Regents Biology Review - Key Ideas 1-3

Jun 14, 2024

Regents Biology Review - Key Ideas 1-3

Introduction

  • Regents Biology Review series to help students with the Regents Living Environment Exam (New York State).
  • Can be used for general biology refreshers or other states' exam reviews.
  • Regents exam: Four-part, includes multiple choice, open-ended questions, and lab skills.
  • This video covers specific biology knowledge and content, focusing on key ideas 1-3.

Levels of Organization and Characteristics of Life

  • Levels of Organization in Life:

    • Population: Group of organisms of one species in one location.
    • Trophic levels: Producers (autotrophs), Consumers (heterotrophs), Decomposers.
    • Food Chains vs. Food Webs: Food chain shows one pathway, food web shows interconnected pathways.
    • Autotrophs (Producers): Make their own food (e.g., plants).
    • Heterotrophs (Consumers): Consume other organisms for food.
  • Trophic Pyramid:

    • Energy transfer between levels, significant loss (90%) of energy with each level.
    • More efficient to consume lower on the pyramid.
  • Ecosystem Factors:

    • Biotic (living) and abiotic (non-living) factors interaction.
    • Competition and interaction maintain stability.
    • Carrying Capacity: Maximum population an environment can sustain.
    • Human Impact: Complex interactions within human bodies; levels of cells, tissues, organs, systems maintaining homeostasis.

Homeostasis and Cell Structures

  • Homeostasis: Maintaining stable internal conditions (e.g., human sweating to cool down).

  • Cell Specialization:

    • Organelle functions: Mitochondria (energy), Ribosomes (protein synthesis), Nucleus (DNA storage), Vacuole (storage), Cell Membrane (selective barrier), Cell Wall (support in plants), Chloroplast (photosynthesis).
    • Differences between Eukaryotic and Prokaryotic cells:
      • Eukaryotic: Complex, membrane-bound organelles, DNA in nucleus.
      • Prokaryotic: Simpler, no membrane-bound organelles, DNA not enclosed, e.g., bacteria.
  • Cell Communication:

    • Signaling pathways, hormone/receptor interactions.
    • Disruption affects cell/organism stability (e.g., caffeine blocks adenosine).

Genetics and Biotechnology

  • Genes and Environment:

    • Gene expression can be modified by the environment (e.g., identical twins in different environments).
    • Traits often influenced by multiple genes.
  • DNA Structure and Function:

    • DNA: Nucleic acid, composed of nucleotides (phosphate, sugar, base).
    • Base Pairing: A-T, G-C; double helix structure.
    • Genes code for proteins, different expression in different cells.
  • Protein Synthesis:

    • Transcription (DNA to mRNA) and Translation (mRNA to protein).
    • Universal genetic code shared by all organisms.
  • Genetic Engineering & Biotechnology:

    • Selective Breeding: Artificial selection for desired traits.
    • Genetic Engineering: Manipulating genes (e.g., Bt corn, modified bacteria).
    • Gel Electrophoresis: DNA fingerprinting for analysis, paternity testing, studying evolutionary relationships.

Evolution

  • Evolutionary Processes:

    • Species evolve from earlier distinct species via gene mutations and inheritance.
    • Adaptation to environments via natural selection (e.g., antibiotic-resistant bacteria).
  • Phylogenetic Trees (Cladograms):

    • Diagrams showing evolutionary relationships, common ancestors.
    • Traits appearing on branches show relatedness.
    • Populations evolve, individuals don't.
  • Extinction and Fossil Record:

    • Environmental changes can lead to species extinction.
    • Most species that have existed are extinct, evidenced by fossil record.

Conclusion

  • Stay tuned for further parts in the video series.
  • Good luck with exam preparation.