Biology Video Recap

Introduction

• Discussion on summarizing biology videos for a recap video
• Importance of scientific names over common names

Characteristics of Life

• Challenges in defining life
• Comparison of bathtub pony vs. real pony
• Key characteristics of life (e.g., made of cells, growth, reproduction, response to stimuli)

Biological Levels of Organization

• Cell theory: smallest living unit, all living things made of cells, cells come from pre-existing cells
• Hierarchy: cells -> tissues -> organs -> organ systems -> organism -> population -> community -> ecosystem -> biome -> biosphere

Biomolecules

• Four major macromolecules: carbohydrates, lipids, proteins, nucleic acids
• Building blocks: monosaccharides, fatty acids & glycerol, amino acids, nucleotides
• Functions of biomolecules (e.g., energy storage, structural support, enzymatic activity)

Enzymes

• Enzyme structure: active site, substrate, products
• Importance in speeding up reactions; specific temperature and pH ranges
• Denaturation if outside ideal conditions

Cell Structure

• Differences between prokaryotic and eukaryotic cells
• Organelles: nucleus, endoplasmic reticulum, golgi apparatus, mitochondria
• Unique features of plant vs. animal cells

Cell Membrane

• Importance in homeostasis; controls entry and exit of substances
• Structure: phospholipid bilayer with polar heads and nonpolar tails
• Types of transport: passive (simple and facilitated diffusion), active transport
• Water transport: osmosis, aquaporins

Cell Respiration & Photosynthesis

• Cellular respiration: breakdown of glucose to yield ATP
• Photosynthesis: production of glucose using sunlight
• Relationship between cellular respiration and photosynthesis

DNA and Genetic Material

• DNA structure: nucleotides (phosphate, deoxyribose, nitrogenous base)
• Base pairing: adenine-thymine, cytosine-guanine
• Chromosomes: 46 in humans, 23 from each parent

DNA Replication

• Key enzymes: helicase, primase, DNA polymerase, ligase
• Process: unwinding, primer setting, strand building (5’ to 3’), Okazaki fragments on lagging strand

Cell Cycle

• Phases: G1 (growth), S (DNA synthesis), G2 (prepping for division), M (mitosis and cytokinesis)
• Checkpoints and regulation: proteins like Cdk, cyclin, p53
• Cancer: uncontrolled cell division

Mitosis and Meiosis

• Mitosis: produces identical body cells; stages (PMAT)
• Meiosis: produces gametes (sperm and egg), haploid cells
• Differences between mitosis and meiosis
• Crossing over during prophase I

Genetics

• Alleles: dominant (T), recessive (t), homozygous dominant (TT), heterozygous (Tt), homozygous recessive (tt)
• Punnett squares for monohybrid and dihybrid crosses
• Non-Mendelian genetics: incomplete dominance, codominance, sex-linked traits, multiple alleles
• Pedigrees: tracking traits

Protein Synthesis

• Steps: transcription (makes mRNA), translation (makes polypeptides)
• tRNA, rRNA, codon-anticodon relationships
• Effects of mutations: substitution, deletion, insertion, frameshift mutations

Evolution

• Natural selection: traits that enhance fitness become more common
• Genetic drift: random events influencing allele frequencies; bottleneck and founder effects
• Antibiotic resistance in bacteria

Bacteria and Viruses

• Bacteria: prokaryotic, helpful roles (e.g., digestion, nitrogen fixation)
• Viruses: non-living, need host to reproduce, not responsive to antibiotics
• Virus reproduction: lytic and lysogenic cycles

Classification of Life

• Domains: Bacteria, Archaea, Eukarya
• Taxonomy levels: Kingdom, Phylum, Class, Order, Family, Genus, Species

Plants

• Structure: vascular (xylem, phloem), nonvascular
• Photosynthesis: role of chloroplasts
• Reproduction: sexual (pollination, fertilization), asexual
• Important plant parts: stomata, guard cells

Ecosystems

• Food chains and webs: producers, consumers (primary, secondary, tertiary)
• Energy pyramid and 10% energy transfer rule
• Ecological succession: primary (new area, pioneer species), secondary (disturbance, soil present)

Biogeochemical Cycles

• Carbon cycle: photosynthesis, cellular respiration, fossil fuels
• Nitrogen cycle: nitrogen fixation, nitrification, assimilation, ammonification, denitrification

Ecological Relationships

• Predation, competition, symbiosis (commensalism, parasitism, mutualism)

Human Body Systems

• Overview of eleven body systems
• Importance of system interactions and coordination
• Example: adrenaline rush involving multiple systems

Conclusion

• Importance of understanding connections in biology
• Encouragement to explore topics further for deeper understanding