MCAT Biology Section - Cells and Reproductive System PDF

**MCAT - Biology Section** **1. Cells** **[1.1. Cell Theory]** - All organisms are made out of cells - Cells are the basic functional unit of life - Cells come from pre-existing cells - Cells carry genetic info (DNA) **[1.2. Eukaryotic Cells]** - Nucleus - - - Mitochon...

**MCAT - Biology Section** **1. Cells** **[1.1. Cell Theory]** - All organisms are made out of cells - Cells are the basic functional unit of life - Cells come from pre-existing cells - Cells carry genetic info (DNA) **[1.2. Eukaryotic Cells]** - Nucleus - - - Mitochondria - - - - Lysosomes - - Endoplasmic reticulum - - - - - Golgi apparatus - - Peroxisomes - - - Cytoskeleton - - - - - - - - - Types of tissues - - - - - - - - - **[1.3. Prokaryotic Cells]** - Bacteria - - - - - - - - - - - - - - - - - - - - - Archaea (compared to bacteria) - - - - **[1.4. Viruses]** - Virions (nucleocapsid) - - - - - - - - - - - - - - - - - Viroids (small circular ssRNA w/ no capsid, affects plants except for Hep. D in humans) - Prions (misfolded proteins, α helices to β-pleated sheets → solubility ↓, degradation ↓) **2. Reproductive System** **[2.1. Cell Cycle]** - Interphase - - - - - - - - Mitosis (**[PMAT]**, somatic cells, diploid parent 2*n*, 4*c* → 2 diploid daughters 2*n*, 2*c*) - - - - - - - - - - - - Checkpoints (damaged cells → cancer) - - - - **[2.2. Meiosis]** - Meiosis I (sex cells, reductional division, diploid parent 2*n*, 4*c* → 2 haploid daughters 1*n*, 2*c*) - - - - - - - - - - Meiosis II (equational division similar to mitosis, form 4 haploid daughters 1*n*, 1*c*) **[2.3. Reproduction]** - Sex - - - - - - - - - Male anatomy: **[SEVE(N)]** **[UP]** - - - - - - - - - - - - - - - - - - Female anatomy - - - - - - - - - - - Sexual development - - - - - - - - - Menstrual cycle (menarche to menopause) - - - - - - - - - - - - Menopause (FSH/LH sensitivity ↓ → estrogen/progesterone ↓) - **[2.4. Early Development]** - Pregnancy - - - - - - - - Stages of development - - - - - - - - - - - - - - - - - - - - - - - Development mechanisms - - - - - - - - - - - - - - - Fetal circulation - - - - - - **[2.5. Gestation]** - 1st trimester: major organs develop, heartbeat, bones harden - 2nd trimester: fetus activity ↑, face forms - 3rd trimester: antibodies transfer, growth rate ↓, fetus activity ↓ - Birth - - - - **3. Nervous System** **[3.1. Nerve Cells]** - Neurons - - - - - - - - Neuroglia (supports neurons) - - - - - - - - **[3.2. Impulse Transmission]** - Resting potential (--70 mV): high \[K^+^\], low \[Na^+^\] inside cell, (--) inside cell, (+) outside cell - - Action potential - - - - - Synapse (presynaptic neuron → synaptic cleft → postsynaptic neuron) - - - **[3.3 Nervous System]** - Nerves (PNS): sensory, motor, mixed - Tracts (CNS): afferent, efferent, interneurons - Central nervous system (CNS): brain and spinal cord - - - - Peripheral nervous system (PNS) - - - - - - - - - - - - - **4. Endocrine System** **[4.1. Hormone Mechanisms]** - Glands → hormones → bloodstream → target receptors - Hormones (**tropic** → stimulate gland → produce/release hormone, **direct** → hormone to target) - - - - - - - - - - - - - - - - - **[4.2. Organs and Hormones]** - Hypothalamus - - - - - - Anterior pituitary (glandular): **[FLAT]** **[PEG]** - - - - - - - - Posterior pituitary (neural) - - - Thyroid - - - - Parathyroid - - - - Adrenal [cortex] ([cortico]steroids): "3 S's" ([s]ugar, [s]alt, [s]ex) - - - - - - - - Adrenal medulla (catecholamines) - - Pancreas: - - - - - Gonads - - Pineal gland - - GI tract - - Kidneys - - Heart - - Thymus: - **5. Respiratory System** **[5.1. Breathing]** - Air pathway - - - - - - Lungs (visceral pleura → intrapleural space → parietal pleura) attaches to chest wall - - - Ventilation - - - - - - - - - Spirometer: measure lung volumes **except** for TLC and RV - - - - - - **[5.2. Respiratory Functions]** - Gas exchange - - - pH balance - - - - - - **6. Cardiovascular System** **[6.1. Heart Anatomy and Functions]** - Heart - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - **[6.2. Blood]** - Composition (plasma 55%, cells 45%) - - - - - - - - - - - - - - Hematopoiesis - - - Blood groups - - - - - - - Blood pressure: measured w/ sphygmomanometer - - - - Starling forces: hydrostatic (pushes fluid out) vs oncotic pressure (solute pulls fluid in) - - - O~2~ transport (insoluble in water, needs carrier → 4 O~2~ per Hb) - - - - - - - - Coagulation/clotting - - - **7. Immune System** **[7.1. Immune Structure]** - Immunity types - - - - - - Anatomy - - - - **[7.2. Innate Immunity]** - Noncellular specific functions - - - - - - - - Cellular specific functions - - - - - - - - - - **[7.3. Adaptive Immunity]** - Humoral - - - - - - - - - - - - - Cell-mediated - - - - - - - - - - Activation - - - - - Immune diseases - - - **[7.4. Lymphatic System]** - Anatomy and function - - - - **8. Digestive System** **[8.1. Digestive Anatomy and Functions]** - Alimentary canal (food tract) - - - - Oral cavity: food → bolus - - - Pharynx: naso/oro/laryngopharynx, epiglottis - Esophagus: peristalsis via PSNS, emesis (vomiting) - - - Stomach: bolus → chyme (acidic, semifluid, SA:V ↑) - - - - - - - - - Small intestine: absorbs water/nutrients and vit. (ADEK), villi → SA ↑, **[DJI]** **[I]**s **[F]**ucking **[B]**ad - - - - - - - - - Large intestine: absorbs water/salts - - - - - Anus: excretes feces **[8.2. Digestive Accessory Organs]** - Pancreas: made up of acinar cells, blood glucose regulation, secretes pancreatic juices - - - Liver: production of bile and albumin, bile ducts connect small intestine and gallbladder - - - - - - - Gallbladder: bile storage, bile secretion via biliary tree and pancreatic duct into duodenum - **9. Urinary System** **[9.1. Urinary Anatomy and Functions]** - Kidney: adrenal medulla (inner), adrenal cortex (outer), hilum, nephron - - - - - - - - - - - - - - - Bladder: internal (smooth)/external (skeletal) urethral sphincter - - Osmoregulation - - - - - Blood pressure regulation - - - **10. Integumentary System** **[10.1 Skin Anatomy and Functions]** - Epidermis - - - - - - - Dermis - - - - - - - - - Hypodermis: fat and fibrous tissue - Functions - - - - - - - - - - **11. Musculoskeletal System** **[11.1. Muscle Anatomy and Functions]** - Types of Muscle - - - - - - - Sarcomere: contractile unit of skeletal muscle (**[HIZAM]**), thick (myosin)/thin (actin) filaments - - - - - - Myocyte (muscle cell) - - - - Contraction - - - - - - - Summation: all or nothing response, contract more by using more muscle fibers - - Fatigue: energy reserve (**CP + ADP ⇌ creatine + ATP**), myoglobin (higher O~2~ affinity) **[11.2. Skeletal Anatomy and Functions]** - Skeleton: exoskeleton (arthropods), endoskeleton (vertebrates) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - **12. Genetics and Evolution** **[12.1. Genetics]** - Genes: DNA sequences encoding heritable traits, found in locus (location on chromosome) - - - - - - - - - - - - - - - - Laws of Mendel - - - - - - - DNA experiments - - - - - - - - - - - - Mutations: change in DNA sequence - - - - - - - - - - Genetic drift: random change in gene-pool composition - - - **[12.2. Evolution]** - Natural selection (Darwinism): heritable traits w/ high reproductive fitness are passed down - - - - - - - - Speciation - - - Patterns of evolution - - -