Paper 2

• What is homeostasis?


  The regulation of the internal conditions in a cell or organism to maintain optimum conditions for function in response to internal and external changes
• What key three factors does homeostasis in human control?

  Blood glucose concentration, body temperature, water levels
• What does the nervous system do in humans?

  Enable humans to react to their surroundings and to coordinate their behaviour
• What is the Central Nervous System?

  The brain and spinal cord
• What does the Central Nervous System do?


  Coordinates the response of effectors which may be muscles or gland secreting hormones
• What is the Central Nervous System sequence?

  Stimulus --> Receptor --> Coordinator --> Effector --> Response
• What is the endocrine system?

  A system composed of glands which secret chemicals called hormones directly into the bloodstream
• What is the pituitary gland?

  The 'master gland' in the brain which secretes hormones into the blood in response to body conditions
• What does the pancreas do?

  Monitor and control blood glucose concentration
• What happens when the blood glucose concentration is too high?

  The pancreas produces the hormone insulin that causes glucose to move from the blood into the cells
• H What happens when the blood glucose concentration is too low?

  The pancreas produces the hormone glucagon that causes glycogen to be converted into glucose and release into the blood
• What is glucose converted to in liver and muscle cells?

  Glycogen
• What is Type 1 diabetes?

  A disorder where the pancreas fails to produce sufficient insulin
• What is Type 2 diabetes?

  Where body cells no longer respond to insulin produced by the pancreas
• How do you treat Type 1 diabetes?

  Through insulin injections
• How do you treat Type 2 diabetes?

  Through a carbohydrate-controlled diet and exercise regime
• What is oestrogen?


  The main female reproductive hormone produced in the ovary
• What is ovulation?


  Where a mature egg is released
• What is testosterone?


  The main male reproductive hormone produced by the testes and it stimulates sperm production
• Name the hormones involved in the menstrual cycle

  Follicle stimulating hormone (FSH), Luteinising hormone (LH), Oestrogen, Progesterone
• What does Follicle stimulating hormone (FSH) cause?

  The maturation of an egg in the ovaries
• What does Luteinising hormone (LH) do


  Stimulates the release of the egg
• What is the role of Oestrogen and Progesterone?


  They are involved in maintaining the uterus lining
• What do oral contraceptives do?

  Contain hormones to inhibit FSH production so that no eggs mature
• How do injection, implant or skin patch contraceptives work?

  By slowly releasing progesterone to inhibit the maturation and release of eggs for a number of months or years
• Name two barrier methods of contraception

  Condom, diaphragms
• What is an intrauterine device?

  A device that prevents the implantation of an embryo or releases a hormone
• What do spermicidal agents do?

  Kill or disable sperm
• HT What are the four steps of In Vitro Fertilisation (IVF) treatment?

  A mother is given FSH and LH to stimulate maturation of several eggs, eggs are collected from the mother and fertilised by sperm from the father in the laboratory, the fertilised eggs develop into embryos. One or two embryos are inserted into the mother's uterus
• HT Give three negative about IVF

  Emotionally and physically stressful, success rates are not high, can lead to multiple births which are a risk to both babies and the mother
• HT What is adrenaline?


  A hormone produced by the adrenal gland in times of fear or stress
• HT What are the effects of adrenaline?

  Increases heart rate, boosts the delivery of oxygen and glucose to the brain and muscles
• HT What is thyroxine?


  A hormone produced by the thyroid gland that stimulates basal metabolic rate
• HT How are thyroxine levels controlled?

  By negative feedback
• What process leads to the formation of non-identical cells?

  Meiosis
• What process leads to the formation of identical cells?

  Mitosis
• What are the male gametes in animals?

  Sperm cells
• What are the female gametes in animals?

  Egg cells
• What are the male gametes in plants?

  Pollen cells
• What are the female gametes in plants?

  Eggs cells