BIOLOGY [NMAT]

• Hypertonic environment

  Cell has a lower concentration of solutes; higher water potential than surrounding extracellular fluid
• Osmosis


  Diffusion of water
• Erythrocyte in hypertonic solution


  • Crenate, become distorted in shape
• Hypotonic environment

  Cell has a higher concentration of solutes than the solution outside the cell which causes the cell to well
• Isotonic environment


  Cell has equal concentration with the solution outside the cell
• Membrane proteins

  • Act as enzymes and receptor sites; function for chemical transport, intercellular communication, cell-to-cell recognition, and attachment to the cytoskeleton and extracellular matrix
• Formation and transport of vesicles

  1. Secretory proteins assembled by ribosomes on rough ER, extruded into ER channels

  2. Enzymes in smooth ER modify some proteins

  3. Proteins pass through channels to Golgi body

  4. Proteins encapsulated in vesicles by Golgi body

  5. Vesicles pass through cytoplasm, fuse with plasma membrane and release contents
• Lymphocytes


  Subclass of white blood cells divided into B-lymphocytes and T-lymphocytes
• 1. lymphocytes


  Secrete antibodies for humoral immune response, binding to antigen and destroying it
• Non-specific defenses


  • Surface barriers
  • Defensive chemical cells
  • Cellular and chemical defenses like neutrophils and interferons
• 1. lymphocytes


  Processed in the thymus, initiate attack on foreign bodies
• Cell-mediated response


  Accomplished by T-lymphocytes, involves attacking virally infected cells and cancer cells
• Mutation


  Alteration of the form of a particular gene or chromosome that results in a new trait to be inherited
• Frameshift mutation


  The whole frame of the genetic sequence is changed
• Frameshift mutation

  • Insertion of "I"
  • THE CAT AND DOG RUN

  THE CAI TAN DDO GRU N
• Point mutation


  Only one nucleotide is modified to become another nucleotide
• Point mutation

  • THE CAT AND THE DOG RUN

  THE RAT AND THE DOG RUN
• Types of point mutation


  • Silent mutation - causes no change in protein activity
  • Missense mutation - results in change of protein activity
  • Nonsense mutation - results in shorter, non-functional protein
• Population density

  Population size per unit area/volume
• Factors affecting population density

  • Density-dependent factors - intensify as population increases
  • Density-independent factors - not related to population size
• Homeostasis


  Ability to maintain a stable internal environment
• Development

  Transform from immature to mature functional form
• Adaptation


  Structural modification in organisms that enables them to adjust to a changing environment
• Growth


  Irreversible increase in number, size and/or number of cells
• Meristems

  • Procambium - develops into vascular tissue
  • Protoderm - develops into surface/dermal tissues
  • Ground meristems - produces fundamental/ground tissues
  • Cork cambium - produces protective bark layer
• Five kingdoms


  • Monera
  • Protista - water mold
  • Fungi - yeast, mushroom, bread mold
  • Plantae
  • Animalia - shark, milkfish, turtle, snake
• Vitiligo


  Disorder where melanocytes are unable to function, resulting in white patches on skin
• Albinism

  Chromosomal mutation resulting in cessation or decline of melanin production
• Dihybrid cross

  Cross involving two traits
• Mendelian Laws of Inheritance

  Traits will segregate and assort independently
• Genotype

  Genetic makeup or genes of an individual
• Allele

  One of the alternative pair of genes, may be dominant or recessive
• Dominant allele


  Masks the effect of the recessive allele, represented by capital letter
• Recessive allele


  Masked by the dominant allele, represented by small letter
• Phenotype

  Physical appearance of an individual dictated by the genotype
• Antigen


  Any substance foreign to a body that evokes an immune response
• Antibody

  Proteins produced by B cells after antigen stimulation, act specifically against the antigen
• Blood types


  • Type A - has antigen A, antibody against B

  Type B - has antigen B, antibody against A

  Type AB - has antigens A and B, no antibody

  Type O - has no antigen, antibody against A and B
• Prokaryotes


  Do not have nuclear membrane, DNA exposed to cytoplasm; includes bacteria and blue-green algae
• Developmental biology


  Gametogenesis -> Fertilization -> Cleavage -> Gastrulation -> Organogenesis -> Growth and histological differentiation