution; organisms better adapted to their environment tend to survive and reproduce.
Common Descent: All living organisms share a common ancestor.
Speciation: Process by which new species arise.

Ecology

Ecosystem: Community of living organisms interacting with their environment.
Biomes: Large ecological areas (e.g., tundra, rainforest) defined by climate and vegetation.
Food Chains/Webs:
- Producers (autotrophs) → Consumers (heterotrophs) → Decomposers.
Biodiversity: Variety of life in an ecosystem; important for resilience and adaptation.

Human Biology

Organ Systems:
- Circulatory, respiratory, digestive, nervous, muscular, skeletal, immune, endocrine, reproductive, integumentary, urinary.
Homeostasis: Maintenance of stable internal conditions (temperature, pH, electrolyte balance).
Metabolism: Chemical reactions in the body to maintain life (catabolism and anabolism).

Microbiology

Bacteria: Prokaryotic microorganisms, classified by shape (cocci, bacilli, spirilla).
Viruses: Non-living entities that require a host to replicate.
Fungi: Eukaryotic organisms, decomposers, important in biotechnology.

Plant Biology

Photosynthesis: Process by which plants convert light energy into chemical energy (glucose).
Plant Structure:
- Roots: Absorption of water and nutrients.
- Stems: Support and transport.
- Leaves: Main site of photosynthesis.
Reproduction:
- Asexual (cloning, budding).
- Sexual (pollination, seed formation).

Animal Behavior

Innate Behavior: Instinctive, genetically inherited actions (e.g., reflexes).
Learned Behavior: Acquired through experience (e.g., conditioning).
Social Behavior: Interaction among individuals, including cooperation, competition, and mating.

Biotechnology

Genetic Engineering: Manipulation of an organism’s DNA to achieve desired traits.
CRISPR-Cas9: Tool for editing genes with precision.
Stem Cells: Undifferentiated cells with the potential to develop into various cell types.

This structured summary encapsulates fundamental concepts across various biology disciplines.

Cell Biology

Cell Theory:
- All living organisms consist of one or more cells.
- Cells are the fundamental unit of life, performing essential functions.
- New cells are generated from existing cells through division.
Types of Cells:
- Prokaryotic: Characterized by absence of a nucleus; smaller and simpler structures, exemplified by bacteria.
- Eukaryotic: Contain a nucleus; larger and more complex, found in animals and plants.
Cell Organelles:
- Nucleus: Houses genetic material (DNA) and regulates cellular activities.
- Mitochondria: Known as the cell’s powerhouse; responsible for producing energy in the form of ATP.
- Ribosomes: Sites where proteins are synthesized, either free-floating or attached to the endoplasmic reticulum.
- Endoplasmic Reticulum (ER):
  - Rough ER: Embedded with ribosomes, involved in protein synthesis and processing.
  - Smooth ER: Engaged in lipid synthesis and detoxification processes.
- Golgi Apparatus: Functions in modifying, sorting, and packaging proteins and lipids for secretion or delivery.
- Lysosomes: Contain digestive enzymes for breaking down waste materials.
- Chloroplasts: Found in plant cells; sites of photosynthesis, converting solar energy to glucose.

Genetics

DNA Structure: Comprises a double helix formed by nucleotides with bases adenine (A), thymine (T), cytosine (C), and guanine (G).
Gene: Defined as a DNA segment coding for specific proteins or observable traits.
Alleles: Variants of a gene that can lead to different traits.
Mendelian Inheritance:
- Involves dominant and recessive traits influencing observable characteristics.
- Law of Segregation states alleles segregate during gamete (sex cell) formation.
- Law of Independent Assortment indicates genes for different traits are inherited independently.

Evolution

Natural Selection: A central mechanism driving evolution; organisms that are better adapted to their environments tend to survive and reproduce.
Common Descent: Theory that all living organisms originated from a shared ancestor.
Speciation: The evolutionary process resulting in the formation of new species.

Ecology

Ecosystem: A system formed by the interaction of living organisms with their physical environment.
Biomes: Major ecological regions, such as tundras and rainforests, characterized by specific climates and vegetation types.
Food Chains/Webs: Represent energy flow; begins with producers (autotrophs), followed by consumers (heterotrophs), and ending with decomposers.
Biodiversity: The wide variety of life forms in an ecosystem; crucial for resilience and adaptability.

Human Biology

Organ Systems: Comprised of multiple systems including circulatory, respiratory, digestive, nervous, muscular, skeletal, immune, endocrine, reproductive, integumentary, and urinary systems.
Homeostasis: The process that maintains stable internal conditions (like temperature and pH) necessary for survival.
Metabolism: Refers to all biochemical reactions that sustain life, categorized into catabolic (breaking down molecules) and anabolic (building up molecules).

Microbiology

Bacteria: Prokaryotic microorganisms categorized by shape (cocci, bacilli, spirilla).
Viruses: Non-cellular entities that depend on host cells to replicate and carry out life cycles.
Fungi: Eukaryotic organisms acting primarily as decomposers, important for nutrient recycling and biotechnology.

Plant Biology

Photosynthesis: The biochemical process by which plants convert light energy into chemical glucose energy.
Plant Structure:
- Roots: Function in absorption of water and nutrients from soil.
- Stems: Provide structural support and facilitate the transport of nutrients and water.
- Leaves: Major sites for photosynthesis, maximizing light absorption.
Reproduction:
- Asexual: Methods include cloning or budding.
- Sexual: Involves pollination and seed formation.

Animal Behavior

Innate Behavior: Automatic, instinctual actions encoded in genetics (e.g., reflexes).
Learned Behavior: Behaviors acquired through experience and interaction with the environment (e.g., classical conditioning).
Social Behavior: Interactions among individuals, covering cooperation, competition, and mating processes.

Biotechnology

Genetic Engineering: The process of altering an organism's DNA to achieve desired genetic traits.
CRISPR-Cas9: A cutting-edge technology that provides precise genetic editing capabilities.
Stem Cells: Undifferentiated cells with the potential to develop into various cell types, offering possibilities for regenerative medicine.