B2 KO and Set pieces

• Homeostasis


  Regulating the internal conditions of the body (temperature, water levels, blood glucose)
• Central nervous system


  Made up of brain and spinal cord
• Endocrine system


  Hormonal system-involves glands, hormones and blood vessels
• Hormones


  Chemical messengers released by glands that travel in bloodstream
• Synapse


  Gap between 2 neurons. Signal passes between 2 neurons chemically
• Reflex response


  Fast response that protects us from harm
• Stages of reflex


  Stimulus, receptor, sensory neuron, relay neuron, motor neuron, effector, response
• Receptors


  • Eyes (sight), skin (temperature and pressure), ears (sound), nose (smell), tongue (taste)
• Effectors


  • Muscles (contract) or gland (releases chemical)
• Menstruation


  Uterus lining sheds
• Ovulation


  Egg is released from ovary
• Menstrual cycle


  Egg and sperm join (fertilisation)
• FSH


  Matures the egg
• Oestrogen


  Maintains the uterus lining
• LH


  Releases the egg (ovulation)
• Progesterone


  Thickens uterus lining, Inhibits FSH
• Thyroxine


  Stimulates the basal metabolic rate. Plays an important role in growth and development
• Adrenaline


  Produced in times of fear or stress. Increases the heart rate (more O2 and glucose delivery to brain and muscles). Prepares you for fight or flight
• Type 1 diabetes


  Pancreas fails to produce enough insulin. Treated with carbohydrate
• Type 2 diabetes


  Cells can no longer respond to insulin. Treated with insulin injections, controlled diet and exercise. Risk factor-obesity
• Major glands in body

  • Thyroid, adrenal, testes, pancreas, pituitary gland
• Glucose regulation


  1. Pancreas monitors glucose level

  2. If level too high, pancreas releases INSULIN

  3. INSULIN causes uptake of glucose by cells that convert glucose to GLYCOGEN

  4. If level too low, pancreas releases GLUCAGON

  5. GLUCAGON causes glycogen to be converted into glucose

  6. Glucose levels return to normal
• Fertility treatment


  FSH/LH given to mature and release more eggs
• IVF (in vitro fertilisation)


  Eggs collected and fertilised artificially, fertilised eggs develop into embryos implanted into mother's uterus. Emotionally and physically stressful, success rates are low, can lead to multiple births
• Contraceptive methods


  • Hormonal (oral contraceptive pill, skin patch, injection, implant)
  • Non-hormonal (condom, diaphragm, abstaining, sterilisation, spermicidal agents, intrauterine device)
• Sexual reproduction


  2 parents, genetic variation in offspring
• Asexual reproduction


  One parent, produces clones (genetically identical offspring)
• Mitosis


  Produces all body cells (except gametes), cell divides into two genetically identical daughter cells
• Meiosis


  Produces gametes only, cell divides twice to form four daughter cells, each with half the chromosomes of the parent cell
• DNA


  Polymer, made up of two strands forming a double helix
• Gene


  Small section of DNA on a chromosome, that codes for a particular protein
• Genome


  Entire genetic material of an organism
• Chromosomes


  Humans have 46 chromosomes in each cell, except gametes have 23 (half)
• Sex chromosomes


  Females-XX, males-XY
• Characteristics controlled by a single gene

  • Polydactyl, Cystic Fibrosis
• Allele


  A version of a gene
• Dominant


  Only 1 copy of allele is needed for condition to be expressed
• Recessive


  2 copies of the allele are needed for condition to be expressed
• Homozygous


  Same alleles present
• Heterozygous


  Different alleles present