Biology paper 2

• What topics does the AQA biology paper 2 cover?

  Homeostasis, inheritance, variation, evolution, ecology
• What is homeostasis?

  Regulation of internal conditions despite external changes
• Why is homeostasis important?

  It allows crucial chemical reactions to occur optimally
• What three internal conditions does the body regulate?

  Blood glucose concentration, temperature, water levels
• What are the components of the nervous system?

  CNS and PNS
• What does CNS stand for?

  Central Nervous System
• What is the role of receptors in the nervous system?

  They detect changes due to stimuli
• How does an electrical signal travel in the nervous system?

  Through sensory and relay neurons
• What is the gap between neurons called?

  Synapse
• What is a reflex arc?

  A pathway where signals bypass the brain
• What do glands produce in the body?

  Specific chemicals needed by the body
• How can you investigate reaction times?

  By dropping a ruler and measuring distance
• What is the formula to calculate reaction time from distance?

  $s =$$\frac{1}{2} a t^2$
• What is the role of the brain in thermoregulation?

  It senses blood temperature and sends signals
• What are the three parts of the brain mentioned?

  Cerebral cortex, cerebellum, medulla oblongata
• What does the cerebral cortex control?

  Higher level functions like memory and speech
• What is the function of the cerebellum?

  Motor skills, movement, balance, coordination
• What does the medulla oblongata control?

  Unconscious actions like heart rate
• What is the purpose of MRI scans?

  To see brain activity safely
• What is accommodation in the eye?

  Ability to change lens shape for focus
• How do ciliary muscles affect lens shape?

  They relax or contract to change thickness
• What happens to the lens when focusing on distant objects?

  The lens becomes thin and refracts less
• What happens to the lens when focusing on near objects?

  The lens becomes thicker and refracts more
• What is myopia?

  Shortsightedness
• What is hyperopia?

  Longsightedness
• How do glasses correct vision?

  By converging or diverging light before entry
• What is thermoregulation?

  Control of internal temperature by the body
• What happens when the body is too hot?

  Sweat glands produce sweat to cool down
• What is vasodilation?

  Widening of blood vessels to increase heat loss
• What happens when the body is too cold?

  Vasoconstriction occurs to retain heat
• What is the endocrine system?

  A system of glands that secrete hormones
• What is the main gland in the endocrine system?

  The pituitary gland
• What hormone does the pancreas produce?

  Insulin
• What does insulin do?

  Moves glucose from blood into cells
• What happens when blood glucose levels are too low?

  Pancreas produces glucagon to raise levels
• What is type 1 diabetes?

  Pancreas can't produce enough insulin
• What is type 2 diabetes?

  Cells no longer absorb glucose effectively
• How do kidneys maintain water balance?

  By filtering blood and producing urine
• What is ADH?

  Antidiuretic hormone produced by the pituitary gland
• What does ADH do in the kidneys?

  Causes reabsorption of more water