Key Concepts in Biology

Key Concepts in Biology

1. Cell Theory

• All living organisms are composed of cells.
• The cell is the basic unit of life.
• All cells arise from pre-existing cells.

2. Classification of Living Organisms

• Domains: Bacteria, Archaea, Eukarya
• Kingdoms: Animalia, Plantae, Fungi, Protista
• Hierarchical classification: Domain > Kingdom > Phylum > Class > Order > Family > Genus > Species

3. Genetics

• DNA Structure: Double helix composed of nucleotides (A, T, C, G).
• Gene: A segment of DNA that codes for a protein.
• Mendelian Genetics: Principles of inheritance (dominant/recessive traits).

4. Evolution

• Natural Selection: Survival of the fittest; organisms better adapted to their environment tend to survive and reproduce.
• Speciation: Formation of new species due to evolutionary processes.

5. Ecosystems and Biodiversity

• Ecosystem: A community of living organisms interacting with their environment.
• Biodiversity: Variety of life in a particular habitat or ecosystem.
• Importance of biodiversity for ecosystem resilience and human survival.

6. Photosynthesis and Cellular Respiration

• Photosynthesis: Process by which plants convert light energy into chemical energy (glucose).
  • Equation: 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂
• Cellular Respiration: Process of converting glucose into ATP.
  • Equation: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (ATP)

7. Human Biology

• Major systems: Circulatory, respiratory, digestive, nervous, and immune systems.
• Homeostasis: The maintenance of stable internal conditions in living organisms.

8. Microbiology

• Study of microorganisms: bacteria, viruses, fungi, and protozoa.
• Importance in health, disease, and environmental processes.

9. Ecology

• Study of interactions between organisms and their environment.
• Key concepts: food chains, food webs, energy flow, and nutrient cycles.

10. Plant Biology

• Structures: Roots, stems, leaves, flowers.
• Processes: Growth, reproduction, and responses to environmental stimuli.

Important Terms

• Homeostasis: Regulation of internal conditions.
• Metabolism: All biochemical processes in living organisms.
• Symbiosis: Interaction between two different organisms living in close physical proximity.

Key Figures

• Charles Darwin: Developed the theory of natural selection.
• Gregor Mendel: Father of modern genetics.

These notes provide a concise overview of fundamental concepts in biology, focusing on the essential principles and terminology required for a foundational understanding of the subject.

Key Concepts in Biology

Cell Theory

• All living organisms consist of cells, which serve as the fundamental unit of life.
• New cells are produced from the division of existing cells.

Classification of Living Organisms

• Organisms are divided into three domains: Bacteria, Archaea, and Eukarya.
• The kingdoms within these domains are Animalia, Plantae, Fungi, and Protista.
• Classification hierarchy goes from domain to species: Domain > Kingdom > Phylum > Class > Order > Family > Genus > Species.

Genetics

• DNA has a double helix structure made of nucleotides: adenine (A), thymine (T), cytosine (C), and guanine (G).
• Genes are specific DNA segments that code for proteins, influencing traits.
• Mendelian genetics details inheritance principles, notably dominant and recessive traits.

Evolution

• Natural selection describes how organisms best adapted to their environment have increased survival and reproduction rates.
• Speciation refers to the development of new species through evolutionary changes.

Ecosystems and Biodiversity

• An ecosystem includes all living organisms and their interactions within an environment.
• Biodiversity measures the variety of life within a specific ecosystem, crucial for resilience and human survival.

Photosynthesis and Cellular Respiration

• Photosynthesis is how plants transform light energy into chemical energy (glucose), represented by the equation: 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂.
• Cellular respiration converts glucose into ATP, following the equation: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (ATP).

Human Biology

• Key systems in human biology include the circulatory, respiratory, digestive, nervous, and immune systems.
• Homeostasis involves maintaining stable internal conditions essential for survival.

Microbiology

• Microbiology focuses on microorganisms, including bacteria, viruses, fungi, and protozoa, and their roles in health and environmental processes.

Ecology

• Ecology studies the interactions between organisms and their environment, encompassing food chains, food webs, energy flow, and nutrient cycles.

Plant Biology

• Plant structures consist of roots, stems, leaves, and flowers.
• Key processes include growth, reproduction, and reactions to environmental changes.

Important Terms

• Homeostasis: The regulation of stable internal environments in organisms.
• Metabolism: Encompasses all biochemical processes that occur within living organisms.
• Symbiosis: A close physical interaction between two different organisms, which can be beneficial, neutral, or harmful.

Key Figures

• Charles Darwin: Originated the theory of natural selection, explaining evolution.
• Gregor Mendel: Recognized as the father of modern genetics for his pioneering work on hereditary patterns.

This quiz covers essential principles in biology, including cell theory, genetics, evolution, and ecosystems. Test your understanding of how living organisms are classified, how genetic information is inherited, and the process of natural selection. Perfect for students looking to reinforce their biological knowledge.