Paper 2 Content

• 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 does the nervous system consist of?

  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 happens at the synapse?

  A neurotransmitter chemical transmits signals
• What is a reflex arc?

  A pathway that bypasses the brain for quick responses
• What are effectors?

  Muscles or glands that respond to signals
• How can reaction times be investigated?

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

  $t =$$\sqrt{\frac{2d}{g}}$
• What is thermoregulation?

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

  Sweat glands produce sweat, blood vessels dilate
• What happens when the body is too cold?

  Blood vessels constrict, muscles shiver
• What is the endocrine system?

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

  Pituitary gland
• What does the pancreas produce?

  Insulin
• What does insulin do?

  Regulates blood glucose levels
• What happens when blood glucose is too high?

  Pancreas secretes insulin to lower levels
• What happens when blood glucose is 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
• What is negative feedback?

  Body responds to return to normal conditions
• What hormone is involved in menstruation?

  FSH (Follicle Stimulating Hormone)
• What does estrogen do during menstruation?

  Thickens the uterus lining
• What is the role of LH?

  Triggers egg release from the ovary
• What is progesterone's role in menstruation?

  Maintains the uterus lining
• What are some contraception methods?

  Pills, injections, condoms, IUDs
• What is IVF?

  In vitro fertilization of eggs and sperm
• What does adrenaline do?

  Increases heart and breathing rates
• What does thyroxin control?

  Metabolic rate
• What is meiosis?

  Cell division to produce gametes
• What is the difference between diploid and haploid cells?

  Diploid has pairs of chromosomes, haploid has one
• What is a genome?

  All genetic material in an organism
• What is a gene?

  A section of DNA coding for a protein
• What is the human Genome Project?

  Mapping all human genes and their functions
• What is genotype?

  The genetic code stored in DNA
• What is phenotype?

  The expression of genetic traits in characteristics