Admin Team
28 Dec

Biology Notes – Comprehensive


1. Human Body & Hormones

HormoneSourceFunction
OxytocinPituitary glandLabor, delivery, lactation, human behavior, milk release
Estrogen (Oestrogen)OvariesSex hormone, female characteristics
ProgesteroneOvariesSustains pregnancy
Insulinβ-cells of Islets of Langerhans, PancreasControls carbohydrate metabolism, regulates blood glucose
Glucagonα-cells of Islets of Langerhans, PancreasRaises blood glucose by glycogen breakdown
AdrenalineAdrenal glandsFight-or-flight response
AldosteroneAdrenal cortexRegulates water and salt balance
MelatoninPineal glandRegulates sleep, circadian rhythm
CalcitoninThyroid glandControls calcium balance

Other Notes:

  • Insulin is a protein hormone.
  • Pancreas: Endocrine & Exocrine gland
  • Endocrine glands: Pituitary, Thyroid
  • Exocrine glands: Salivary, Sweat, Lactating glands

2. Genetics & Molecular Biology

TopicDetail
Largest unitDNA
Smallest unitGene
MutationSudden change in DNA
OncogenesAssociated with cancer
DNA sequencingDetermines nucleotide variations in genetic diseases
Arthur KornbergSynthesized DNA in vitro

3. Vitamins

VitaminChemical NameDeficiency DiseaseSources
ARetinolNight blindness, XerophthalmiaEggs, liver, butter, spinach, carrot, mango
DCalciferolRicketsMilk, fish, liver oil, sunlight
D2ErgocalciferolRicketsPlant sources
D3CholecalciferolAnimal sources
ETocopherolMuscle damageGreen leafy vegetables, liver, eggs, nuts, seeds
KPhylloquinoneExcessive bleedingGreen leafy vegetables (broccoli, spinach, kale)
B1ThiamineBeri-BeriPork, nuts, seeds, eggs, whole grains
B2RiboflavinGrowth retardation, cheilosisMilk, green leafy vegetables, whole grains
B3NiacinPellagraMeat, fish, grains, poultry, mushroom
B6PyridoxineAnemia
B9Folic acid
B12CyanocobalaminAnemiaMeat, poultry, fish, seeds (not in plants)
CAscorbic acidLime, lemon, oranges, strawberries, tomato, papaya, mango

Vitamin Combinations:

  • Green leafy vegetables: A, E, K, B2
  • Eggs: A, E, B1
  • Liver: A, D, E
  • Meat/Fish: B3, B12
  • Fish: D
  • Vitamins C, B3, D can be synthesized; A, B1, B2, B5, B6, B7, B9, B12, E, K cannot.

4. Enzymes & Digestion

EnzymeSourceFunction
Ptyalin (Salivary amylase)Salivary glandsHydrolyzes starch → sugars
MaltaseSmall intestineConverts maltose → glucose
PepsinStomachProtein digestion
TrypsinPancreasProtein digestion
LipasePancreasFats → glycerol + fatty acids
ProteasePancreasProteins → amino acids
Alkaline phosphataseLiver

Other Notes:

  • Protein digestion starts in the stomach.
  • Salivary amylase is first enzyme acting on food.
  • Complete digestion of carbohydrates, proteins, fats occurs in the small intestine.
  • Triglycerides: fat in blood.
  • Collagen: most abundant in bones/tendons, provides strength.

5. Blood & Immunity

ComponentFunction
LymphocytesWhite blood cells, immune defense
ErythrocytesCarry oxygen using hemoglobin
ThrombocytesPlatelets, clot formation
Clinical deathPulse & heart beat stop

6. Reproductive System & Contraceptives

  • Contraceptives prevent unwanted pregnancies.
  • Oxytocin regulates lactation.
  • Mother’s milk lacks iron.
  • Prenuclear Transfer: mitochondrial replacement therapy for preventing mitochondrial disease.

Female mosquitoes: Anopheles body rests at an angle; Culex rests parallel to substratum.Bisexual flowers: Rose, Lily, Tulip, Mustard, Tomato, Hibiscus, Sunflower, Daffodil, Brinjal, Mango.

Unisexual flowers: Papaya, Coconut, Cucumber, Watermelon, White mulberry, Maize, Castor bean, Musk melon, Snake gourd, Tapioca.


