Regents Biology Review: Key Ideas 1-3

Introduction

• Purpose: Review essential biology content for the Regents Living Environment Exam in NY or as a general biology refresher.
• Exam Format: Mix of multiple choice, open-ended questions, lab skills, and scientific inquiry.
• Focus: Biology knowledge and content, not laboratory skills.

Levels of Organization in Life

• Key Concept: Life is organized, one characteristic of life.
• Population: Group of organisms of one species in one location.
• Food Web: Shows interconnectedness of food chains in an ecosystem.
  • Trophic Levels: Producers, consumers, decomposers.
  • Autotrophs (Producers): Make their own food (e.g., plants).
  • Heterotrophs (Consumers): Consume other organisms.
• Trophic Pyramid: Energy loss at each level, efficient to consume lower on the pyramid.

Ecosystems

• Biotic and Abiotic Factors: Shape ecosystems through interactions.
• Carrying Capacity: Maximum population an environment can sustain due to limited resources.
• Human Complexity: Molecules → Cells → Tissues → Organs → Organ Systems.

Homeostasis

• Definition: Maintaining stable internal balance; failure leads to disease or death.
• Examples: Sweating to cool down, shivering to generate heat.

Cells and Organelles

• Specialized Structures: Organelles have specific functions.
  • Mitochondria: Energy production.
  • Ribosomes: Protein synthesis.
  • Nucleus: DNA storage.
  • Chloroplasts: Photosynthesis (in plant cells).
• Cell Communication: Receptor molecules receive signals for interaction.

DNA and Genetics

• Genes: Sections of DNA coding for proteins.
  • DNA Structure: Double helix, nucleotides with complementary base pairs (A-T, G-C).
• Protein Synthesis: DNA → mRNA → Protein (transcription and translation).

Genetic Engineering and Biotechnology

• Artificial Selection: Selective breeding of plants and animals.
• Genetic Engineering: Manipulating genes using gel electrophoresis.
• Phylogenetic Trees/Cladograms: Show evolutionary relationships.

Evolution and Natural Selection

• Mutations and Variation: Random mutations lead to new traits.
  • Natural Selection: Adapted organisms survive and reproduce.
• Adaptations: Behavioral, structural, reproductive; enhance survival.
• Evolution Over Time: Change in allele frequencies; populations evolve, not individuals.
• Extinction: Occurs when species cannot adapt to environmental changes.

Conclusion

• Review: Key Ideas 1-3 of biology curriculum.
• Next Steps: Stay tuned for the next video in the series.
• Study Tip: Review provided resources and practice with exam questions.