Introduction to Biology

• Biology is the scientific study of life, encompassing a range of topics from molecular mechanisms within cells to the interactions of organisms in ecosystems.
• Biology seeks to understand the characteristics, functions, and processes of living organisms.
• Biology explores the origin, evolution, and diversity of life on Earth.

Core Principles of Biology

• Cell theory states the cell is the basic unit of life.
• Gene theory states hereditary information is encoded in DNA and genes.
• Evolution describes how life evolves over time through processes like natural selection.
• Homeostasis defines how living organisms maintain a stable internal environment.

Levels of Biological Organization

• Atoms are the fundamental units of matter.
• Molecules are two or more atoms held together by chemical bonds, examples include DNA and proteins.
• Organelles are functional structures within cells, examples include the nucleus and mitochondria.
• Cells are the basic unit of life, examples include nerve cells and muscle cells.
• Tissues are groups of similar cells performing a specific function, examples include muscle tissue and nervous tissue.
• Organs are structures composed of different tissues working together, examples include the heart and brain.
• Organ Systems are groups of organs that cooperate to perform major bodily functions, examples include the digestive system and circulatory system.
• Organisms are individual living beings, examples include humans and plants.
• Populations are groups of individuals of the same species living in the same area.
• Communities are populations of different species living and interacting in the same area.
• Ecosystems are communities of organisms and their physical environment.
• Biosphere includes all ecosystems on Earth.

Cell Biology

• Cell Structure includes organelles like the nucleus (containing DNA), mitochondria (producing energy), ribosomes (synthesizing proteins), and the cell membrane (controlling what enters and exits the cell).
• Cell Function encompasses processes like cell division (mitosis and meiosis), cell signaling, and transport of molecules across membranes.
• Cell Types include eukaryotic cells (with a nucleus and membrane-bound organelles) and prokaryotic cells (without a nucleus or membrane-bound organelles).

Genetics

• DNA Structure is a double helix composed of nucleotides (adenine, guanine, cytosine, and thymine).
• Genes are segments of DNA that code for specific proteins.
• Chromosomes are structures made of DNA that contain genes.
• Gene Expression describes the process by which the information encoded in a gene is used to synthesize a functional gene product (protein).
• Mutation refers to changes in the DNA sequence that can lead to genetic variation.
• Inheritance is the term for transmission of genetic information from parents to offspring.
• Genetic engineering is modifying an organism's genes to transfer a characteristic or for research.

Evolution

• Natural Selection is the differential survival and reproduction of individuals based on heritable traits.
• Adaptation refers to inherited traits that enhance survival and reproduction in a specific environment.
• Speciation is the process by which new species arise.
• Evidence for Evolution comes from the fossil record, comparative anatomy, embryology, and molecular biology.
• Phylogeny is the evolutionary history and relationships among organisms.

Ecology

• Ecosystems are communities of organisms and their physical environment interacting as a functional unit.
• Energy Flow is the transfer of energy through trophic levels (producers, consumers, decomposers).
• Nutrient Cycling refers to the movement of essential elements (e.g., carbon, nitrogen) through ecosystems.
• Population Ecology is the study of population size, density, distribution, and dynamics.
• Community Ecology is the study of interactions between different species in a community (e.g., competition, predation, symbiosis).
• Conservation Biology includes efforts to protect and preserve biodiversity.

Plant Biology

• Photosynthesis describes the process by which plants convert light energy into chemical energy.
• Plant Structure includes roots, stems, leaves, flowers, and their functions.
• Plant Reproduction includes sexual and asexual reproduction in plants.
• Plant Physiology is the study of plant functions and processes.

Animal Biology

• Animal Structure refers to the Anatomy of different organ systems (e.g., circulatory, respiratory, nervous).
• Animal Physiology is the study of animal functions and processes.
• Animal Behavior describes how animals interact with their environment and each other.
• Animal Classification refers to the Taxonomy and phylogeny of different animal groups.

Microbiology

• Bacteria are Unicellular prokaryotic organisms.
• Viruses are Non-cellular entities that require a host to reproduce.
• Fungi are Eukaryotic organisms that include yeasts and molds.
• Protists are a diverse group of eukaryotic microorganisms.
• Microbial Ecology refers to the study of the interactions between microbes and their environment.
• Infectious Diseases are diseases caused by pathogenic microorganisms.

Anatomy and Physiology

• Anatomy is the study of the structure of the body.
• Physiology is the study of the function of the body's systems.
• Skeletal System provides support and structure.
• Muscular System enables movement.
• Nervous System controls and coordinates bodily functions.
• Endocrine System regulates hormones.
• Cardiovascular System transports blood, oxygen, and nutrients.
• Respiratory System facilitates gas exchange.
• Digestive System breaks down food for energy.
• Urinary System filters waste from the blood.
• Immune System defends against pathogens.
• Reproductive System enables reproduction.