Biology Core Concepts - Life Chapter 1

Definition of Biology

• Biology is the natural science that studies life and living organisms, encompassing their structure, function, development, interactions, evolution, distribution, and taxonomy.

Relationship with Other Disciplines

• Biology interrelates with various scientific fields, enhancing understanding and collaborative research.

Levels of Study in Biology

• Biology can be examined on multiple hierarchical levels, from atoms to entire ecosystems, reflecting the complexity of life.

Existence of Life on Earth

• Life thrives in diverse environments, from polar regions to equatorial zones, indicating its adaptability.

Size Range of Organisms

• Organisms vary drastically in size, from microscopic single-celled algae to towering trees measuring over 115 meters.

Hierarchical Organization in Biology

• Biological organization ranges from small-scale atomic levels to large-scale biospheric levels:
  • Atoms
  • Molecules
  • Cells
  • Tissues
  • Organs
  • Organ Systems
  • Organisms
  • Populations
  • Communities
  • Biosphere

Emergent Properties

• Each level of biological organization exhibits unique emergent properties not present in the constituent parts, emphasizing the concept of complexity.

Atomic Level

• Atoms represent the foundational level of biology; the arrangement and types of atoms affect biological structure and function.
• Six essential elements constitute about 99% of the human body's composition:
  • Oxygen (65%)
  • Carbon (18%)
  • Hydrogen (10%)
  • Nitrogen (3%)
  • Calcium (1.5%)
  • Phosphorus (1.0%)

Molecular Level

• Molecules, formed from bonded atoms, are vital for biological functions, including proteins, carbohydrates, lipids, nucleic acids, hormones, and enzymes.

Cellular Level

• Cells are recognized as the basic units of life; organisms can be unicellular (e.g., Amoeba, Euglena).

Tissue Level

• Tissues consist of grouped cells working together for similar functions, such as muscle, blood, xylem, and epithelium.

Organ Level

• Organs are complex structures formed from various tissues, performing specific functions (e.g., photosynthesis in leaves, blood circulation by the heart).

Organ System Level

• Organ systems are groups of organs that cooperate to achieve common physiological goals (e.g., digestive, circulatory, and reproductive systems).

Organism Level

• An organism is a self-contained entity, which may be unicellular or composed of multiple cells organized into tissues and organs.

Population Level

• A population is a collection of organisms of the same species residing in a specific geographical area and capable of interbreeding.

Community Level

• A community includes multiple populations of different species interacting within a shared environment, forming a complex biological network.

Explore the fundamental concepts of biology in this quiz, focusing on the study of life and living organisms. Understand how biology encompasses structure, function, and evolution as outlined in lectures 7 and 8. Test your knowledge on the properties and categories defining biological sciences.