7. Diseases & Vectors

DiseaseCausative agent / VectorVaccine / Treatment
TuberculosisMycobacterium tuberculosisBCG
TetanusClostridium tetaniATS / DTaP / Tdap
MalariaAnopheles mosquitoesChloroquine
FilariasisCulex quinquefasciatus
BotulismClostridium botulinum
Zika VirusVirus
LeprosyMycobacterium leprae
Alzheimer’sBrain disorder

Other:

  • Quinine (from Cinchona bark) treats malaria & babesiosis.
  • Cobalt-60: used in leukemia treatment.
  • Sulfa antibiotics: first used in 1930s, treat bacterial infections.

8. Microbiology

OrganismFeature
VirusesRequire host to reproduce
BacteriaCytoplasm present, used in medicines
ProtozoaAmoeba
FungiMulticellular, yeast reproduces by budding
MycoplasmaSmallest autonomous organism

9. Plant Biology

TopicDetail
Apical meristemGrowth in stem/root length
AerenchymaProvides buoyancy to aquatic plants
CollenchymaFlexibility in plants
ParenchymaLiving tissue
Meristematic tissueProduces new cells
Vegetative propagationAsexual reproduction via stems, roots, leaves
XylemUnidirectional water transport
CyanobacteriaFirst photosynthetic oxygen-liberating organisms, nitrogen fixation

Plant Types:

  • Moss → Bryophytes
  • Pine → Gymnosperms
  • Rose/Wheat → Angiosperms

Plant Tissue Notes:

  • Cell wall: cellulose
  • Vacuole: large central in plant, multiple small in animal
  • Chlorophyll contains magnesium

10. Animal Biology

TopicFeature
StapesSmallest bone
TendonsMuscle → bone
CartilageBone → bone
MusclesShorten (contract), lengthen (relax); sarcomere changes
Brain lobesMedulla: involuntary, heartbeat, breathing; Thalamus: sensory relay; Hypothalamus: temperature, appetite, hormones; Cerebellum: motor coordination
EyeRetina, iris controls pupil size
Lungs5 lobes (3 right, 2 left); alveoli → gas exchange

Other Notes:

  • Snail can change sex.
  • Birds: 13–25 cervical vertebrae.
  • Hydra: regeneration, budding
  • Echinodermata: free-living marine animals
  • Insectivorous plants grow in nitrogen-deficient soils

11. Cell Biology

OrganelleAnimalPlantFunction
NucleusPresentPresentGenetic control, cell division
MitochondriaPresentPresentEnergy production
Golgi apparatusPresentPresentTransport, secretion
RibosomesLargeSmallProtein synthesis
LysosomesPresentAbsentWaste disposal
CytoplasmPresentPresentMetabolism
Cell wallAbsentCelluloseStructural support
Plasma membranePresentPresentSemi-permeable barrier
VacuoleSmall/manyLarge/centralStorage

Other Notes:

  • Eukaryotic vs Prokaryotic differences: membrane-bound organelles present only in eukaryotes.
  • Viruses: no cytoplasm, require host.
  • Bacteria contain cytoplasm.

12. Chemistry in Biology

Compound / MaterialUse / Note
TeflonPolymer of tetrafluoroethylene
Vanaspati gheeHydrogen used in manufacture
Butane gasLighting cigarettes
LexanThermoplastic polycarbonate resin
DistillationSeparates mixture based on boiling point
Tartaric acidUnripe mangoes, grapes
Formic acidAnts
Acetic acidVinegar

13. Nutrition

FoodNutrients
MilkWater 87.5%, Protein 3.4%, Fat 3.9%, Lactose & Minerals 5.2%, Calcium, Mg, P, Vit D, Vit B12, K, Zinc
Human energy storageGlycogen in liver & muscles

14. Miscellaneous Facts

  • Hair, spider silk, hoof → Protein
  • Fibroin → medical applications
  • Silk gland produces fibroin & sericin
  • Mother’s milk lacks iron
  • Clinical death: heart & pulse stop
  • Gambusia fish → biological mosquito control
  • Alveoli: site of gaseous exchange
  • Eutrophication → algal bloom, oxygen depletion, affects biodiversity
  • Prion & virus: require host
  • Alzheimer’s → memory loss
  • Schizophrenia → affects thinking, behavior
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