Introduction to Biology

Introduction to Biology

• Definition: The study of life and living organisms, encompassing their structure, function, growth, evolution, distribution, and taxonomy.

Branches of Biology

1. Cell Biology: Study of cell structure, function, and processes.
2. Molecular Biology: Focuses on the biochemical processes within cells.
3. Genetics: Study of heredity and variation in organisms.
4. Evolutionary Biology: Examines the origins and changes in biodiversity over time.
5. Ecology: Study of organisms and their interactions with the environment.
6. Botany: Study of plants.
7. Zoology: Study of animals.

Fundamental Concepts

• Cell Theory:

  • All living things are made up of cells.
  • The cell is the basic unit of life.
  • All cells arise from pre-existing cells.

• Theory of Evolution:

  • Proposed by Charles Darwin.
  • Explains how species change over time through natural selection.

• Genetic Information:

  • DNA (deoxyribonucleic acid) carries genetic information.
  • Genes are segments of DNA that determine traits.

Biological Classification (Taxonomy)

• Levels of Classification:
  1. Domain
  2. Kingdom
  3. Phylum
  4. Class
  5. Order
  6. Family
  7. Genus
  8. Species

Homeostasis

• Maintenance of a stable internal environment in response to external changes.

Photosynthesis and Cellular Respiration

• Photosynthesis: Process by which green plants convert light energy into chemical energy (glucose) using chlorophyll.

  • Equation: 6 CO₂ + 6 H₂O + light energy → C₆H₁₂O₆ + 6 O₂

• Cellular Respiration: Process by which cells convert glucose into ATP (energy) using oxygen.

  • Equation: C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O + ATP

Roles of Proteins

• Structural components of cells (e.g., collagen).
• Enzymes that catalyze biochemical reactions.
• Hormones that regulate physiological processes.

Importance of Biodiversity

• Enhances ecosystem productivity and resilience.
• Provides resources for food, medicine, and new technologies.

Scientific Method

1. Observation
2. Question
3. Hypothesis
4. Experimentation
5. Analysis
6. Conclusion

Key Organisms and Systems

• Prokaryotic Cells: Simple, single-celled organisms without a nucleus (e.g., bacteria).
• Eukaryotic Cells: More complex cells with a nucleus (e.g., plants, animals, fungi).

Conclusion

• Biology is an expansive field that addresses essential questions about life, integrating work across various sub-disciplines to understand living systems and their interactions.

Introduction to Biology

• Biology is the study of life and living organisms, encompassing their structure, function, growth, evolution, distribution, and taxonomy.

Branches of Biology

• Cell Biology: Focuses on the structure, function, and processes within cells.
• Molecular Biology: Examines the biochemical reactions within cells.
• Genetics: Studies heredity and variation in organisms.
• Evolutionary Biology: Investigates the origin and changes of biodiversity over time.
• Ecology: Studies the interactions between organisms and their environment.
• Botany: Focuses on the study of plants.
• Zoology: Studies animals.

Fundamental Concepts

• Cell Theory: All living organisms are composed of cells, the basic unit of life; cells arise from pre-existing cells.
• Theory of Evolution: Proposed by Charles Darwin, it explains how species change over time through natural selection.
• Genetic Information: DNA (deoxyribonucleic acid) carries genetic information; genes, segments of DNA, determine traits.

Biological Classification (Taxonomy)

• Levels of Classification: Domains, Kingdoms, Phyla, Classes, Orders, Families, Genera, and Species.

Homeostasis

• Living organisms maintain a stable internal environment despite external changes.

Photosynthesis and Cellular Respiration

• Photosynthesis: Green plants convert light energy into chemical energy (glucose) using chlorophyll. Equation: 6 CO₂ + 6 H₂O + light energy → C₆H₁₂O₆ + 6 O₂

• Cellular Respiration: Cells convert glucose into ATP (energy) using oxygen. Equation: C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O + ATP

Roles of Proteins

• Proteins are structural components of cells (e.g., collagen), enzymes that catalyze biochemical reactions, and hormones that regulate physiological processes.

Importance of Biodiversity

• Biodiversity enhances ecosystem productivity, resilience, and provides resources for food, medicine, and new technologies.

Scientific Method

• Steps: Observation, Question, Hypothesis, Experimentation, Analysis, Conclusion.

Key Organisms and Systems

• Prokaryotic Cells: Simple, single-celled organisms without a nucleus (e.g., bacteria).
• Eukaryotic Cells: More complex cells with a nucleus (e.g., plants, animals, fungi).

Conclusion

• Biology is a vast field that investigates life and its systems, integrating various sub-disciplines to understand living organisms.