night before revision

• ovulation is the release of an egg from the ovary, which is triggered by the hormone oestrogen
• The role of FSH in menstrual cycle is to stimulate the development of the follicles
• The role of the LH in the menstrual cycle is to leutinise the ovaries
• The role of oestrogen and progesterone in the menstrual cycle is to maintain the lining of the uterus
• ways in which slow-release progesterone may be used as a contraceptive: injection, implant, skin patch
• IVF stands for in vitro fertilisation
• eggs are fertalised in IVF by sperm in a labatory
• the stage when embryos are implanted into the mother is when they are tiny balls of cells
• ''specialised'' means physically adapted for their function
• muscles cells have lots of mitochondria for energy
• xylem cells are strengthened by lignin
• phloem cells have perfonated ends
• a stem cell is an undifferentiated cell with the ability to turn into many different cell types
• theraputic cloning is when an embryo is produced with the same genes as the patient
• embryos arent rejected by patients body from the embryo because they contain the same genes
• diffusion is the spreading out of particles from an area of higher concentration to an area of lower concentration
• oxygen diffuses from the lungs into the blood stream. carbon dioxide diffuses from the blood stream into the lungs
• osmosis is the movement of water from a dilute solution to a concentrated solution passed through a partially permeable membrane
• active transport is the movement of solutes from a more dilute solution to a more concentrated solution across a partially permeable membrane
• features of cells undertaking active transport is carrier proteins and additional mitochondria
• active transport is used to absorb sugar in the intestines
• active transport is used to absorb mineral ions in plant root hairs
• 2 ways that bacteria can be cultured: in a nutrient broth solution or as colonies on a agar gel plate
• reasons why uncontaminated culture of microorganisms are required is for investigating the action of disinfectants and antibiotics
• an ecosystem is a community of organisms and their physical environment.
• it is important that blood glucose concentration be maintained to maintain energy levels and to protect the cells from motic shock
• the bodies response to insulin is the glucose is absorbed by the liver and muscles and converted into insoluble glycogen
• diabetes is a chronic illness in which the body is unable to control the levels of glucose in the blood
• the role of the hormone secreted by the thyroid gland is to stimulate basal metabolic rate
• a hormone is a protein chemical messeneger, secreted from gland and carried in the blood to a target organ
• a gland is a group of cells that secrete a substance
• a reflex action is an automatic response
• effector organs bring about responses which restore optimum levels
• information is transported by the nervous systems as electrical impulses
• 3 examples of coordination centres are: brain, spinal cord, pancreas
• coordination centres recieve and process information from receptors
• homeostasis is important for enzymes as it maintains optimum conditions
• the 3 parts of each control system are the receptor, the coordination centre and the effector
• anaerobic respiration is yeast cells= glucose-->ethanol+carbon dioxide
• 3 things that new medical drugs are tested for before being used are : toxicity, efficacy and dosage