Chapter 4.2

• Regulatory mechanism: Active responses by plants induced by water balance changes

• Structural adaptations: Heritable physical traits that evolved in plants and help plants survive + reproduce under certain environmental conditions

Chapter 4.3

• Homeostasis: The internal environment remains constant even with external environment changes

  • Needs continual monitoring of key variables levels

• Set point: narrow range of values the body maintains

Chapter 4.7

Type 1 Diabetes Mellitus

• Diabetes mellitus: blood glucose too high → cell’s cannot take up glucose normally

  • large volumes of diabetes of sweet urine + extreme thirst

  • insulin producing beta cells of pancreas are destroyed by immune system → cannot make insulin

  • must have insulin injections to stabilise blood glucose levels

  1. Digestive system breaks down food + absorbs glucose → transported into blood

  2. Insulin (released by pancreas) signals to cells for glucose intake

  3. Cells take up glucose → used in cellular respiration

• Diabetes symptoms:

  • Frequent urination

  • Blurry vision

  • Increased hunger

  • Pins + needles feeling in feet

  • Weight loss

  • Extreme fatigue

  • Excessively thirsty

• Hyperthyroidism: Excessive production of thyroid hormones → drives basal metabolic rate + affects functions

  • High thyroxine levels in blood → metabolic rate increases

  • Low thyroxine levels → metabolic rate decreases

  • Metabolic disorders occur when the thyroid gland is overactive

• Grave’s Disease: Growth of nodules on thyroid or local inflammation

  • Immune cells target cells in thyroid gland

  • Antibodies act like pituitary hormone → produce excess thyroxine instead