Core Principles of Biology

• Biology is the scientific study of life.

Core Principles of Biology

• Biology explores the structure, function, growth, origin, evolution, distribution, and taxonomy of living organisms.
• Central to biology are the concepts of cell theory, gene theory, evolution, homeostasis, and thermodynamics.

Cell Theory

• The cell theory states that all living organisms are composed of cells.
• The cell is the basic unit of structure and function in living organisms.
• All cells arise from pre-existing cells.

Gene Theory

• Gene theory is the idea that characteristics of living organisms are passed from parents to their offspring via genes.
• Genes are located on chromosomes and consist of DNA.
• Genes encode specific traits and characteristics.

Evolution

• Evolution is the change in heritable characteristics of biological populations over successive generations.
• Natural selection is a key mechanism of evolution, leading to adaptation.
• Evolutionary biology studies the processes of evolution and the relationships between different organisms.

Homeostasis

• Homeostasis is the ability of an organism or environment to maintain stability in spite of changes.
• It involves maintaining a stable internal environment, including temperature, pH, and solute concentrations.
• Feedback mechanisms regulate homeostasis.

Thermodynamics

• Thermodynamics governs the energy flow and transformations in living organisms.
• Organisms obtain and use energy to perform life processes.
• Metabolic processes involve energy transfer and conversions.

Biological Organization

• Life is organized in a hierarchy from atoms and molecules to cells, tissues, organs, organ systems, organisms, populations, communities, ecosystems, and the biosphere.
• Each level of organization builds upon the previous one, with emergent properties arising at each level.

Branches of Biology

• Biochemistry studies the chemical processes within and relating to living organisms.
• Molecular biology examines the molecular basis of biological activity.
• Botany is the scientific study of plants.
• Zoology studies animals, including their structure, physiology, development, and classification.
• Microbiology is the study of microorganisms, including bacteria, viruses, and fungi.
• Ecology studies the interactions between organisms and their environment.
• Genetics is the study of heredity and variation in organisms.

Scientific Method in Biology

• Biology relies on the scientific method for inquiry and discovery.
• The scientific method involves observation, hypothesis formation, experimentation, data analysis, and conclusion.
• Hypotheses are testable explanations for observed phenomena.
• Experiments are designed to test hypotheses and gather evidence.

Diversity of Life

• Life on Earth is incredibly diverse, encompassing a wide range of organisms and ecosystems.
• Biodiversity refers to the variety of life at all its levels, from genes to ecosystems.
• Classification systems, such as taxonomy, are used to organize and categorize living organisms.

Genetics and Heredity

• Genetics studies genes, heredity, and variation in living organisms.
• DNA (deoxyribonucleic acid) is the hereditary material in most organisms.
• Genes are segments of DNA that encode specific traits.
• Heredity is the passing of traits from parents to offspring.
• Genetic variation arises through mutation, recombination, and other processes.

Cell Structure and Function

• Cells are the basic structural and functional units of life.
• Eukaryotic cells have a nucleus and other membrane-bound organelles; prokaryotic cells do not.
• Organelles perform specific functions within the cell.
• The cell membrane controls the movement of substances into and out of the cell.

Metabolism

• Metabolism refers to all the chemical processes that occur within a living organism.
• Catabolism involves the breakdown of complex molecules into simpler ones, releasing energy.
• Anabolism involves the synthesis of complex molecules from simpler ones, requiring energy.
• Enzymes are biological catalysts that speed up metabolic reactions.

Evolution and Natural Selection

• Evolution is the change in the heritable characteristics of biological populations over successive generations.
• Natural selection is a key mechanism of evolution, leading to adaptation.
• Variation exists within populations, and individuals with advantageous traits are more likely to survive and reproduce.
• Over time, natural selection can lead to the evolution of new species.

Ecology and Ecosystems

• Ecology studies the interactions between organisms and their environment.
• Ecosystems consist of communities of organisms interacting with each other and their physical environment.
• Energy flows through ecosystems via food chains and food webs.
• Nutrient cycles, such as the carbon and nitrogen cycles, are essential for maintaining life in ecosystems.

Plant Biology

• Plant biology studies the structure, function, growth, and classification of plants.
• Plants are autotrophs, meaning they produce their own food through photosynthesis.
• Plant cells have unique structures, such as cell walls and chloroplasts.
• Plants play crucial roles in ecosystems, including producing oxygen and providing food and habitat for other organisms.

Animal Biology

• Animal biology studies the structure, function, behavior, and evolution of animals.
• Animals are heterotrophs, meaning they obtain their food from other organisms.
• Animals have diverse body plans and adaptations for survival in different environments.
• Animal behavior is influenced by both genetics and environment.

Microbiology

• Microbiology is the study of microorganisms like bacteria, archaea, fungi, protists, and viruses.
• Microorganisms play important roles in nutrient cycling, decomposition, and disease.
• Some microorganisms are beneficial, while others are pathogenic.
• Microbiology has applications in medicine, agriculture, and industry.

Human Biology

• Human biology studies the structure, function, growth, evolution, and behavior of the human body
• Humans are complex organisms with organ systems that work together to maintain homeostasis
• Human health is influenced by genetics, environment, and lifestyle factors
• Human biology is relevant to medicine, public health, and other fields.

Conservation Biology

• Conservation biology seeks to protect and manage biodiversity.
• Threats to biodiversity include habitat loss, climate change, pollution, and invasive species.
• Conservation strategies include habitat restoration, species management, and protected areas.
• Conservation biology aims to ensure the long-term survival of species and ecosystems.

Biotechnology

• Biotechnology uses biological systems, living organisms, or derivatives to develop or create different products
• Modern biotechnology is often associated with the use of genetically engineered microorganisms
• New technologies and products are developed by biotechnology to treat diseases, produce new materials, etc.
• Biotechnology has applications in medicine, agriculture, and industry.

Biology explores life's structure, function, and evolution, emphasizing cell theory, gene theory, and thermodynamics. Cell theory states that all organisms are composed of cells, the basic units of life. Gene theory explains trait inheritance through DNA-encoded genes on chromosomes.