Biology paper 2

• Homeostasis is keeping conditions inside your body the same
• What your body keeps the same

  blood glucose level

  pH of blood

  temperature

  carbon dioxide level

  Water
• Neurone is the nerve cells transmit electrical impulses between the brain, spinal cord or rest of your body
• Sensory neurneurone passes impulse from receptor to coordinator
• Motor neurone passes impulse from the coordinator to the effector
• Reaction time required practical

  Person 1 sits with arm resting on edge of table

  Person 2 holds ruler vertically between thumb and forefinger then let's go without warning

  Person 1 trying to catch ruler as fast as possible
• Hormones are chemical molecules released into blod
• Pituitary gland

  Produces many hormones that regulate body condition
• Ovaries

  Produce oestrogen
• Testes

  Produces testosterone
• Thyroid

  Produces thyroxine which is involved in regulating things like rate of metabolism, heart rate and temperature
• Adrenal Gland

  produces adrenaline which is used for fight or flight
• Pancreas

  Produces insulin which is used to regulate the blood glucose level
• NERVES VS HORMONES

  FAST SLOWER

  ACT FOR SHORT TIME ACT FOR LONG TIME

  PRECISE AREA GENERAL
• Blood glucose level is too high INSULIN is added
• Blood glucose level too low GLUCAGON is added
• TYPE 1 DIABETES

  the pancreas produces little or no insulin

  Persons blood glucose can rise to a level that could kill them

  Injections of insulin are normally needed
• Type 2 diabetes

  Person becomes resistant to their own insulin

  Causes blood sugar levels to rise to a dangerous level
• Stage 1 of menstrual cycle

  Day 1 menstruation begins the uterus lining breaks down for about 4 days
• Stage 2 of menstrstrual cycle

  The uterus lining builds up again from day 4-14 into a thick spongy layer full of blood vessels ready to receive a fertilised egg
• Stage 3 of menstrual cycle

  an egg develops and is released from the ovary at day 14 called ovulation
• Stage 4 of menstrual cycle

  Wall is maintained
• Menstrual cycle hormones

  FSH

  OESTROGEN

  LH

  PROGESTERONE
• FSH

  produced in pituitary gland

  Causes egg to mature in one of the ovaries in follicle

  Stimulate ovaries to produce oestrogen
• Oestrogen

  Produced in ovaries

  Causes lining of uterus to grow

  Stimulate the release of lh and inhibit release of FSH
• LH

  produced by pituitary gland

  Stimulate the release of an egg day 14
• Progesterone

  Produced in ovaries by the remains of the follicle after ovulation

  Maintain the lining of the uterus during the second half of the cycle when level of Progesterone falls the lining breaks down

  Inhibit the release of LH AND FSH
• Reasons against ivf

  Unethical because each embryo is potential human life

  Genetic testing could lead to selection of characteristics
• Glands release hormones
• Insulin triggers liver and muscle cells to store excess glucose
• Allele is an alternative form of the same gene
• Cystic fibrosis is a disorder of cell membranes
• Gene is a section of dna on a chromosome
• Gm is genetically modified
• Genetic engineering is to transfer a gene responsible for a desirable characteristics from one organism genome into another organism so it can have that characteristics
• Genetic engineering

  A useful gen is isolated from ones organism genome using enzymes and is inserted into a vector

  The vector is usually a virus or bacteria plasmid depending on the type of organism that the gene is being transferred to

  When the vector is introduced to the target organism the useful gene is inserted into cells
• Genetic engineering could solve problems like treating disease and more efficient food production
• CLASSIFICATION

  Kingdom

  Phylum

  Class

  Order

  Family

  Genus

  Species
• Plants compete for light water and space
• Animals compete for food water and mates