Introduction to Biology

Introduction to Biology

• Biology is the study of life and living organisms, encompassing their structure, function, growth, origin, evolution, and distribution.
• It seeks to understand the interactions between organisms and their environment.
• Broad areas of study within biology include:
  • Cell biology
  • Genetics
  • Ecology
  • Evolution
  • Physiology
  • Microbiology
  • Botany
  • Zoology
• The scientific method is crucial for biological research and discovery.

Biological Molecules

• Four major classes of biological macromolecules are essential for life:
  • Carbohydrates: Provide energy and structural support. Examples include sugars (glucose, fructose) and starches.
  • Lipids: Store energy, form cell membranes, and act as hormones. Fatty acids, phospholipids, and steroids are examples.
  • Proteins: Perform diverse functions, including catalyzing reactions (enzymes), transporting molecules, and providing structural support. Amino acids are the building blocks.
  • Nucleic acids: Store and transmit genetic information. DNA and RNA are the primary examples.

Cells

• The cell is the basic unit of life.
• Prokaryotic cells lack a nucleus and membrane-bound organelles. Bacteria are an example.
• Eukaryotic cells have a nucleus and membrane-bound organelles, enabling compartmentalization of functions. Animal and plant cells are examples.
• Cellular processes include:
  • Respiration: Breakdown of molecules to release energy.
  • Photosynthesis: Conversion of light energy into chemical energy.
  • Mitosis: Cell division for growth and repair.
  • Meiosis: Cell division for sexual reproduction.

Genetics

• Genetics is the study of heredity and variation in organisms.
• DNA is the molecule that carries genetic information.
• Genes are segments of DNA that code for specific proteins.
• Inheritance patterns are determined by the principles of Mendelian genetics.
• Genetic mutations can lead to variations and sometimes diseases.
• Modern genetics includes areas like:
  • Genomics
  • Proteomics
  • Bioinformatics

Evolution

• Evolution is the change in heritable characteristics of biological populations over successive generations.
• Natural selection is a key mechanism of evolution, favoring traits that enhance survival and reproduction.
• Evidence for evolution includes the fossil record, comparative anatomy, and molecular biology.
• Adaptation is the process by which organisms become better suited to their environments through evolutionary changes.

Ecology

• Ecology is the study of the relationships between organisms and their environment.
• Key ecological concepts include:
  • Ecosystems: Communities of organisms interacting with their physical environment.
  • Populations: Groups of individuals of the same species interacting in a particular area.
  • Communities: Assemblages of different populations interacting in an area.
  • Biomes: Large-scale ecosystems characterized by specific climate and vegetation.
  • Biodiversity: The variety of life on Earth at all levels, from genes to ecosystems.

Physiology

• Physiology investigates the functions of organisms and their parts.
• Examples include:
  • Biological processes in different organ systems: digestive, respiratory, circulatory
  • Body’s response to internal and external stimuli.
  • Hormonal regulation and neurotransmission.
  • Homeostasis: Maintaining a stable internal environment.

Microbiology

• Microbiology is the study of microscopic organisms, including:
  • Bacteria
  • Viruses
  • Fungi
  • Protists
• Includes their structure, function, and interactions with other organisms.
• Microorganisms are important in diverse processes, including:
  • Decomposition and nutrient cycling
  • Industrial applications (fermentation)
  • Disease causation and treatment

Botany

• Botany is the study of plants.
• It encompasses various aspects of plant life, including morphology, physiology, genetics, evolution, and ecology.
• Plant diversity and organization is a key subject.

Zoology

• Zoology is the study of animals.
• It includes the study of animal diversity, anatomy, physiology, behavior, evolution, and ecology.
• Different approaches, including comparative anatomy and behavioral studies.