Introduction to Biology

Biology is the scientific study of life and living organisms.
It encompasses various fields that explore the structure, function, growth, evolution, and distribution of living organisms.

Cell Biology
- Study of cells, their physiological properties, structure, organelles, interactions, and behavior.
Genetics
- Focuses on heredity, genetic variation, and the molecular basis of genes.
Evolutionary Biology
- Examines the origins and changes in species over time through processes such as natural selection and speciation.
Ecology
- Studies interactions between organisms and their environment, including ecosystems and biodiversity.
Physiology
- Investigates the functions and processes of living organisms and their parts.
Botany
- The study of plants, including their structure, properties, and biochemical processes.
Zoology
- Focuses on animals, their behavior, physiology, classification, and distribution.

Cell Theory
- All living organisms are composed of cells.
- The cell is the basic unit of life.
- All cells arise from pre-existing cells.
DNA and Genetics
- DNA carries genetic information necessary for growth, development, and reproduction.
- Genes are segments of DNA that code for proteins.
Homeostasis
- The ability of an organism to maintain stable internal conditions despite external changes.
Natural Selection
- Mechanism of evolution where organisms better adapted to their environment tend to survive and reproduce.

Molecular Level
- Atoms and molecules, including proteins, lipids, carbohydrates, and nucleic acids.
Cellular Level
- The smallest unit of life; encompasses prokaryotic (bacteria) and eukaryotic (plants, animals, fungi) cells.
Tissue Level
- Groups of similar cells working together (e.g., epithelial, connective, muscle, and nervous tissues).
Organ Level
- Structures composed of different tissues performing a specific function (e.g., heart, lungs).
Organ System Level
- Groups of organs working together (e.g., circulatory system, respiratory system).
Organism Level
- Individual living entities.
Population Level
- Groups of individuals of the same species living in a defined area.
Community Level
- Different species interacting in a shared environment.
Ecosystem Level
- Interactions between communities and their physical environment.
Biosphere Level
- The global sum of all ecosystems; the zone of life on Earth.

Understanding biological processes is crucial for fields such as medicine, environmental science, biotechnology, and agriculture.
Aids in addressing global challenges like disease, food security, and climate change.

Biology studies life and living organisms across various fields such as structure, function, growth, evolution, and distribution.

Cell Biology: Examines the properties, structure, organelles, and interactions of cells.
Genetics: Investigates heredity and genetic variation, focusing on the molecular basis of genes.
Evolutionary Biology: Explores origins and adaptations of species over time via natural selection and speciation processes.
Ecology: Analyzes interactions among organisms and their environments, emphasizing ecosystems and biodiversity.
Physiology: Studies the functions and processes that occur within living organisms.
Botany: Focuses on plants, covering their structure, properties, and biochemical processes.
Zoology: Examines animals, including their behavior, physiology, classification, and geographical distribution.

Cell Theory:
- All living organisms consist of cells.
- The cell is the fundamental unit of life.
- New cells originate from existing cells.
DNA and Genetics:
- DNA is the carrier of genetic information critical for development and reproduction.
- Genes are DNA segments coding for proteins.
Homeostasis:
- The capability of organisms to maintain stable internal conditions despite external changes.
Natural Selection:
- An evolutionary mechanism where organisms better suited to their environment are more likely to survive and reproduce.

Molecular Level: Composed of atoms and molecules like proteins, lipids, carbohydrates, and nucleic acids.
Cellular Level: The smallest life unit, including prokaryotic (bacteria) and eukaryotic (plants, animals, fungi) cells.
Tissue Level: Groups of similar cells functioning together (e.g., epithelial, connective, muscle, nervous tissues).
Organ Level: Structures made of different tissues that accomplish specific functions (e.g., the heart and lungs).
Organ System Level: Groups of organs collaborating (e.g., circulatory system, respiratory system).
Organism Level: Individual living entities.
Population Level: Groups of individuals of the same species in a specific area.
Community Level: Multiple species interacting within a shared environment.
Ecosystem Level: The interaction of communities with their physical surroundings.
Biosphere Level: Represents the global collection of all ecosystems, the Earth’s life zone.

Essential for fields like medicine, environmental science, biotechnology, and agriculture.
Contributes to solving global issues related to health, food supply, and environmental change.