Ultimate Biology Review

Intro

• Reviewing all of biology in less than 90 mins
• Focused on most important points
• Topics covered: Cell, Reproduction, Embryogenesis, Nervous System, Endocrine System, Respiratory System, Cardiovascular System, Immune System, Digestive System, Homeostasis (Kidney & Skin), Musculoskeletal System, Genetics, Evolution

Cell Theory

• Prokaryotes vs Eukaryotes
  • Prokaryotes: No nucleus, naked circular DNA
  • Eukaryotes: True nucleus, membrane-bound organelles, linear DNA
• Fundamental Tenets
  • All living things are composed of cells
  • Basic unit of life
  • Cells arise from pre-existing cells
  • Genetic info in DNA

Cell Structure

• Cell Membrane
  • Phospholipid bilayer
  • Hydrophilic heads outward, hydrophobic tails inward
• Organelles
  • Nucleus: Control center, contains DNA
  • Mitochondria: Powerhouse, ATP production
  • Rough ER: Protein synthesis
  • Smooth ER: Lipid synthesis, detox
  • Golgi: Sorts and modifies proteins
  • Lysosome: Breaks down waste
  • Peroxisome: Fat breakdown
  • Cytoskeleton: Structure & transport

Reproduction

• Mitosis vs Meiosis
  • Mitosis: 2 identical diploid cells
  • Meiosis: 4 non-identical haploid cells
  • Phases: Prophase, Metaphase, Anaphase, Telophase
• Gametogenesis
  • Spermatogenesis: Sperm development
  • Oogenesis: Egg development, meiosis I arrest in Prophase I, meiosis II arrest in Metaphase II

Embryogenesis

• Fetal Circulation
  • Placenta: Nutrient & waste exchange
  • Unique features: Foramen ovale, ductus arteriosus, ductus venosus
• Development Stages
  • Fertilization: Formation of zygote
  • Cleavage: Division without growth
  • Blastulation: Formation of blastocyst
  • Gastrulation: Formation of primary germ layers
  • Neurulation: CNS from ectoderm

Nervous System

• Central vs Peripheral
  • CNS: Brain and spinal cord
  • PNS: Nerves and ganglia
• Neuron Structure
  • Cell body, dendrites, axon
  • Myelin sheath: Insulates axon, speeds conduction
• Action Potential
  • Resting: -70mV, K+ efflux
  • Depolarization: Na+ influx
  • Repolarization: K+ efflux
  • Hyperpolarization: Excess K+ efflux

Endocrine System

• Hormone Classes
  • Peptides: Insulin, GH
  • Steroids: Estrogen, testosterone
  • Amines: Epi, norepi
• Major Glands and Functions
  • Hypothalamus: Regulatory hormones
  • Pituitary: GH, TSH, ACTH
  • Thyroid: T3, T4
  • Adrenal: Cortisol, aldosterone
  • Pancreas: Insulin, glucagon

Respiratory System

• Anatomy
  • Conducting zone: Nose to bronchioles
  • Respiratory zone: Alveoli
• Gas Exchange
  • Oxygen and CO2 exchange in alveoli
  • Surfactant reduces surface tension
• Pulmonary Function Tests (PFTs)
  • Measures lung volumes and capacities

Cardiovascular System

• Heart Anatomy and Function
  • Four chambers, valves
  • Blood flow: systemic and pulmonary circuits
• Cardiac Cycle
  • Systole: Ventricular contraction
  • Diastole: Ventricular relaxation
  • Cardiac output: HR x SV

Immune System

• Innate vs Adaptive Immunity
  • Innate: Non-specific, first line
  • Adaptive: Specific, memory
• Cells
  • B-cells: Produce antibodies
  • T-cells: Cell-mediated immunity

Digestive System

• Process of Digestion
  • Ingestion, breakdown (mechanical & chemical), absorption
• GI Organs and Functions
  • Stomach: Acid secretion, digestion
  • Small intestine: Nutrient absorption
  • Large intestine: Water absorption

Homeostasis

• Kidney Function
  • Filtration, reabsorption, secretion, excretion
  • Nephron structure: Glomerulus, tubules
• Skin Function
  • Protection, thermoregulation
  • Layers: Epidermis, dermis

Musculoskeletal System

• Muscle Types
  • Skeletal: Voluntary, striated
  • Cardiac: Involuntary, striated
  • Smooth: Involuntary
• Bone Structure
  • Compact vs spongy
  • Osteoblasts vs osteoclasts

Genetics and Evolution

• Genetic Principles
  • Mendel's Laws
  • Punnett Squares
  • Genetic mutations: Point, chromosomal
• Evolution
  • Natural selection: Process driving evolution